blob: ba2f679044fe4c01f639bc2deeed68fdf4ff20f1 [file] [log] [blame]
Tim Peters84362bc2001-10-19 17:55:30 +00001What's New in Python 2.2b2?
2XXX Planned XXX Release date: 14-Nov-2001
3===========================
4
5Type/class unification and new-style classes
6
Tim Petersa427a2b2001-10-29 22:25:45 +00007- The new builtin dictionary() constructor, and dictionary type, have
8 been renamed to dict. This reflects a decade of common usage.
9
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +000010- New-style classes can now have a __del__ method, which is called
11 when the instance is deleted (just like for classic classes).
12
Guido van Rossum12d955c2001-10-26 14:56:06 +000013- Assignment to object.__dict__ is now possible, for objects that are
14 instances of new-style classes that have a __dict__ (unless the base
15 class forbids it).
16
Tim Peters1fc240e2001-10-26 05:06:50 +000017- dictionary() now accepts an iterable object producing 2-sequences.
18 For example, dictionary(d.items()) == d for any dictionary d. The
19 argument, and the elements of the argument, can be any iterable
20 objects.
21
Guido van Rossumc8e56452001-10-22 00:43:43 +000022- Methods of built-in types now properly check for keyword arguments
23 (formerly these were silently ignored). The only built-in methods
24 that take keyword arguments are __call__, __init__ and __new__.
25
Guido van Rossum86443212001-10-27 22:28:54 +000026- The socket function has been converted to a type; see below.
27
Tim Peters84362bc2001-10-19 17:55:30 +000028Core and builtins
29
Guido van Rossum12d955c2001-10-26 14:56:06 +000030- Clarified the error messages for unsupported operands to an operator
31 (like 1 + '').
32
Tim Peters84362bc2001-10-19 17:55:30 +000033Extension modules
34
Guido van Rossum12d955c2001-10-26 14:56:06 +000035- The socket module defines a new method for socket objects,
36 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +000037 send() until all data has been sent. Also, the socket function has
38 been converted to a subclassable type, like list and tuple (etc.)
39 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +000040
41- Various bugfixes to the curses module. There is now a test suite
42 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000043
Guido van Rossum692adf12001-10-30 03:03:03 +000044- binascii.b2a_base64 no longer places an arbitrary restriction of 57
45 bytes on its input.
46
Tim Peters84362bc2001-10-19 17:55:30 +000047Library
48
Martin v. Löwisb7b32602001-11-02 23:48:20 +000049- Tix exposes more commands through the classes DirSelectBox,
50 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
51 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
52 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
53
Tim Peters98791af2001-10-23 01:59:54 +000054- Traceback objects are now scanned by cyclic garbage collection, so
55 cycles created by casual use of sys.exc_info() no longer cause
56 permanent memory leaks (provided garbage collection is enabled).
57
Guido van Rossum49192142001-10-24 20:51:44 +000058- os.extsep -- a new variable needed by the RISCOS support. It is the
59 separator used by extensions, and is '.' on all platforms except
60 RISCOS, where it is '/'. There is no need to use this variable
61 unless you have a masochistic desire to port your code to RISCOS.
62
Tim Peters84362bc2001-10-19 17:55:30 +000063Tools/Demos
64
65Build
66
67C API
68
Tim Peters1fc240e2001-10-26 05:06:50 +000069- New function PySequence_Fast_GET_SIZE() returns the size of a non-
70 NULL result from PySequence_Fast(), more quickly than calling
71 PySequence_Size().
72
Tim Peters84362bc2001-10-19 17:55:30 +000073New platforms
74
Guido van Rossum86443212001-10-27 22:28:54 +000075- We've finally confirmed that this release builds on HP-UX 11.00,
76 *with* threads, and passes the test suite.
77
Guido van Rossum49192142001-10-24 20:51:44 +000078- Updated RISCOS port by Dietmar Schwertberger.
79
Tim Peters84362bc2001-10-19 17:55:30 +000080Tests
81
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000082- Added a test script for the curses module. It isn't run automatically;
83 regrtest.py must be run with '-u curses' to enable it.
84
Tim Peters84362bc2001-10-19 17:55:30 +000085Windows
86
87
Tim Petersabf925f2001-09-28 21:53:42 +000088What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +000089Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +000090===========================
91
92Type/class unification and new-style classes
93
Guido van Rossum687ae002001-10-15 22:03:32 +000094- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +000095 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +000096 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000097 remains: the __dict__ of a new-style class is a read-only proxy; you
98 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000099 __defined__ attribute of new-style types no longer exists, for lack
100 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000101 future a __cache__ may be resurrected with a similar function, if I
102 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000103
Tim Peters1c9ca872001-10-04 06:43:12 +0000104- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
105 always returned None, even when there was a class docstring).
106
107- doctest now finds and runs docstrings attached to new-style classes,
108 class methods, static methods, and properties.
109
Guido van Rossum9074ef62001-10-16 21:34:49 +0000110Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000111
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000112- A very subtle syntactical pitfall in list comprehensions was fixed.
113 For example: [a+b for a in 'abc', for b in 'def']. The comma in
114 this example is a mistake. Previously, this would silently let 'a'
115 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
116 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
117 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
118 Note that [a for a in <singleton>] is a convoluted way to say
119 [<singleton>] anyway, so it's not like any expressiveness is lost.
120
Guido van Rossum9074ef62001-10-16 21:34:49 +0000121- getattr(obj, name, default) now only catches AttributeError, as
122 documented, rather than returning the default value for all
123 exceptions (which could mask bugs in a __getattr__ hook, for
124 example).
125
Fred Drakecb7a6b52001-10-22 18:41:51 +0000126- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000127 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000128 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000129 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000130
Guido van Rossum1c486092001-10-19 02:05:35 +0000131- unicode(obj) now behaves more like str(obj), accepting arbitrary
132 objects, and calling a __unicode__ method if it exists.
133 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000134 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000135
Barry Warsawf6fb1712001-10-19 05:35:40 +0000136- isinstance() now allows any object as the first argument and a
137 class, a type or something with a __bases__ tuple attribute for the
138 second argument. The second argument may also be a tuple of a
139 class, type, or something with __bases__, in which case isinstance()
140 will return true if the first argument is an instance of any of the
141 things contained in the second argument tuple. E.g.
142
143 isinstance(x, (A, B))
144
145 returns true if x is an instance of A or B.
146
Guido van Rossum9074ef62001-10-16 21:34:49 +0000147Extension modules
148
149- thread.start_new_thread() now returns the thread ID (previously None).
150
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000151- binascii has now two quopri support functions, a2b_qp and b2a_qp.
152
Guido van Rossumc524d952001-10-19 01:31:59 +0000153- readline now supports setting the startup_hook and the
154 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000155
Guido van Rossumc524d952001-10-19 01:31:59 +0000156- os and posix supports chroot(), setgroups() and unsetenv() where
157 available. The stat(), fstat(), statvfs() and fstatvfs() functions
158 now return "pseudo-sequences" -- the various fields can now be
159 accessed as attributes (e.g. os.stat("/").st_mtime) but for
160 backwards compatibility they also behave as a fixed-length sequence.
161 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000162 attributes.
163
164- time: localtime(), gmtime() and strptime() now return a
165 pseudo-sequence similar to the os.stat() return value, with
166 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000167
Guido van Rossum9074ef62001-10-16 21:34:49 +0000168- Decompression objects in the zlib module now accept an optional
169 second parameter to decompress() that specifies the maximum amount
170 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000171
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000172- optional SSL support in the socket module now exports OpenSSL
173 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
174 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000175 automatically seed its PRNG. Also, the keyfile and certfile
176 arguments to socket.ssl() are now optional.
177
178- posixmodule (and by extension, the os module on POSIX platforms) now
179 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000180
Guido van Rossum9074ef62001-10-16 21:34:49 +0000181Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000182
Tim Peters7402f792001-10-02 03:53:41 +0000183- doctest now excludes functions and classes not defined by the module
184 being tested, thanks to Tim Hochberg.
185
Fred Drakecb7a6b52001-10-22 18:41:51 +0000186- HotShot, a new profiler implemented using a C-based callback, has
187 been added. This substantially reduces the overhead of profiling,
188 but it is still quite preliminary. Support modules and
189 documentation will be added in upcoming releases (before 2.2 final).
190
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000191- profile now produces correct output in situations where an exception
192 raised in Python is cleared by C code (e.g. hasattr()). This used
193 to cause wrong output, including spurious claims of recursive
194 functions and attribution of time spent to the wrong function.
195
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000196 The code and documentation for the derived OldProfile and HotProfile
197 profiling classes was removed. The code hasn't worked for years (if
198 you tried to use them, they raised exceptions). OldProfile
199 intended to reproduce the behavior of the profiler Python used more
200 than 7 years ago, and isn't interesting anymore. HotProfile intended
201 to provide a faster profiler (but producing less information), and
202 that's a worthy goal we intend to meet via a different approach (but
203 without losing information).
204
Tim Peterscce092d2001-10-09 05:31:56 +0000205- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000206 a much better system-specific calibration constant. The constant can
207 now be specified in an instance constructor, or as a Profile class or
208 instance variable, instead of by editing profile.py's source code.
209 Calibration must still be done manually (see the docs for the profile
210 module).
211
212 Note that Profile.calibrate() must be overriden by subclasses.
213 Improving the accuracy required exploiting detailed knowledge of
214 profiler internals; the earlier method abstracted away the details
215 and measured a simplified model instead, but consequently computed
216 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000217
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000218- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000219 which indicates whether output is intended for the header 'Q'
220 encoding.
221
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000222- The SocketServer.ThreadingMixIn class now closes the request after
223 finish_request() returns. (Not when it errors out though.)
224
Barry Warsawf6fb1712001-10-19 05:35:40 +0000225- The nntplib module's NNTP.body() method has grown a `file' argument
226 to allow saving the message body to a file.
227
228- The email package has added a class email.Parser.HeaderParser which
229 only parses headers and does not recurse into the message's body.
230 Also, the module/class MIMEAudio has been added for representing
231 audio data (contributed by Anthony Baxter).
232
233- ftplib should be able to handle files > 2GB.
234
235- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
236 ON, and OFF.
237
Fred Drakecb7a6b52001-10-22 18:41:51 +0000238- xml.dom.minidom NodeList objects now support the length attribute
239 and item() method as required by the DOM specifications.
240
Guido van Rossumed554f62001-10-02 23:15:37 +0000241Tools/Demos
242
243- Demo/dns was removed. It no longer serves any purpose; a package
244 derived from it is now maintained by Anthony Baxter, see
245 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000246
Barry Warsawf6fb1712001-10-19 05:35:40 +0000247- The freeze tool has been made more robust, and two new options have
248 been added: -X and -E.
249
Tim Petersabf925f2001-09-28 21:53:42 +0000250Build
251
Barry Warsawf6fb1712001-10-19 05:35:40 +0000252- configure will use CXX in LINKCC if CXX is used to build main() and
253 the system requires to link a C++ main using the C++ compiler.
254
Tim Petersabf925f2001-09-28 21:53:42 +0000255C API
256
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000257- The documentation for the tp_compare slot is updated to require that
258 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
259 not correct. This is not yet enforced but will be enforced in
260 Python 2.3; even later, we may use -2 to indicate errors and +2 for
261 "NotImplemented". Right now, -1 should be used for an error return.
262
Tim Petersd38b1c72001-09-30 05:09:37 +0000263- PyLong_AsLongLong() now accepts int (as well as long) arguments.
264 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
265 as long) arguments.
266
Guido van Rossum3c288632001-10-16 21:13:49 +0000267- PyThread_start_new_thread() now returns a long int giving the thread
268 ID, if one can be calculated; it returns -1 for error, 0 if no
269 thread ID is calculated (this is an incompatible change, but only
270 the thread module used this API). This code has only really been
271 tested on Linux and Windows; other platforms please beware (and
272 report any bugs or strange behavior).
273
Guido van Rossum1c486092001-10-19 02:05:35 +0000274- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
275 input.
276
Tim Petersabf925f2001-09-28 21:53:42 +0000277New platforms
278
279Tests
280
281Windows
282
Tim Peters04cf1d32001-10-09 22:39:40 +0000283- Installer: If you install IDLE, and don't disable file-extension
284 registration, a new "Edit with IDLE" context (right-click) menu entry
285 is created for .py and .pyw files.
286
Tim Peters1ce3cf72001-10-01 17:58:40 +0000287- The signal module now supports SIGBREAK on Windows, thanks to Steven
288 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
289 action remains to call Win32 ExitProcess(). This can be changed via
290 signal.signal(). For example:
291
292 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
293 # (SIGINT) behavior.
294 import signal
295 signal.signal(signal.SIGBREAK,
296 signal.default_int_handler)
297
298 try:
299 while 1:
300 pass
301 except KeyboardInterrupt:
302 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
303 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
304 # program without the possibility for any Python-level cleanup).
305 print "Clean exit"
306
Tim Petersabf925f2001-09-28 21:53:42 +0000307
Tim Petersb07352e2001-09-08 01:25:47 +0000308What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000309Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000310===========================
311
Guido van Rossum808eea72001-09-25 04:15:41 +0000312Type/class unification and new-style classes
313
314- pydoc and inspect are now aware of new-style classes;
315 e.g. help(list) at the interactive prompt now shows proper
316 documentation for all operations on list objects.
317
318- Applications using Jim Fulton's ExtensionClass module can now safely
319 be used with Python 2.2. In particular, Zope 2.4.1 now works with
320 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
321 examples also work again. It is hoped that Gtk and Boost also work
322 with 2.2a4 and beyond. (If you can confirm this, please write
323 webmaster@python.org; if there are still problems, please open a bug
324 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000325
Tim Peters66c1a522001-09-24 21:17:50 +0000326- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
327 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
328 in the constructed property object. fget, fset and fdel weren't
329 discoverable from Python in 2.2a3. __doc__ is new, and allows to
330 associate a docstring with a property.
331
Guido van Rossum808eea72001-09-25 04:15:41 +0000332- Comparison overloading is now more completely implemented. For
333 example, a str subclass instance can properly be compared to a str
334 instance, and it can properly overload comparison. Ditto for most
335 other built-in object types.
336
337- The repr() of new-style classes has changed; instead of <type
338 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
339 *except* for built-in types, which are still rendered as <type
340 'Foo'> (to avoid upsetting existing code that might parse or
341 otherwise rely on repr() of certain type objects).
342
343- The repr() of new-style objects is now always <Foo object at XXX>;
344 previously, it was sometimes <Foo instance at XXX>.
345
346- For new-style classes, what was previously called __getattr__ is now
347 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000348 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000349 one in classic classes is defined which is called only if regular
350 attribute access raises AttributeError; to catch *all* attribute
351 access, you can use __getattribute__ (for new-style classes). If
352 both are defined, __getattribute__ is called first, and if it raises
353 AttributeError, __getattr__ is called.
354
355- The __class__ attribute of new-style objects can be assigned to.
356 The new class must have the same C-level object layout as the old
357 class.
358
359- The builtin file type can be subclassed now. In the usual pattern,
360 "file" is the name of the builtin type, and file() is a new builtin
361 constructor, with the same signature as the builtin open() function.
362 file() is now the preferred way to open a file.
363
364- Previously, __new__ would only see sequential arguments passed to
365 the type in a constructor call; __init__ would see both sequential
366 and keyword arguments. This made no sense whatsoever any more, so
367 now both __new__ and __init__ see all arguments.
368
369- Previously, hash() applied to an instance of a subclass of str or
370 unicode always returned 0. This has been repaired.
371
372- Previously, an operation on an instance of a subclass of an
373 immutable type (int, long, float, complex, tuple, str, unicode),
374 where the subtype didn't override the operation (and so the
375 operation was handled by the builtin type), could return that
376 instance instead a value of the base type. For example, if s was of
377 a str sublass type, s[:] returned s as-is. Now it returns a str
378 with the same value as s.
379
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000380- Provisional support for pickling new-style objects has been added.
381
Guido van Rossum808eea72001-09-25 04:15:41 +0000382Core
383
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000384- file.writelines() now accepts any iterable object producing strings.
385
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000386- PyUnicode_FromEncodedObject() now works very much like
387 PyObject_Str(obj) in that it tries to use __str__/tp_str
388 on the object if the object is not a string or buffer. This
389 makes unicode() behave like str() when applied to non-string/buffer
390 objects.
391
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000392- PyFile_WriteObject now passes Unicode objects to the file's write
393 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000394 of a print statement must support Unicode objects, i.e. they must
395 at least convert them into ASCII strings.
396
Guido van Rossum624c8af2001-09-18 15:21:04 +0000397- Thread scheduling on Solaris should be improved; it is no longer
398 necessary to insert a small sleep at the start of a thread in order
399 to let other runnable threads be scheduled.
400
Tim Petersb07352e2001-09-08 01:25:47 +0000401Library
402
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000403- StringIO.StringIO instances and cStringIO.StringIO instances support
404 read character buffer compatible objects for their .write() methods.
405 These objects are converted to strings and then handled as such
406 by the instances.
407
Barry Warsaw2f600732001-09-24 04:28:10 +0000408- The "email" package has been added. This is basically a port of the
409 mimelib package <http://sf.net/projects/mimelib> with API changes
410 and some implementations updated to use iterators and generators.
411
Tim Peters8a9c2842001-09-22 21:30:22 +0000412- difflib.ndiff() and difflib.Differ.compare() are generators now. This
413 restores the ability of Tools/scripts/ndiff.py to start producing output
414 before the entire comparison is complete.
415
Barry Warsaw58b072d2001-09-22 04:44:21 +0000416- StringIO.StringIO instances and cStringIO.StringIO instances support
417 iteration just like file objects (i.e. their .readline() method is
418 called for each iteration until it returns an empty string).
419
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000420- The codecs module has grown four new helper APIs to access
421 builtin codecs: getencoder(), getdecoder(), getreader(),
422 getwriter().
423
Guido van Rossum624c8af2001-09-18 15:21:04 +0000424- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
425 simplifies writing XML RPC servers.
426
Barry Warsaw647d5e82001-09-28 17:01:02 +0000427- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000428 after interpretation of symbolic links. On non-Unix systems, this
429 is an alias for os.path.abspath().
430
Tim Peters16a77ad2001-09-08 04:00:12 +0000431- operator.indexOf() (PySequence_Index() in the C API) now works with any
432 iterable object.
433
Guido van Rossum624c8af2001-09-18 15:21:04 +0000434- smtplib now supports various authentication and security features of
435 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000436
Guido van Rossum624c8af2001-09-18 15:21:04 +0000437- hmac: a new module implementing keyed hashing for message
438 authentication.
439
440- mimetypes now recognizes more extensions and file types. At the
441 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000442
Guido van Rossum624c8af2001-09-18 15:21:04 +0000443- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000444 Python 2.2 bytecode generation. It has also been promoted from a
445 Tool to a standard library package. (Tools/compiler still exists as
446 a sample driver.)
447
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000448Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000449
Tim Petersb07352e2001-09-08 01:25:47 +0000450Build
451
Guido van Rossum624c8af2001-09-18 15:21:04 +0000452- Large file support (LFS) is now automatic when the platform supports
453 it; no more manual configuration tweaks are needed. On Linux, at
454 least, it's possible to have a system whose C library supports large
455 files but whose kernel doesn't; in this case, large file support is
456 still enabled but doesn't do you any good unless you upgrade your
457 kernel or share your Python executable with another system whose
458 kernel has large file support.
459
460- The configure script now supplies plausible defaults in a
461 cross-compilation environment. This doesn't mean that the supplied
462 values are always correct, or that cross-compilation now works
463 flawlessly -- but it's a first step (and it shuts up most of
464 autoconf's warnings about AC_TRY_RUN).
465
466- The Unix build is now a bit less chatty, courtesy of the parser
467 generator. The build is completely silent (except for errors) when
468 using "make -s", thanks to a -q option to setup.py.
469
Tim Petersb07352e2001-09-08 01:25:47 +0000470C API
471
Guido van Rossum624c8af2001-09-18 15:21:04 +0000472- The "structmember" API now supports some new flag bits to deny read
473 and/or write access to attributes in restricted execution mode.
474
Tim Petersb07352e2001-09-08 01:25:47 +0000475New platforms
476
Guido van Rossum624c8af2001-09-18 15:21:04 +0000477- Compaq's iPAQ handheld, running the "familiar" Linux distribution
478 (http://familiar.handhelds.org).
479
Tim Petersb07352e2001-09-08 01:25:47 +0000480Tests
481
Tim Peters8a9c2842001-09-22 21:30:22 +0000482- The "classic" standard tests, which work by comparing stdout to
483 an expected-output file under Lib/test/output/, no longer stop at
484 the first mismatch. Instead the test is run to completion, and a
485 variant of ndiff-style comparison is used to report all differences.
486 This is much easier to understand than the previous style of reporting.
487
488- The unittest-based standard tests now use regrtest's test_main()
489 convention, instead of running as a side-effect of merely being
490 imported. This allows these tests to be run in more natural and
491 flexible ways as unittests, outside the regrtest framework.
492
493- regrtest.py is much better integrated with unittest and doctest now,
494 especially in regard to reporting errors.
495
Tim Petersb07352e2001-09-08 01:25:47 +0000496Windows
497
Guido van Rossum624c8af2001-09-18 15:21:04 +0000498- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000499 that support it (NTFS under Windows 2000). See "What's New in
500 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000501
Tim Petersb07352e2001-09-08 01:25:47 +0000502
Tim Petersedc99312001-08-22 21:36:50 +0000503What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000504Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000505===========================
506
507Core
508
Tim Peters9fffa3e2001-09-04 05:14:19 +0000509- Conversion of long to float now raises OverflowError if the long is too
510 big to represent as a C double.
511
Tim Peters32f453e2001-09-03 08:35:41 +0000512- The 3-argument builtin pow() no longer allows a third non-None argument
513 if either of the first two arguments is a float, or if both are of
514 integer types and the second argument is negative (in which latter case
515 the arguments are converted to float, so this is really the same
516 restriction).
517
Tim Peters5d2b77c2001-09-03 05:47:38 +0000518- The builtin dir() now returns more information, and sometimes much
519 more, generally naming all attributes of an object, and all attributes
520 reachable from the object via its class, and from its class's base
521 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
522 an empty list. In 2.2a3,
523
524 >>> dir([])
525 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
526 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
527 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
528 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
529 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
530 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
531 'reverse', 'sort']
532
533 dir(module) continues to return only the module's attributes, though.
534
Tim Petersbdee63f2001-09-02 03:40:59 +0000535- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000536 than raising OverflowError. This is a partial implementation of PEP
537 237. You can use -Wdefault::OverflowWarning to enable a warning for
538 this situation, and -Werror::OverflowWarning to revert to the old
539 OverflowError exception.
540
Guido van Rossum61c345f2001-09-04 03:26:15 +0000541- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000542 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000543 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
544 -Qold, meaning the / operator has its classic meaning and no
545 warnings are issued. Using -Qwarn issues a run-time warning about
546 all uses of classic division for int and long arguments; -Qwarnall
547 also warns about classic division for float and complex arguments
548 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
549 new division by default, but only in the __main__ module. You can
550 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
551 __main__ module new division, and warns about classic division
552 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000553
Tim Petersbdee63f2001-09-02 03:40:59 +0000554- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000555 long, float, str, unicode, and tuple. (The types complex, list and
556 dictionary can also be subclassed; this was introduced earlier.)
557 Note that restrictions apply when subclassing immutable built-in
558 types: you can only affect the value of the instance by overloading
559 __new__. You can add mutable attributes, and the subclass instances
560 will have a __dict__ attribute, but you cannot change the "value"
561 (as implemented by the base class) of an immutable subclass instance
562 once it is created.
563
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000564- The dictionary constructor now takes an optional argument, a
565 mapping-like object, and initializes the dictionary from its
566 (key, value) pairs.
567
Tim Petersbdee63f2001-09-02 03:40:59 +0000568- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000569 "cooperative super calls" in a multiple inheritance setting. For an
570 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
571
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000572- A new built-in type, property, has been added. This enables the
573 creation of "properties". These are attributes implemented by
574 getter and setter functions (or only one of these for read-only or
575 write-only attributes), without the need to override __getattr__.
576 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000577
Tim Petersbdee63f2001-09-02 03:40:59 +0000578- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000579 liberalized, to allow leading zeroes. Examples of literals now
580 legal that were SyntaxErrors before:
581
582 00.0 0e3 0100j 07.5 00000000000000000008.
583
Tim Petersbdee63f2001-09-02 03:40:59 +0000584- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000585 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
586
Tim Petersedc99312001-08-22 21:36:50 +0000587Library
588
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000589- telnetlib includes symbolic names for the options, and support for
590 setting an option negotiation callback.
591
Tim Petersa40c7932001-09-05 22:36:56 +0000592- The new C standard no longer requires that math libraries set errno to
593 ERANGE on overflow. For platform libraries that exploit this new
594 freedom, Python's overflow-checking was wholly broken. A new overflow-
595 checking scheme attempts to repair that, but may not be reliable on all
596 platforms (C doesn't seem to provide anything both useful and portable
597 in this area anymore).
598
Martin v. Löwis44f86962001-09-05 13:44:54 +0000599- Asynchronous timeout actions are available through the new class
600 threading.Timer.
601
Tim Peters78526162001-09-05 00:53:45 +0000602- math.log and math.log10 now return sensible results for even huge
603 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
604
Tim Petersbdee63f2001-09-02 03:40:59 +0000605- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000606 currently held. See the docs for the imp module.
607
Tim Petersbdee63f2001-09-02 03:40:59 +0000608- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000609 dumps containing ints written on platforms where Python ints are 8 bytes.
610 When read on a box where Python ints are 4 bytes, such values are
611 converted to Python longs.
612
Tim Petersbdee63f2001-09-02 03:40:59 +0000613- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000614 code objects is no longer allowed. This plugs a security hole.
615
Steve Purcell6091cd62001-09-06 16:05:17 +0000616- unittest.TestResult instances no longer store references to tracebacks
617 generated by test failures. This prevents unexpected dangling references
618 to objects that should be garbage collected between tests.
619
Tim Petersedc99312001-08-22 21:36:50 +0000620Tools
621
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000622- Tools/scripts/fixdiv.py has been added which can be used to fix
623 division operators as per PEP 238.
624
Tim Petersedc99312001-08-22 21:36:50 +0000625Build
626
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000627- If you are an adventurous person using Mac OS X you may want to look at
628 Mac/OSX. There is a Makefile there that will build Python as a real Mac
629 application, which can be used for experimenting with Carbon or Cocoa.
630 Discussion of this on pythonmac-sig, please.
631
Tim Peters7eea37e2001-09-04 22:08:56 +0000632C API
633
634- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000635
Tim Peters9fffa3e2001-09-04 05:14:19 +0000636- Note that PyLong_AsDouble can fail! This has always been true, but no
637 callers checked for it. It's more likely to fail now, because overflow
638 errors are properly detected now. The proper way to check:
639
640 double x = PyLong_AsDouble(some_long_object);
641 if (x == -1.0 && PyErr_Occurred()) {
642 /* The conversion failed. */
643 }
644
Tim Petersbdee63f2001-09-02 03:40:59 +0000645- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000646 compile but will not participate in GC. To upgrade an extension
647 module:
648
649 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000650
Neil Schemenauer4042c692001-08-30 15:38:01 +0000651 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
652 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000653
Neil Schemenauer4042c692001-08-30 15:38:01 +0000654 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
655 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000656
Neil Schemenauer4042c692001-08-30 15:38:01 +0000657 - remove PyGC_HEAD_SIZE from object size calculations
658
659 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
660
Tim Petersbdee63f2001-09-02 03:40:59 +0000661- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000662 These can be used safely to construct string objects from a
663 sprintf-style format string (similar to the format string supported
664 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000665
Tim Petersedc99312001-08-22 21:36:50 +0000666New platforms
667
Tim Petersb7da0902001-09-02 23:01:43 +0000668- Stephen Hansen contributed patches sufficient to get a clean compile
669 under Borland C (Windows), but he reports problems running it and ran
670 out of time to complete the port. Volunteers? Expect a MemoryError
671 when importing the types module; this is probably shallow, and
672 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000673
Tim Petersedc99312001-08-22 21:36:50 +0000674Tests
675
676Windows
677
Tim Peters6e13a562001-09-06 00:32:15 +0000678- Large file support is now enabled on Win32 platforms as well as on
679 Win64. This means that, for example, you can use f.tell() and f.seek()
680 to manipulate files larger than 2 gigabytes (provided you have enough
681 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000682 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
683 filesize limit, and large file support makes no difference there.
684 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
685 NTFS has no practical limit on file size, and files of any size can be
686 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000687
Tim Petersbdee63f2001-09-02 03:40:59 +0000688- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000689 points to command.com (patch from Brian Quinlan).
690
Tim Petersedc99312001-08-22 21:36:50 +0000691
Tim Peters20f51a72001-07-21 02:31:40 +0000692What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000693Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000694===========================
695
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000696Build
697
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000698- Tim Peters developed a brand new Windows installer using Wise 8.1,
699 generously donated to us by Wise Solutions.
700
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000701- configure supports a new option --enable-unicode, with the values
702 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
703 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000704
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000705- A new configure option --enable-framework builds a Mac OS X framework,
706 which "make frameworkinstall" will install. This provides a starting
707 point for more mac-like functionality, join pythonmac-sig@python.org
708 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000709
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000710- The NeXT platform is no longer supported.
711
712- The `new' module is now statically linked.
713
Tim Peters0afb6092001-08-15 06:06:44 +0000714Tools
715
716- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000717 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000718 the module docstring for details.
719
Tim Peters20f51a72001-07-21 02:31:40 +0000720Tests
721
Tim Peters5e824c32001-08-12 22:25:01 +0000722- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000723 platforms, allowing to give clearer test result output. regrtest
724 also has optional --use/-u switch to run normally disabled tests
725 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000726
Tim Peters20f51a72001-07-21 02:31:40 +0000727- Several new tests in the standard test suite, with special thanks to
728 Nick Mathewson.
729
730Core
731
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000732- The floor division operator // has been added as outlined in PEP
733 238. The / operator still provides classic division (and will until
734 Python 3.0) unless "from __future__ import division" is included, in
735 which case the / operator will provide true division. The operator
736 module provides truediv() and floordiv() functions. Augmented
737 assignment variants are included, as are the equivalent overloadable
738 methods and C API methods. See the PEP for a full discussion:
739 <http://python.sf.net/peps/pep-0238.html>
740
Tim Peters6cd6a822001-08-17 22:11:27 +0000741- Future statements are now effective in simulated interactive shells
742 (like IDLE). This should "just work" by magic, but read Michael
743 Hudson's "Future statements in simulated shells" PEP 264 for full
744 details: <http://python.sf.net/peps/pep-0264.html>.
745
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000746- The type/class unification (PEP 252-253) was integrated into the
747 trunk and is not so tentative any more (the exact specification of
748 some features is still tentative). A lot of work has done on fixing
749 bugs and adding robustness and features (performance still has to
750 come a long way).
751
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000752- Warnings about a mismatch in the Python API during extension import
753 now use the Python warning framework (which makes it possible to
754 write filters for these warnings).
755
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000756- A function's __dict__ (aka func_dict) will now always be a
757 dictionary. It used to be possible to delete it or set it to None,
758 but now both actions raise TypeErrors. It is still legal to set it
759 to a dictionary object. Getting func.__dict__ before any attributes
760 have been assigned now returns an empty dictionary instead of None.
761
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000762- A new command line option, -E, was added which disables the use of
763 all environment variables, or at least those that are specifically
764 significant to Python. Usually those have a name starting with
765 "PYTHON". This was used to fix a problem where the tests fail if
766 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
767 older distribution.
768
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000769Library
770
Tim Peters5e824c32001-08-12 22:25:01 +0000771- New class Differ and new functions ndiff() and restore() in difflib.py.
772 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000773 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000774
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000775- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
776 value using the minimal quoting required for the value; more
777 reliable than using xml.sax.saxutils.escape() for attribute values.
778
779- Readline completion support for cmd.Cmd was added.
780
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000781- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
782
783- Added function threading.BoundedSemaphore()
784
785- Added Ka-Ping Yee's cgitb.py module.
786
787- The `new' module now exposes the CO_xxx flags.
788
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000789New platforms
790
791C API
792
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000793- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
794 which provide a cross-platform implementations for the
795 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
796 the standard sprintf() and vsprintf() C lib APIs, these versions
797 apply bounds checking on the used buffer which enhances protection
798 against buffer overruns.
799
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000800- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000801 and extensions using different Unicode widths is rendered next to
802 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000803 will result in an ImportError. Unicode extensions writers must make
804 sure to check the Unicode width compatibility in their extensions by
805 using at least one of the mangled Unicode APIs in the extension.
806
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000807- Two new flags METH_NOARGS and METH_O are available in method definition
808 tables to simplify implementation of methods with no arguments and a
809 single untyped argument. Calling such methods is more efficient than
810 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
811 deprecated.
812
Tim Petersc1731372001-08-04 08:12:36 +0000813Windows
814
815- "import module" now compiles module.pyw if it exists and nothing else
816 relevant is found.
817
Tim Peters20f51a72001-07-21 02:31:40 +0000818
Guido van Rossum55a78992001-07-17 17:22:32 +0000819What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +0000820Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +0000821===========================
822
823Core
Tim Petersa814db52001-05-14 07:05:58 +0000824
Tim Peters6d6c1a32001-08-02 04:15:00 +0000825- TENTATIVELY, a large amount of code implementing much of what's
826 described in PEP 252 (Making Types Look More Like Classes) and PEP
827 253 (Subtyping Built-in Types) was added. This will be released
828 with Python 2.2a1. Documentation will be provided separately
829 through http://www.python.org/2.2/. The purpose of releasing this
830 with Python 2.2a1 is to test backwards compatibility. It is
831 possible, though not likely, that a decision is made not to release
832 this code as part of 2.2 final, if any serious backwards
833 incompapatibilities are found during alpha testing that cannot be
834 repaired.
835
Guido van Rossum55a78992001-07-17 17:22:32 +0000836- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000837 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000838 more 'yield' statements. See PEP 255. Since this adds a new
839 keyword to the language, this feature must be enabled by including a
840 future statement: "from __future__ import generators" (see PEP 236).
841 Generators will become a standard feature in a future release
842 (probably 2.3). Without this future statement, 'yield' remains an
843 ordinary identifier, but a warning is issued each time it is used.
844 (These warnings currently don't conform to the warnings framework of
845 PEP 230; we intend to fix this in 2.2a2.)
846
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000847- The UTF-16 codec was modified to be more RFC compliant. It will now
848 only remove BOM characters at the start of the string and then
849 only if running in native mode (UTF-16-LE and -BE won't remove a
850 leading BMO character).
851
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000852- Strings now have a new method .decode() to complement the already
853 existing .encode() method. These two methods provide direct access
854 to the corresponding decoders and encoders of the registered codecs.
855
856 To enhance the usability of the .encode() method, the special
857 casing of Unicode object return values was dropped (Unicode objects
858 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000859
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000860 Both methods will now return whatever the codec in charge of the
861 requested encoding returns as object, e.g. Unicode codecs will
862 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
863 will return u"äöü"). This enables codec writer to create codecs
864 for various simple to use conversions.
865
866 New codecs were added to demonstrate these new features (the .encode()
867 and .decode() columns indicate the type of the returned objects):
868
869 Name | .encode() | .decode() | Description
870 ----------------------------------------------------------------------
871 uu | string | string | UU codec (e.g. for email)
872 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000873 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000874 zlib | string | string | zlib compression
875 hex | string | string | 2-byte hex codec
876 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
877
Mark Hammond2a0af792001-05-14 03:09:36 +0000878- Some operating systems now support the concept of a default Unicode
879 encoding for file system operations. Notably, Windows supports 'mbcs'
880 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000881 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000882 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000883
884 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000885 functions that return filenames (such as os.listdir()) to return Python
886 string objects pre-encoded using the default file system encoding for
887 the platform. As this encoding is likely to be different from Python's
888 default encoding, converting this name to a Unicode object before passing
889 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000890 would attempt to use its default encoding (generally ASCII) rather than
891 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000892
Tim Petersa814db52001-05-14 07:05:58 +0000893 In general, this change simply removes surprises when working with
894 Unicode and the file system, making these operations work as you expect,
895 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000896 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000897
Tim Peters61dff2b2001-05-08 15:43:37 +0000898- Float (and complex) literals in source code were evaluated to full
899 precision only when running from a .py file; the same code loaded from a
900 .pyc (or .pyo) file could suffer numeric differences starting at about the
901 12th significant decimal digit. For example, on a machine with IEEE-754
902 floating arithmetic,
903
904 x = 9007199254740992.0
905 print long(x)
906
907 printed 9007199254740992 if run directly from .py, but 9007199254740000
908 if from a compiled (.pyc or .pyo) file. This was due to marshal using
909 str(float) instead of repr(float) when building code objects. marshal
910 now uses repr(float) instead, which should reproduce floats to full
911 machine precision (assuming the platform C float<->string I/O conversion
912 functions are of good quality).
913
914 This may cause floating-point results to change in some cases, and
915 usually for the better, but may also cause numerically unstable
916 algorithms to break.
917
Tim Peters2f228e72001-05-13 00:19:31 +0000918- The implementation of dicts suffers fewer collisions, which has speed
919 benefits. However, the order in which dict entries appear in dict.keys(),
920 dict.values() and dict.items() may differ from previous releases for a
921 given dict. Nothing is defined about this order, so no program should
922 rely on it. Nevertheless, it's easy to write test cases that rely on the
923 order by accident, typically because of printing the str() or repr() of a
924 dict to an "expected results" file. See Lib/test/test_support.py's new
925 sortdict(dict) function for a simple way to display a dict in sorted
926 order.
927
Tim Peters7a3bfc32001-06-12 01:22:22 +0000928- Many other small changes to dicts were made, resulting in faster
929 operation along the most common code paths.
930
Guido van Rossum10315822001-05-01 20:54:30 +0000931- Dictionary objects now support the "in" operator: "x in dict" means
932 the same as dict.has_key(x).
933
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000934- The update() method of dictionaries now accepts generic mapping
935 objects. Specifically the argument object must support the .keys()
936 and __getitem__() methods. This allows you to say, for example,
937 {}.update(UserDict())
938
Guido van Rossum10315822001-05-01 20:54:30 +0000939- Iterators were added; this is a generalized way of providing values
940 to a for loop. See PEP 234. There's a new built-in function iter()
941 to return an iterator. There's a new protocol to get the next value
942 from an iterator using the next() method (in Python) or the
943 tp_iternext slot (in C). There's a new protocol to get iterators
944 using the __iter__() method (in Python) or the tp_iter slot (in C).
945 Iterating (i.e. a for loop) over a dictionary generates its keys.
946 Iterating over a file generates its lines.
947
Tim Petersf553f892001-05-01 20:45:31 +0000948- The following functions were generalized to work nicely with iterator
949 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000950 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000951 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
952 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000953 join() method of strings
954 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000955 'x in y' and 'x not in y' (PySequence_Contains() in C API)
956 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000957 right-hand side of assignment statements with multiple targets, such as
958 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000959
Tim Petersd85e1022001-05-11 21:51:48 +0000960- Accessing module attributes is significantly faster (for example,
961 random.random or os.path or yourPythonModule.yourAttribute).
962
Tim Peterse63415e2001-05-08 04:38:29 +0000963- Comparing dictionary objects via == and != is faster, and now works even
964 if the keys and values don't support comparisons other than ==.
965
Tim Peters95bf9392001-05-10 08:32:44 +0000966- Comparing dictionaries in ways other than == and != is slower: there were
967 insecurities in the dict comparison implementation that could cause Python
968 to crash if the element comparison routines for the dict keys and/or
969 values mutated the dicts. Making the code bulletproof slowed it down.
970
Tim Peterseb28ef22001-06-02 05:27:19 +0000971- Collisions in dicts are resolved via a new approach, which can help
972 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000973 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000974 faster now. Thanks to Christian Tismer for pointing out the cause and
975 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000976
Tim Peters52e155e2001-06-16 05:42:57 +0000977- repr() is much faster for large containers (dict, list, tuple).
978
979
Tim Petersa814db52001-05-14 07:05:58 +0000980Library
981
Fred Drake960fdf92001-07-20 18:38:26 +0000982- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
983 were added to the string module. These a locale-indenpendent
984 constants, unlike letters, lowercase, and uppercase. These are now
985 use in appropriate locations in the standard library.
986
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000987- The flags used in dlopen calls can now be configured using
988 sys.setdlopenflags and queried using sys.getdlopenflags.
989
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000990- Fredrik Lundh's xmlrpclib is now a standard library module. This
991 provides full client-side XML-RPC support. In addition,
992 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
993 one asyncore-based). Thanks to Eric Raymond for the documentation.
994
Guido van Rossum643d3912001-07-05 14:46:25 +0000995- The xrange() object is simplified: it no longer supports slicing,
996 repetition, comparisons, efficient 'in' checking, the tolist()
997 method, or the start, stop and step attributes. See PEP 260.
998
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000999- A new function fnmatch.filter to filter lists of file names was added.
1000
Barry Warsawffd674d2001-05-22 16:00:10 +00001001- calendar.py uses month and day names based on the current locale.
1002
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001003- strop is now *really* obsolete (this was announced before with 1.6),
1004 and issues DeprecationWarning when used (except for the four items
1005 that are still imported into string.py).
1006
Tim Petersa814db52001-05-14 07:05:58 +00001007- Cookie.py now sorts key+value pairs by key in output strings.
1008
1009- pprint.isrecursive(object) didn't correctly identify recursive objects.
1010 Now it does.
1011
Tim Peters95b3f782001-05-14 18:39:41 +00001012- pprint functions now much faster for large containers (tuple, list, dict).
1013
Tim Peters7b9542a2001-06-10 23:40:19 +00001014- New 'q' and 'Q' format codes in the struct module, corresponding to C
1015 types "long long" and "unsigned long long" (on Windows, __int64). In
1016 native mode, these can be used only when the platform C compiler supports
1017 these types (when HAVE_LONG_LONG is #define'd by the Python config
1018 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001019 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1020 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001021
Guido van Rossum83213cc2001-06-12 16:48:52 +00001022- The site module installs a new built-in function 'help' that invokes
1023 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1024 it displays a message reminding the user to use 'help()' or
1025 'help(object)'.
1026
Tim Petersa814db52001-05-14 07:05:58 +00001027Tests
1028
1029- New test_mutants.py runs dict comparisons where the key and value
1030 comparison operators mutute the dicts randomly during comparison. This
1031 rapidly causes Python to crash under earlier releases (not for the faint
1032 of heart: it can also cause Win9x to freeze or reboot!).
1033
1034- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001035 pprint.isreadable() return sensible results. Also verifies that simple
1036 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001037
Tim Peters4324aa32001-05-28 22:30:08 +00001038C API
1039
1040- Removed the unused last_is_sticky argument from the internal
1041 _PyTuple_Resize(). If this affects you, you were cheating.
1042
1043
Guido van Rossum55a78992001-07-17 17:22:32 +00001044======================================================================
1045
1046
Guido van Rossumffe13be2001-04-16 18:46:45 +00001047What's New in Python 2.1 (final)?
1048=================================
1049
1050We only changed a few things since the last release candidate, all in
1051Python library code:
1052
1053- A bug in the locale module was fixed that affected locales which
1054 define no grouping for numeric formatting.
1055
1056- A few bugs in the weakref module's implementations of weak
1057 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1058 and the test suite was updated to check for these bugs.
1059
1060- An old bug in the os.path.walk() function (introduced in Python
1061 2.0!) was fixed: a non-existent file would cause an exception
1062 instead of being ignored.
1063
1064- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1065 PyChecker.
1066
1067
Guido van Rossum5b08f132001-04-16 02:05:23 +00001068What's New in Python 2.1c2?
1069===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001070
Guido van Rossum5b08f132001-04-16 02:05:23 +00001071A flurry of small changes, and one showstopper fixed in the nick of
1072time made it necessary to release another release candidate. The list
1073here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001074
Guido van Rossum5b08f132001-04-16 02:05:23 +00001075Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001076
Guido van Rossum5b08f132001-04-16 02:05:23 +00001077- Tim discovered a nasty bug in the dictionary code, caused by
1078 PyDict_Next() calling dict_resize(), and the GC code's use of
1079 PyDict_Next() violating an assumption in dict_items(). This was
1080 fixed with considerable amounts of band-aid, but the net effect is a
1081 saner and more robust implementation.
1082
1083- Made a bunch of symbols static that were accidentally global.
1084
1085Build and Ports
1086
1087- The setup.py script didn't check for a new enough version of zlib
1088 (1.1.3 is needed). Now it does.
1089
1090- Changed "make clean" target to also remove shared libraries.
1091
1092- Added a more general warning about the SGI Irix optimizer to README.
1093
1094Library
1095
1096- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1097 omitted the slash between host and file.html.
1098
1099- The mailbox module's _Mailbox class contained a completely broken
1100 and undocumented seek() method. Ripped it out.
1101
1102- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1103 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1104
1105- Fixed a few last-minute bugs in unittest.
1106
1107Extensions
1108
1109- Reverted the patch to the OpenSSL code in socketmodule.c to support
1110 RAND_status() and the EGD, and the subsequent patch that tried to
1111 fix it for pre-0.9.5 versions; the problem with the patch is that on
1112 some systems it issues a warning whenever socket is imported, and
1113 that's unacceptable.
1114
1115Tests
1116
1117- Fixed the pickle tests to work with "import test.test_pickle".
1118
1119- Tweaked test_locale.py to actually run the test Windows.
1120
1121- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1122 not "wb" (which is not a valid mode at all).
1123
1124- Fix pstats browser crashes. Import readline if it exists to make
1125 the user interface nicer.
1126
1127- Add "import thread" to the top of test modules that import the
1128 threading module (test_asynchat and test_threadedtempfile). This
1129 prevents test failures caused by a broken threading module resulting
1130 from a previously caught failed import.
1131
1132- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1133 needed on some platforms (e.g. Solaris 8) when the tests are run
1134 twice in succession.
1135
1136- Skip rather than fail test_sunaudiodev if no audio device is found.
1137
1138
1139What's New in Python 2.1c1?
1140===========================
1141
1142This list was significantly updated when 2.1c2 was released; the 2.1c1
1143release didn't mention most changes that were actually part of 2.1c1:
1144
1145Legal
1146
1147- Copyright was assigned to the Python Software Foundation (PSF) and a
1148 PSF license (very similar to the CNRI license) was added.
1149
1150- The CNRI copyright notice was updated to include 2001.
1151
1152Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001153
Guido van Rossumc9932722001-04-12 02:31:27 +00001154- After a public outcry, assignment to __debug__ is no longer illegal;
1155 instead, a warning is issued. It will become illegal in 2.2.
1156
Guido van Rossum5b08f132001-04-16 02:05:23 +00001157- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1158 "%#x" now always prepends "0x", even if the value is zero.
1159
1160- Fixed some nits in the bytecode compiler.
1161
1162- Fixed core dumps when calling certain kinds of non-functions.
1163
1164- Fixed various core dumps caused by reference count bugs.
1165
1166Build and Ports
1167
1168- Use INSTALL_SCRIPT to install script files.
1169
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001170- New port: SCO Unixware 7, by Billy G. Allie.
1171
Guido van Rossum5b08f132001-04-16 02:05:23 +00001172- Updated RISCOS port.
1173
1174- Updated BeOS port and notes.
1175
1176- Various other porting problems resolved.
1177
1178Library
1179
1180- The TERMIOS and SOCKET modules are now truly obsolete and
1181 unnecessary. Their symbols are incorporated in the termios and
1182 socket modules.
1183
1184- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1185 better tests for pickling.
1186
1187- threading: make Condition.wait() robust against KeyboardInterrupt.
1188
1189- zipfile: add support to zipfile to support opening an archive
1190 represented by an open file rather than a file name. Fix bug where
1191 the archive was not properly closed. Fixed a bug in this bugfix
1192 where flush() was called for a read-only file.
1193
1194- imputil: added an uninstall() method to the ImportManager.
1195
1196- Canvas: fixed bugs in lower() and tkraise() methods.
1197
1198- SocketServer: API change (added overridable close_request() method)
1199 so that the TCP server can explicitly close the request.
1200
1201- pstats: Eric Raymond added a simple interactive statistics browser,
1202 invoked when the module is run as a script.
1203
1204- locale: fixed a problem in format().
1205
1206- webbrowser: made it work when the BROWSER environment variable has a
1207 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1208 KDE 2. Fixed some other nits.
1209
1210- unittest: changes to allow using a different exception than
1211 AssertionError, and added a few more function aliases. Some other
1212 small changes.
1213
1214- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1215
1216- asynchat: fixed a critical bug in asynchat that slipped through the
1217 2.1b2 release. Fixed another rare bug.
1218
1219- Fix some unqualified except: clauses (always a bad code example).
1220
1221XML
1222
1223- pyexpat: new API get_version_string().
1224
1225- Fixed some minidom bugs.
1226
1227Extensions
1228
1229- Fixed a core dump in _weakref. Removed the weakref.mapping()
1230 function (it adds nothing to the API).
1231
1232- Rationalized the use of header files in the readline module, to make
1233 it compile (albeit with some warnings) with the very recent readline
1234 4.2, without breaking for earlier versions.
1235
1236- Hopefully fixed a buffering problem in linuxaudiodev.
1237
1238- Attempted a fix to make the OpenSSL support in the socket module
1239 work again with pre-0.9.5 versions of OpenSSL.
1240
1241Tests
1242
1243- Added a test case for asynchat and asyncore.
1244
1245- Removed coupling between tests where one test failing could break
1246 another.
1247
1248Tools
1249
1250- Ping added an interactive help browser to pydoc, fixed some nits
1251 in the rest of the pydoc code, and added some features to his
1252 inspect module.
1253
1254- An updated python-mode.el version 4.1 which integrates Ken
1255 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1256 much nicer in XEmacs and Emacs. When stepping through your program
1257 with pdb, in either the shell window or the *Python* window, the
1258 source file and line will be tracked by an arrow. Very cool!
1259
1260- IDLE: syntax warnings in interactive mode are changed into errors.
1261
1262- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001263 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001264
1265- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001266
Barry Warsaw11e89c72001-04-11 20:37:57 +00001267
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001268What's New in Python 2.1 beta 2?
1269================================
1270
Guido van Rossum053ae352001-03-22 14:17:21 +00001271(Unlisted are many fixed bugs, more documentation, etc.)
1272
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001273Core language, builtins, and interpreter
1274
Guido van Rossum053ae352001-03-22 14:17:21 +00001275- The nested scopes work (enabled by "from __future__ import
1276 nested_scopes") is completed; in particular, the future now extends
1277 into code executed through exec, eval() and execfile(), and into the
1278 interactive interpreter.
1279
1280- When calling a base class method (e.g. BaseClass.__init__(self)),
1281 this is now allowed even if self is not strictly spoken a class
1282 instance (e.g. when using metaclasses or the Don Beaudry hook).
1283
1284- Slice objects are now comparable but not hashable; this prevents
1285 dict[:] from being accepted but meaningless.
1286
1287- Complex division is now calculated using less braindead algorithms.
1288 This doesn't change semantics except it's more likely to give useful
1289 results in extreme cases. Complex repr() now uses full precision
1290 like float repr().
1291
1292- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1293
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001294- It is illegal to assign to the name __debug__, which is set when the
1295 interpreter starts. It is effectively a compile-time constant.
1296
1297- A warning will be issued if a global statement for a variable
1298 follows a use or assignment of that variable.
1299
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001300Standard library
1301
Guido van Rossum053ae352001-03-22 14:17:21 +00001302- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1303 inspired by JUnit), is now part of the standard library. You now
1304 have a choice of two testing frameworks: unittest requires you to
1305 write testcases as separate code, doctest gathers them from
1306 docstrings. Both approaches have their advantages and
1307 disadvantages.
1308
1309- A new module Tix was added, which wraps the Tix extension library
1310 for Tk. With that module, it is not necessary to statically link
1311 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1312 require" command. See Demo/tix/.
1313
1314- tzparse.py is now obsolete.
1315
1316- In gzip.py, the seek() and tell() methods are removed -- they were
1317 non-functional anyway, and it's better if callers can test for their
1318 existence with hasattr().
1319
1320Python/C API
1321
1322- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1323 that's already in the dictionary during a PyDict_Next() iteration.
1324 This used to fail occasionally when a dictionary resize operation
1325 could be triggered that would rehash all the keys. All other
1326 modifications to the dictionary are still off-limits during a
1327 PyDict_Next() iteration!
1328
1329- New extended APIs related to passing compiler variables around.
1330
1331- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1332 implement isinstance() and issubclass().
1333
1334- Py_BuildValue() now has a "D" conversion to create a Python complex
1335 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001336
Fred Drake4e262a92001-03-22 18:26:47 +00001337- Extensions types which support weak references must now set the
1338 field allocated for the weak reference machinery to NULL themselves;
1339 this is done to avoid the cost of checking each object for having a
1340 weakly referencable type in PyObject_INIT(), since most types are
1341 not weakly referencable.
1342
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001343- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1344 free variables and cell variables to and from the frame's f_locals.
1345
1346- Variants of several functions defined in pythonrun.h have been added
1347 to support the nested_scopes future statement. The variants all end
1348 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1349 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1350 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001351 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001352
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001353Distutils
1354
1355- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1356 into the release tree.
1357
Tim Peters0e57abf2001-05-02 07:39:38 +00001358- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001359 (an uninstaller, more customization of the installer's display)
1360
1361- from Jack Jansen: added Mac-specific code to generate a dialog for
1362 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001363 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001364 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001365
1366- added 'platforms' and 'keywords' to the set of metadata that can be
1367 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001368
1369- applied patches from Jason Tishler to make the compiler class work with
1370 Cygwin.
1371
1372
Tim Peters2fe289a2001-03-01 22:19:38 +00001373What's New in Python 2.1 beta 1?
1374================================
Tim Petersd66595f2001-02-04 03:09:53 +00001375
1376Core language, builtins, and interpreter
1377
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001378- Following an outcry from the community about the amount of code
1379 broken by the nested scopes feature introduced in 2.1a2, we decided
1380 to make this feature optional, and to wait until Python 2.2 (or at
1381 least 6 months) to make it standard. The option can be enabled on a
1382 per-module basis by adding "from __future__ import nested_scopes" at
1383 the beginning of a module (before any other statements, but after
1384 comments and an optional docstring). See PEP 236 (Back to the
1385 __future__) for a description of the __future__ statement. PEP 227
1386 (Statically Nested Scopes) has been updated to reflect this change,
1387 and to clarify the semantics in a number of endcases.
1388
1389- The nested scopes code, when enabled, has been hardened, and most
1390 bugs and memory leaks in it have been fixed.
1391
1392- Compile-time warnings are now generated for a number of conditions
1393 that will break or change in meaning when nested scopes are enabled:
1394
1395 - Using "from...import *" or "exec" without in-clause in a function
1396 scope that also defines a lambda or nested function with one or
1397 more free (non-local) variables. The presence of the import* or
1398 bare exec makes it impossible for the compiler to determine the
1399 exact set of local variables in the outer scope, which makes it
1400 impossible to determine the bindings for free variables in the
1401 inner scope. To avoid the warning about import *, change it into
1402 an import of explicitly name object, or move the import* statement
1403 to the global scope; to avoid the warning about bare exec, use
1404 exec...in... (a good idea anyway -- there's a possibility that
1405 bare exec will be deprecated in the future).
1406
1407 - Use of a global variable in a nested scope with the same name as a
1408 local variable in a surrounding scope. This will change in
1409 meaning with nested scopes: the name in the inner scope will
1410 reference the variable in the outer scope rather than the global
1411 of the same name. To avoid the warning, either rename the outer
1412 variable, or use a global statement in the inner function.
1413
Neil Schemenauera35c6882001-02-27 04:45:05 +00001414- An optional object allocator has been included. This allocator is
1415 optimized for Python objects and should be faster and use less memory
1416 than the standard system allocator. It is not enabled by default
1417 because of possible thread safety problems. The allocator is only
1418 protected by the Python interpreter lock and it is possible that some
1419 extension modules require a thread safe allocator. The object
1420 allocator can be enabled by providing the "--with-pymalloc" option to
1421 configure.
1422
Tim Petersd66595f2001-02-04 03:09:53 +00001423Standard library
1424
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001425- pyexpat now detects the expat version if expat.h defines it. A
1426 number of additional handlers are provided, which are only available
1427 since expat 1.95. In addition, the methods SetParamEntityParsing and
1428 GetInputContext of Parser objects are available with 1.95.x
1429 only. Parser objects now provide the ordered_attributes and
1430 specified_attributes attributes. A new module expat.model was added,
1431 which offers a number of additional constants if 1.95.x is used.
1432
1433- xml.dom offers the new functions registerDOMImplementation and
1434 getDOMImplementation.
1435
1436- xml.dom.minidom offers a toprettyxml method. A number of DOM
1437 conformance issues have been resolved. In particular, Element now
1438 has an hasAttributes method, and the handling of namespaces was
1439 improved.
1440
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001441- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1442 getting information about live Python code, and pydoc.py, a module
1443 for interactively converting docstrings to HTML or text.
1444 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001445 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001446 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1447 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001448
Tim Peters1eff7962001-03-01 02:31:33 +00001449- New library module difflib.py, primarily packaging the SequenceMatcher
1450 class at the heart of the popular ndiff.py file-comparison tool.
1451
1452- doctest.py (a framework for verifying Python code examples in docstrings)
1453 is now part of the std library.
1454
Tim Petersd66595f2001-02-04 03:09:53 +00001455Windows changes
1456
Guido van Rossume3955a82001-03-02 14:05:59 +00001457- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1458 small GUI that lets you browse the module docstrings using your
1459 default web browser.
1460
Tim Peters1eff7962001-03-01 02:31:33 +00001461- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1462 Platforms) is implemented. See
1463
1464 http://python.sourceforge.net/peps/pep-0235.html
1465
1466 for full details, especially the "Current Lower-Left Semantics" section.
1467 The new Windows import rules are simpler than before:
1468
1469 A. If the PYTHONCASEOK environment variable exists, same as
1470 before: silently accept the first case-insensitive match of any
1471 kind; raise ImportError if none found.
1472
1473 B. Else search sys.path for the first case-sensitive match; raise
1474 ImportError if none found.
1475
1476 The same rules have been implented on other platforms with case-
1477 insensitive but case-preserving filesystems too (including Cygwin, and
1478 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001479
Tim Peters25a9ce32001-02-19 07:06:36 +00001480- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1481 what it's supposed to do (and does do under NT and 2000) via direct
1482 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001483 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001484 all Win9x systems before.
1485
Tim Peters1eff7962001-03-01 02:31:33 +00001486- Build: Subproject _test (effectively) renamed to _testcapi.
1487
Tim Peters2fe289a2001-03-01 22:19:38 +00001488New platforms
1489
1490- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1491 Thanks to Steven Majewski!
1492
1493- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1494 Tishler!
1495
Guido van Rossum9089b272001-03-02 06:49:50 +00001496- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1497 Schwertberger! See RISCOS/README for more information -- it seems
1498 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001499 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001500
Tim Peters25a9ce32001-02-19 07:06:36 +00001501
Tim Petersd7b5e882001-01-25 03:36:26 +00001502What's New in Python 2.1 alpha 2?
1503=================================
Tim Peters40ead762001-01-27 05:35:26 +00001504
Tim Petersd7b5e882001-01-25 03:36:26 +00001505Core language, builtins, and interpreter
1506
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001507- Scopes nest. If a name is used in a function or class, but is not
1508 local, the definition in the nearest enclosing function scope will
1509 be used. One consequence of this change is that lambda statements
1510 could reference variables in the namespaces where the lambda is
1511 defined. In some unusual cases, this change will break code.
1512
1513 In all previous version of Python, names were resolved in exactly
1514 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001515 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001516 function A is defined within a function B, the names bound in B are
1517 not visible in A. The new rules make names bound in B visible in A,
1518 unless A contains a name binding that hides the binding in B.
1519
1520 Section 4.1 of the reference manual describes the new scoping rules
1521 in detail. The test script in Lib/test/test_scope.py demonstrates
1522 some of the effects of the change.
1523
1524 The new rules will cause existing code to break if it defines nested
1525 functions where an outer function has local variables with the same
1526 name as globals or builtins used by the inner function. Example:
1527
1528 def munge(str):
1529 def helper(x):
1530 return str(x)
1531 if type(str) != type(''):
1532 str = helper(str)
1533 return str.strip()
1534
1535 Under the old rules, the name str in helper() is bound to the
1536 builtin function str(). Under the new rules, it will be bound to
1537 the argument named str and an error will occur when helper() is
1538 called.
1539
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001540- The compiler will report a SyntaxError if "from ... import *" occurs
1541 in a function or class scope. The language reference has documented
1542 that this case is illegal, but the compiler never checked for it.
1543 The recent introduction of nested scope makes the meaning of this
1544 form of name binding ambiguous. In a future release, the compiler
1545 may allow this form when there is no possibility of ambiguity.
1546
Tim Peters40ead762001-01-27 05:35:26 +00001547- repr(string) is easier to read, now using hex escapes instead of octal,
1548 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1549
1550 >>> "\texample \r\n" + chr(0) + chr(255)
1551 '\texample \r\n\x00\xff' # in 2.1
1552 '\011example \015\012\000\377' # in 2.0
1553
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001554- Functions are now compared and hashed by identity, not by value, since
1555 the func_code attribute is writable.
1556
Fred Drakefb9d7122001-02-01 20:00:40 +00001557- Weak references (PEP 205) have been added. This involves a few
1558 changes in the core, an extension module (_weakref), and a Python
1559 module (weakref). The weakref module is the public interface. It
1560 includes support for "explicit" weak references, proxy objects, and
1561 mappings with weakly held values.
1562
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001563- A 'continue' statement can now appear in a try block within the body
1564 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001565 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001566
Tim Petersd7b5e882001-01-25 03:36:26 +00001567Standard library
1568
Barry Warsaw30dbd142001-01-31 22:14:01 +00001569- mailbox.py now has a new class, PortableUnixMailbox which is
1570 identical to UnixMailbox but uses a more portable scheme for
1571 determining From_ separators. Also, the constructors for all the
1572 classes in this module have a new optional `factory' argument, which
1573 is a callable used when new message classes must be instantiated by
1574 the next() method.
1575
Tim Petersd7b5e882001-01-25 03:36:26 +00001576- random.py is now self-contained, and offers all the functionality of
1577 the now-deprecated whrandom.py. See the docs for details. random.py
1578 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001579 and restoring the internal state of the generator; and jumpahead(n),
1580 for quickly forcing the internal state to be the same as if n calls to
1581 random() had been made. The latter is particularly useful for multi-
1582 threaded programs, creating one instance of the random.Random() class for
1583 each thread, then using .jumpahead() to force each instance to use a
1584 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001585
Tim Peters0de88fc2001-02-01 04:59:18 +00001586- random.py's seed() function is new. For bit-for-bit compatibility with
1587 prior releases, use the whseed function instead. The new seed function
1588 addresses two problems: (1) The old function couldn't produce more than
1589 about 2**24 distinct internal states; the new one about 2**45 (the best
1590 that can be done in the Wichmann-Hill generator). (2) The old function
1591 sometimes produced identical internal states when passed distinct
1592 integers, and there was no simple way to predict when that would happen;
1593 the new one guarantees to produce distinct internal states for all
1594 arguments in [0, 27814431486576L).
1595
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001596- The socket module now supports raw packets on Linux. The socket
1597 family is AF_PACKET.
1598
Tim Peters9ea17ac2001-02-02 05:57:15 +00001599- test_capi.py is a start at running tests of the Python C API. The tests
1600 are implemented by the new Modules/_testmodule.c.
1601
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001602- A new extension module, _symtable, provides provisional access to the
1603 internal symbol table used by the Python compiler. A higher-level
1604 interface will be added on top of _symtable in a future release.
1605
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001606- Removed the obsolete soundex module.
1607
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001608- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1609 the isSameNode method; NamedNodeMap the get method.
1610
1611- xml.sax.expatreader supports the lexical handler property; it
1612 generates comment, startCDATA, and endCDATA events.
1613
Tim Petersee826f82001-01-31 19:39:44 +00001614Windows changes
1615
1616- Build procedure: the zlib project is built in a different way that
1617 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001618 the zlib binary used. See PCbuild\readme.txt for details. Your old
1619 zlib-related directories can be deleted; you'll need to download fresh
1620 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001621
Tim Peters9ea17ac2001-02-02 05:57:15 +00001622- Build: New subproject _test for the benefit of test_capi.py (see above).
1623
Tim Petersb16c56f2001-02-02 21:24:51 +00001624- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1625 interface to some Python compiler internals).
1626
1627- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001628 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001629
Tim Petersa3a3a032000-11-30 05:22:44 +00001630What's New in Python 2.1 alpha 1?
1631=================================
1632
1633Core language, builtins, and interpreter
1634
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001635- There is a new Unicode companion to the PyObject_Str() API
1636 called PyObject_Unicode(). It behaves in the same way as the
1637 former, but assures that the returned value is an Unicode object
1638 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001639
Guido van Rossumf98eda02001-01-17 15:54:45 +00001640- The comparison operators support "rich comparison overloading" (PEP
1641 207). C extension types can provide a rich comparison function in
1642 the new tp_richcompare slot in the type object. The cmp() function
1643 and the C function PyObject_Compare() first try the new rich
1644 comparison operators before trying the old 3-way comparison. There
1645 is also a new C API PyObject_RichCompare() (which also falls back on
1646 the old 3-way comparison, but does not constrain the outcome of the
1647 rich comparison to a Boolean result).
1648
1649 The rich comparison function takes two objects (at least one of
1650 which is guaranteed to have the type that provided the function) and
1651 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1652 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1653 object, which may be NotImplemented (in which case the tp_compare
1654 slot function is used as a fallback, if defined).
1655
1656 Classes can overload individual comparison operators by defining one
1657 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001658 __ge__. There are no explicit "reflected argument" versions of
1659 these; instead, __lt__ and __gt__ are each other's reflection,
1660 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1661 reflection (similar at the C level). No other implications are
1662 made; in particular, Python does not assume that == is the Boolean
1663 inverse of !=, or that < is the Boolean inverse of >=. This makes
1664 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001665
1666 Classes or types that want to implement (in)equality tests but not
1667 the ordering operators (i.e. unordered types) should implement ==
1668 and !=, and raise an error for the ordering operators.
1669
Guido van Rossuma88479f2001-01-18 14:28:08 +00001670 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001671 Boolean; e.g. a matrix type might want to return a matrix of bits
1672 for A < B, giving elementwise comparisons. Such types should ensure
1673 that any interpretation of their value in a Boolean context raises
1674 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1675 at the C level) to always raise an exception.
1676
Guido van Rossuma88479f2001-01-18 14:28:08 +00001677- Complex numbers use rich comparisons to define == and != but raise
1678 an exception for <, <=, > and >=. Unfortunately, this also means
1679 that cmp() of two complex numbers raises an exception when the two
1680 numbers differ. Since it is not mathematically meaningful to compare
1681 complex numbers except for equality, I hope that this doesn't break
1682 too much code.
1683
Tim Peters3389f192001-02-18 08:48:49 +00001684- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001685 not defined by the language, other than that it's arbitrary but
1686 consistent (see the Reference Manual). An implementation detail changed
1687 in 2.1a1 such that None now compares less than any other object. Code
1688 relying on this new behavior (like code that relied on the previous
1689 behavior) does so at its own risk.
1690
Barry Warsaw573b5412001-01-15 20:43:18 +00001691- Functions and methods now support getting and setting arbitrarily
1692 named attributes (PEP 232). Functions have a new __dict__
1693 (a.k.a. func_dict) which hold the function attributes. Methods get
1694 and set attributes on their underlying im_func. It is a TypeError
1695 to set an attribute on a bound method.
1696
Guido van Rossum051e3352001-01-15 19:11:10 +00001697- The xrange() object implementation has been improved so that
1698 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1699 limitation that in this case len(xrange(sys.maxint)) can't be
1700 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1701 work fine as long as the index i doesn't actually reach 2**31.
1702 (Python uses regular ints for sequence and string indices; fixing
1703 that is much more work.)
1704
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001705- Two changes to from...import:
1706
Guido van Rossumba381232001-02-03 15:06:40 +00001707 1) "from M import X" now works even if (after loading module M)
1708 sys.modules['M'] is not a real module; it's basically a getattr()
1709 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001710
1711 2) "from M import *" now looks for M.__all__ to decide which names to
1712 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1713 filters out names starting with '_' as before. Whether or not
1714 __all__ exists, there's no restriction on the type of M.
1715
Guido van Rossumf61f1662001-01-10 20:13:55 +00001716- File objects have a new method, xreadlines(). This is the fastest
1717 way to iterate over all lines in a file:
1718
1719 for line in file.xreadlines():
1720 ...do something to line...
1721
1722 See the xreadlines module (mentioned below) for how to do this for
1723 other file-like objects.
1724
1725- Even if you don't use file.xreadlines(), you may expect a speedup on
1726 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001727 quite a bit in platform-specific ways: on systems (like Linux) that
1728 support flockfile(), getc_unlocked(), and funlockfile(), those are
1729 used by default. On systems (like Windows) without getc_unlocked(),
1730 a complicated (but still thread-safe) method using fgets() is used by
1731 default.
1732
Tim Petersd52269b2001-01-25 06:23:18 +00001733 You can force use of the fgets() method by #define'ing
1734 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001735 getc_unlocked()).
1736
Tim Petersd52269b2001-01-25 06:23:18 +00001737 You can force fgets() not to be used by #define'ing
1738 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001739 test_bufio.py fails -- and let us know if it does!).
1740
1741- In addition, the fileinput module, while still slower than the other
1742 methods on most platforms, has been sped up too, by using
1743 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001744
1745- Support for run-time warnings has been added, including a new
1746 command line option (-W) to specify the disposition of warnings.
1747 See the description of the warnings module below.
1748
1749- Extensive changes have been made to the coercion code. This mostly
1750 affects extension modules (which can now implement mixed-type
1751 numerical operators without having to use coercion), but
1752 occasionally, in boundary cases the coercion semantics have changed
1753 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001754 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001755 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001756 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001757
Guido van Rossumf98eda02001-01-17 15:54:45 +00001758- In connection with the coercion changes, a new built-in singleton
1759 object, NotImplemented is defined. This can be returned for
1760 operations that wish to indicate they are not implemented for a
1761 particular combination of arguments. From C, this is
1762 Py_NotImplemented.
1763
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001764- The interpreter accepts now bytecode files on the command line even
1765 if they do not have a .pyc or .pyo extension. On Linux, after executing
1766
Martin v. Löwise214baa2001-02-04 22:37:56 +00001767import imp,sys,string
1768magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1769reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1770open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001771
1772 any byte code file can be used as an executable (i.e. as an argument
1773 to execve(2)).
1774
Tim Peters9940b802000-12-01 07:59:35 +00001775- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001776 character. In 1.6 and earlier, they never produced a sign,
1777 and raised an error if the value of the long was too large
1778 to fit in a Python int. In 2.0, they produced a sign if and
1779 only if too large to fit in an int. This was inconsistent
1780 across platforms (because the size of an int varies across
1781 platforms), and inconsistent with hex() and oct(). Example:
1782
1783 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001784 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001785 'ffffffbe' # in 2.0 and before, on 32-bit machines
1786 >>> hex(-0x42L)
1787 '-0x42L' # in all versions of Python
1788
Tim Peters9940b802000-12-01 07:59:35 +00001789 The behavior of %d formats for negative Python longs remains
1790 the same as in 2.0 (although in 1.6 and before, they raised
1791 an error if the long didn't fit in a Python int).
1792
1793 %u formats don't make sense for Python longs, but are allowed
1794 and treated the same as %d in 2.1. In 2.0, a negative long
1795 formatted via %u produced a sign if and only if too large to
1796 fit in an int. In 1.6 and earlier, a negative long formatted
1797 via %u raised an error if it was too big to fit in an int.
1798
Guido van Rossum3661d392000-12-12 22:10:31 +00001799- Dictionary objects have an odd new method, popitem(). This removes
1800 an arbitrary item from the dictionary and returns it (in the form of
1801 a (key, value) pair). This can be useful for algorithms that use a
1802 dictionary as a bag of "to do" items and repeatedly need to pick one
1803 item. Such algorithms normally end up running in quadratic time;
1804 using popitem() they can usually be made to run in linear time.
1805
Tim Peters36cdad12000-12-29 02:06:45 +00001806Standard library
1807
Thomas Woutersfe385252001-01-19 23:16:56 +00001808- In the time module, the time argument to the functions strftime,
1809 localtime, gmtime, asctime and ctime is now optional, defaulting to
1810 the current time (in the local timezone).
1811
Guido van Rossumda91f222001-01-15 16:36:08 +00001812- The ftplib module now defaults to passive mode, which is deemed a
1813 more useful default given that clients are often inside firewalls
1814 these days. Note that this could break if ftplib is used to connect
1815 to a *server* that is inside a firewall, from outside; this is
1816 expected to be a very rare situation. To fix that, you can call
1817 ftp.set_pasv(0).
1818
Martin v. Löwis10a27872001-01-13 09:54:41 +00001819- The module site now treats .pth files not only for path configuration,
1820 but also supports extensions to the initialization code: Lines starting
1821 with import are executed.
1822
Guido van Rossumf61f1662001-01-10 20:13:55 +00001823- There's a new module, warnings, which implements a mechanism for
1824 issuing and filtering warnings. There are some new built-in
1825 exceptions that serve as warning categories, and a new command line
1826 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1827 turns warnings into errors). warnings.warn(message[, category])
1828 issues a warning message; this can also be called from C as
1829 PyErr_Warn(category, message).
1830
1831- A new module xreadlines was added. This exports a single factory
1832 function, xreadlines(). The intention is that this code is the
1833 absolutely fastest way to iterate over all lines in an open
1834 file(-like) object:
1835
1836 import xreadlines
1837 for line in xreadlines.xreadlines(file):
1838 ...do something to line...
1839
1840 This is equivalent to the previous the speed record holder using
1841 file.readlines(sizehint). Note that if file is a real file object
1842 (as opposed to a file-like object), this is equivalent:
1843
1844 for line in file.xreadlines():
1845 ...do something to line...
1846
Tim Peters36cdad12000-12-29 02:06:45 +00001847- The bisect module has new functions bisect_left, insort_left,
1848 bisect_right and insort_right. The old names bisect and insort
1849 are now aliases for bisect_right and insort_right. XXX_right
1850 and XXX_left methods differ in what happens when the new element
1851 compares equal to one or more elements already in the list: the
1852 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001853 right. Code that doesn't care where equal elements end up should
1854 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001855
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001856- The new curses.panel module wraps the panel library that forms part
1857 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1858
Guido van Rossumf61f1662001-01-10 20:13:55 +00001859- The SocketServer module now sets the allow_reuse_address flag by
1860 default in the TCPServer class.
1861
1862- A new function, sys._getframe(), returns the stack frame pointer of
1863 the caller. This is intended only as a building block for
1864 higher-level mechanisms such as string interpolation.
1865
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001866- The pyexpat module supports a number of new handlers, which are
1867 available only in expat 1.2. If invocation of a callback fails, it
1868 will report an additional frame in the traceback. Parser objects
1869 participate now in garbage collection. If expat reports an unknown
1870 encoding, pyexpat will try to use a Python codec; that works only
1871 for single-byte charsets. The parser type objects is exposed as
1872 XMLParserObject.
1873
1874- xml.dom now offers standard definitions for symbolic node type and
1875 exception code constants, and a hierarchy of DOM exceptions. minidom
1876 was adjusted to use them.
1877
1878- The conformance of xml.dom.minidom to the DOM specification was
1879 improved. It detects a number of additional error cases; the
1880 previous/next relationship works even when the tree is modified;
1881 Node supports the normalize() method; NamedNodeMap, DocumentType and
1882 DOMImplementation classes were added; Element supports the
1883 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1884 method.
1885
Guido van Rossumf61f1662001-01-10 20:13:55 +00001886Build issues
1887
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001888- For Unix (and Unix-compatible) builds, configuration and building of
1889 extension modules is now greatly automated. Rather than having to
1890 edit the Modules/Setup file to indicate which modules should be
1891 built and where their include files and libraries are, a
1892 distutils-based setup.py script now takes care of building most
1893 extension modules. All extension modules built this way are built
1894 as shared libraries. Only a few modules that must be linked
1895 statically are still listed in the Setup file; you won't need to
1896 edit their configuration.
1897
1898- Python should now build out of the box on Cygwin. If it doesn't,
1899 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001900
1901- Python now always uses its own (renamed) implementation of getopt()
1902 -- there's too much variation among C library getopt()
1903 implementations.
1904
1905- C++ compilers are better supported; the CXX macro is always set to a
1906 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001907
Tim Petersd92dfe02000-12-12 01:18:41 +00001908Windows changes
1909
1910- select module: By default under Windows, a select() call
1911 can specify no more than 64 sockets. Python now boosts
1912 this Microsoft default to 512. If you need even more than
1913 that, see the MS docs (you'll need to #define FD_SETSIZE
1914 and recompile Python from source).
1915
Guido van Rossumf61f1662001-01-10 20:13:55 +00001916- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1917 subdirectory is no more!
1918
Tim Petersa3a3a032000-11-30 05:22:44 +00001919
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001920What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001921=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001922
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001923Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001924changes are in the file HISTORY. If you are making the jump directly
1925from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1926HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001927
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001928Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1929the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1930http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001931
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001932--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001933
1934======================================================================
1935
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001936What's new in 2.0 (since release candidate 1)?
1937==============================================
1938
1939Standard library
1940
1941- The copy_reg module was modified to clarify its intended use: to
1942 register pickle support for extension types, not for classes.
1943 pickle() will raise a TypeError if it is passed a class.
1944
1945- Fixed a bug in gettext's "normalize and expand" code that prevented
1946 it from finding an existing .mo file.
1947
1948- Restored support for HTTP/0.9 servers in httplib.
1949
Tim Peters989b7b92000-10-16 20:24:53 +00001950- The math module was changed to stop raising OverflowError in case of
1951 underflow, and return 0 instead in underflow cases. Whether Python
1952 used to raise OverflowError in case of underflow was platform-
1953 dependent (it did when the platform math library set errno to ERANGE
1954 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001955
1956- Fixed a bug in StringIO that occurred when the file position was not
1957 at the end of the file and write() was called with enough data to
1958 extend past the end of the file.
1959
1960- Fixed a bug that caused Tkinter error messages to get lost on
1961 Windows. The bug was fixed by replacing direct use of
1962 interp->result with Tcl_GetStringResult(interp).
1963
1964- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1965 redirect response.
1966
1967- Several changes were made to distutils: Some debugging code was
1968 removed from util. Fixed the installer used when an external zip
1969 program (like WinZip) is not found; the source code for this
1970 installer is in Misc/distutils. check_lib() was modified to behave
1971 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1972 test for whether installed modules are on sys.path was changed to
1973 use both normcase() and normpath().
1974
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001975- Several minor bugs were fixed in the xml package (the minidom,
1976 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001977
1978- The regression test driver (regrtest.py) behavior when invoked with
1979 -l changed: It now reports a count of objects that are recognized as
1980 garbage but not freed by the garbage collector.
1981
Tim Peters989b7b92000-10-16 20:24:53 +00001982- The regression test for the math module was changed to test
1983 exceptional behavior when the test is run in verbose mode. Python
1984 cannot yet guarantee consistent exception behavior across platforms,
1985 so the exception part of test_math is run only in verbose mode, and
1986 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001987
1988Internals
1989
1990- PyOS_CheckStack() has been disabled on Win64, where it caused
1991 test_sre to fail.
1992
1993Build issues
1994
1995- Changed compiler flags, so that gcc is always invoked with -Wall and
1996 -Wstrict-prototypes. Users compiling Python with GCC should see
1997 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001998 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001999 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002000
Tim Petersa3a3a032000-11-30 05:22:44 +00002001- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002002
2003Tools and other miscellany
2004
2005- The compiler in Tools/compiler was updated to support the new
2006 language features introduced in 2.0: extended print statement, list
2007 comprehensions, and augmented assignments. The new compiler should
2008 also be backwards compatible with Python 1.5.2; the compiler will
2009 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002010 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002011
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002012What's new in 2.0 release candidate 1 (since beta 2)?
2013=====================================================
2014
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002015What is release candidate 1?
2016
2017We believe that release candidate 1 will fix all known bugs that we
2018intend to fix for the 2.0 final release. This release should be a bit
2019more stable than the previous betas. We would like to see even more
2020widespread testing before the final release, so we are producing this
2021release candidate. The final release will be exactly the same unless
2022any show-stopping (or brown bag) bugs are found by testers of the
2023release candidate.
2024
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002025All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002026to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002027
2028Core language, builtins, and interpreter
2029
2030- A bug that caused crashes when __coerce__ was used with augmented
2031 assignment, e.g. +=, was fixed.
2032
2033- Raise ZeroDivisionError when raising zero to a negative number,
2034 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2035 power operator and the result of math.pow(0.0, -2.0) will vary by
2036 platform. On Linux, it raises a ValueError.
2037
2038- A bug in Unicode string interpolation was fixed that occasionally
2039 caused errors with formats including "%%". For example, the
2040 following expression "%% %s" % u"abc" no longer raises a TypeError.
2041
2042- Compilation of deeply nested expressions raises MemoryError instead
2043 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2044
2045- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2046 rendering them useless. They are now written in binary mode again.
2047
2048Standard library
2049
2050- Keyword arguments are now accepted for most pattern and match object
2051 methods in SRE, the standard regular expression engine.
2052
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002053- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002054 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002055
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002056- Several bugs in the Unicode handling and error handling in _tkinter
2057 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002058
2059- Fix memory management errors in Merge() and Tkapp_Call() routines.
2060
2061- Several changes were made to cStringIO to make it compatible with
2062 the file-like object interface and with StringIO. If operations are
2063 performed on a closed object, an exception is raised. The truncate
2064 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002065 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002066
2067- There were many changes made to the linuxaudiodev module and its
2068 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002069 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002070
2071 Note that this module is named poorly, because it should work
2072 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002073 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002074
2075 The module now raises exceptions when errors occur instead of
2076 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2077 audio) and defines a getptr() method that calls the
2078 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2079
2080- The library_version attribute, introduced in an earlier beta, was
2081 removed because it can not be supported with early versions of the C
2082 readline library, which provides no way to determine the version at
2083 compile-time.
2084
2085- The binascii module is now enabled on Win64.
2086
Tim Peters46446d62000-10-09 21:19:31 +00002087- tokenize.py no longer suffers "recursion depth" errors when parsing
2088 programs with very long string literals.
2089
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002090Internals
2091
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002092- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002093 which is called when the interpreter starts up to determine where
2094 the standard library is installed. These vulnerabilities affect all
2095 previous versions of Python and can be exploited by setting very
2096 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2097 setuid Python script, although use of the wrapper in
2098 Misc/setuid-prog.c will eliminate the vulnerability.
2099
2100- Fixed garbage collection bugs in instance creation that were
2101 triggered when errors occurred during initialization. The solution,
2102 applied in cPickle and in PyInstance_New(), is to call
2103 PyObject_GC_Init() after the initialization of the object's
2104 container attributes is complete.
2105
2106- pyexpat adds definitions of PyModule_AddStringConstant and
2107 PyModule_AddObject if the Python version is less than 2.0, which
2108 provides compatibility with PyXML on Python 1.5.2.
2109
2110- If the platform has a bogus definition for LONG_BIT (the number of
2111 bits in a long), an error will be reported at compile time.
2112
2113- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2114 collection crashes and possibly other, unreported crashes.
2115
2116- Fixed a memory leak in _PyUnicode_Fini().
2117
2118Build issues
2119
2120- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002121 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002122 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002123
2124- The mmap.PAGESIZE constant is now initialized using sysconf when
2125 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2126
2127- The md5 file should now compile on all platforms.
2128
2129- The select module now compiles on platforms that do not define
2130 POLLRDNORM and related constants.
2131
2132- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002133 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002134
Jeremy Hylton10921202000-10-09 18:34:12 +00002135- BeOS: A number of changes were made to the build and installation
2136 process. ar-fake now operates on a directory of object files.
2137 dl_export.h is gone, and its macros now appear on the mwcc command
2138 line during build on PPC BeOS.
2139
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002140- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002141 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002142
2143- Cygwin: Support for shared libraries, Tkinter, and sockets.
2144
2145- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2146
2147Tools and other miscellany
2148
2149- Removed debugging prints from main used with freeze.
2150
Tim Peters46446d62000-10-09 21:19:31 +00002151- IDLE auto-indent no longer crashes when it encounters Unicode
2152 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002153
2154What's new in 2.0 beta 2 (since beta 1)?
2155========================================
2156
2157Core language, builtins, and interpreter
2158
Tim Peters482c0212000-09-26 06:33:09 +00002159- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002160 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002161
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002162- Add -h and -V command line options to print the usage message and
2163 Python version number and exit immediately.
2164
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002165- eval() and exec accept Unicode objects as code parameters.
2166
2167- getattr() and setattr() now also accept Unicode objects for the
2168 attribute name, which are converted to strings using the default
2169 encoding before lookup.
2170
2171- Multiplication on string and Unicode now does proper bounds
2172 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2173 string is too long."
2174
2175- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002176 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002177
Jeremy Hylton1b618592000-09-26 05:32:36 +00002178
2179Standard library and extensions
2180
Guido van Rossum5b08f132001-04-16 02:05:23 +00002181- socket module: the OpenSSL code now adds support for RAND_status()
2182 and EGD (Entropy Gathering Device).
2183
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002184- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002185 argument checking; it still takes no arguments.
2186
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002187- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002188
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002189- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002190
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002191- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002192
2193- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002194 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002195
2196- copy: Copy Unicode objects atomically.
2197
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002198- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002199
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002200- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002201
Fred Drake67233bc2000-09-26 16:40:27 +00002202- dbm: Add get() and setdefault() methods to dbm object. Add constant
2203 `library' to module that names the library used. Added doc strings
2204 and method names to error messages. Uses configure to determine
2205 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2206 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002207
2208- distutils: Update to version 0.9.3.
2209
2210- dl: Add several dl.RTLD_ constants.
2211
2212- fpectl: Now supported on FreeBSD.
2213
2214- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2215 found by the collector will be saved in gc.garbage. This is useful
2216 for debugging a program that creates reference cycles.
2217
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002218- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002219 of HTTP class. Do not close socket on zero-length response. Do not
2220 crash when server sends invalid content-length header.
2221
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002222- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002223
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002224- marshal: When reading a short, sign-extend on platforms where shorts
2225 are bigger than 16 bits. When reading a long, repair the unportable
2226 sign extension that was being done for 64-bit machines. (It assumed
2227 that signed right shift sign-extends.)
2228
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002229- operator: Add contains(), invert(), __invert__() as aliases for
2230 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002231
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002232- os: Add support for popen2() and popen3() on all platforms where
2233 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002234
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002235- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002236 clicking on a file in Explorer (or passing the file name to the
2237 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002238
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002239- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002240 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002241
2242- pickle: Now raises ValueError when an invalid pickle that contains
2243 a non-string repr where a string repr was expected. This behavior
2244 matches cPickle.
2245
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002246- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002247
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002248- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002249
2250- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002251 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002252 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002253
2254- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002255 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002256
2257- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002258 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002259 few cycles during startup since the first call to
2260 setdefaultencoding() will initialize the codec registry and the
2261 encodings package.
2262
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002263- socket: Support for size hint in readlines() method of object returned
2264 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002265
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002266- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002267 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002268 is followed by whitespace.
2269
Tim Petersa3a3a032000-11-30 05:22:44 +00002270- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002271
2272- struct: Check ranges for bytes and shorts.
2273
2274- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002275 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002276
2277- Tkinter: Image objects are now guaranteed to have unique ids. Set
2278 event.delta to zero if Tk version doesn't support mousewheel.
2279 Removed some debugging prints.
2280
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002281- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002282
Fred Drake67233bc2000-09-26 16:40:27 +00002283- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002284 which works around a bug in Norton AntiVirus 2000 that leads directly
2285 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002286
2287- xml: New version detection code allows PyXML to override standard
2288 XML package if PyXML version is greater than 0.6.1.
2289
Fred Drake64bb3802000-09-26 16:21:35 +00002290- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2291 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2292 tree only for nodes which are sufficiently interesting to a specific
2293 application. Does not provide the HTML-specific extensions. Still
2294 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002295
Fred Drake64bb3802000-09-26 16:21:35 +00002296- xml.sax: SAX 2 support for Python, including all the handler
2297 interfaces needed to process XML 1.0 compliant XML. Some
2298 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002299
Fred Drake64bb3802000-09-26 16:21:35 +00002300- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2301 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002302
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002303
Jeremy Hylton1b618592000-09-26 05:32:36 +00002304C API
2305
2306- Add three new convenience functions for module initialization --
2307 PyModule_AddObject(), PyModule_AddIntConstant(), and
2308 PyModule_AddStringConstant().
2309
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002310- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002311 removed and add #error to Python.h if NULL isn't defined after
2312 #include of stdio.h.
2313
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002314- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002315 backwards compatibility (at the source level) with old extensions.
2316
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002317- A wrapper API was added for signal() and sigaction(). Instead of
2318 either function, always use PyOS_getsig() to get a signal handler
2319 and PyOS_setsig() to set one. A new convenience typedef
2320 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002321
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002322- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002323 internal data buffer and size of a string object -- or the default
2324 encoded version of a Unicode object.
2325
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002326- PyString_Size() and PyString_AsString() accept Unicode objects.
2327
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002328- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002329 exists). INT_MAX and LONG_MAX will always be defined, even if
2330 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002331
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002332- PyFloat_FromString takes a second argument, pend, that was
2333 effectively useless. It is now officially useless but preserved for
2334 backwards compatibility. If the pend argument is not NULL, *pend is
2335 set to NULL.
2336
2337- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2338 for the attribute name. See note on getattr() above.
2339
2340- A few bug fixes to argument processing for Unicode.
2341 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2342 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2343 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002344 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002345
2346- Py_BuildValue accepts B format (for bgen-generated code).
2347
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002348
Jeremy Hylton1b618592000-09-26 05:32:36 +00002349Internals
2350
2351- On Unix, fix code for finding Python installation directory so that
2352 it works when argv[0] is a relative path.
2353
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002354- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002355 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002356 rather than by generating a copy of the object.
2357
Tim Peters482c0212000-09-26 06:33:09 +00002358- Several of the internal Unicode tables are much smaller now, and
2359 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002360
Jeremy Hylton97693b02000-09-26 17:42:51 +00002361- In the garbage collector: Fixed bug in collection of tuples. Fixed
2362 bug that caused some instances to be removed from the container set
2363 while they were still live. Fixed parsing in gc.set_debug() for
2364 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002365
2366- Fixed refcount problem in instance deallocation that only occurred
2367 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2368
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002369- On Windows, getpythonregpath is now protected against null data in
2370 registry key.
2371
2372- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002373 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002374
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002375
Jeremy Hylton1b618592000-09-26 05:32:36 +00002376Build and platform-specific issues
2377
2378- Better support of GNU Pth via --with-pth configure option.
2379
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002380- Python/C API now properly exposed to dynamically-loaded extension
2381 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002382
2383- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2384 Don't define MS_SYNC to be zero when it is undefined. Added missing
2385 prototypes in posixmodule.c.
2386
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002387- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002388 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002389
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002390- Fix largefile support on older NetBSD systems and OpenBSD by adding
2391 define for TELL64.
2392
2393
2394Tools and other miscellany
2395
2396- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2397
2398- freeze: The modulefinder now works with 2.0 opcodes.
2399
Tim Petersa3a3a032000-11-30 05:22:44 +00002400- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002401 Move hackery of sys.argv until after the Tk instance has been
2402 created, which allows the application-specific Tkinter
2403 initialization to be executed if present; also pass an explicit
2404 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002405
Jeremy Hylton1b618592000-09-26 05:32:36 +00002406
2407What's new in 2.0 beta 1?
2408=========================
2409
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002410Source Incompatibilities
2411------------------------
2412
2413None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2414such as single-argument append(), connect() and bind(), and changes to
2415str(long) and repr(float).
2416
2417
2418Binary Incompatibilities
2419------------------------
2420
2421- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2422with Python 2.0; these extensions will have to be rebuilt for Python
24232.0.
2424
2425- On Windows, attempting to import a third party extension built for
2426Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2427can do about this. Check your PYTHONPATH environment variable!
2428
2429- Python bytecode files (*.pyc and *.pyo) are not compatible between
2430releases.
2431
2432
2433Overview of Changes Since 1.6
2434-----------------------------
2435
2436There are many new modules (including brand new XML support through
2437the xml package, and i18n support through the gettext module); a list
2438of all new modules is included below. Lots of bugs have been fixed.
2439
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002440The process for making major new changes to the language has changed
2441since Python 1.6. Enhancements must now be documented by a Python
2442Enhancement Proposal (PEP) before they can be accepted.
2443
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002444There are several important syntax enhancements, described in more
2445detail below:
2446
2447 - Augmented assignment, e.g. x += 1
2448
2449 - List comprehensions, e.g. [x**2 for x in range(10)]
2450
2451 - Extended import statement, e.g. import Module as Name
2452
2453 - Extended print statement, e.g. print >> file, "Hello"
2454
2455Other important changes:
2456
2457 - Optional collection of cyclical garbage
2458
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002459Python Enhancement Proposal (PEP)
2460---------------------------------
2461
2462PEP stands for Python Enhancement Proposal. A PEP is a design
2463document providing information to the Python community, or describing
2464a new feature for Python. The PEP should provide a concise technical
2465specification of the feature and a rationale for the feature.
2466
2467We intend PEPs to be the primary mechanisms for proposing new
2468features, for collecting community input on an issue, and for
2469documenting the design decisions that have gone into Python. The PEP
2470author is responsible for building consensus within the community and
2471documenting dissenting opinions.
2472
2473The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002474
2475Augmented Assignment
2476--------------------
2477
2478This must have been the most-requested feature of the past years!
2479Eleven new assignment operators were added:
2480
Guido van Rossume905e952000-09-05 12:42:46 +00002481 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002482
2483For example,
2484
2485 A += B
2486
2487is similar to
2488
2489 A = A + B
2490
2491except that A is evaluated only once (relevant when A is something
2492like dict[index].attr).
2493
2494However, if A is a mutable object, A may be modified in place. Thus,
2495if A is a number or a string, A += B has the same effect as A = A+B
2496(except A is only evaluated once); but if a is a list, A += B has the
2497same effect as A.extend(B)!
2498
2499Classes and built-in object types can override the new operators in
2500order to implement the in-place behavior; the not-in-place behavior is
2501used automatically as a fallback when an object doesn't implement the
2502in-place behavior. For classes, the method name is derived from the
2503method name for the corresponding not-in-place operator by inserting
2504an 'i' in front of the name, e.g. __iadd__ implements in-place
2505__add__.
2506
2507Augmented assignment was implemented by Thomas Wouters.
2508
2509
2510List Comprehensions
2511-------------------
2512
2513This is a flexible new notation for lists whose elements are computed
2514from another list (or lists). The simplest form is:
2515
2516 [<expression> for <variable> in <sequence>]
2517
Guido van Rossum56db0952000-09-06 23:34:25 +00002518For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002519This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002520
2521You can also add a condition:
2522
2523 [<expression> for <variable> in <sequence> if <condition>]
2524
2525For example, [w for w in words if w == w.lower()] would yield the list
2526of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002527than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002528
2529You can also have nested for loops and more than one 'if' clause. For
2530example, here's a function that flattens a sequence of sequences::
2531
2532 def flatten(seq):
2533 return [x for subseq in seq for x in subseq]
2534
2535 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2536
2537This prints
2538
2539 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2540
2541List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002542Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002543
2544
2545Extended Import Statement
2546-------------------------
2547
2548Many people have asked for a way to import a module under a different
2549name. This can be accomplished like this:
2550
2551 import foo
2552 bar = foo
2553 del foo
2554
2555but this common idiom gets old quickly. A simple extension of the
2556import statement now allows this to be written as follows:
2557
2558 import foo as bar
2559
2560There's also a variant for 'from ... import':
2561
2562 from foo import bar as spam
2563
2564This also works with packages; e.g. you can write this:
2565
2566 import test.regrtest as regrtest
2567
2568Note that 'as' is not a new keyword -- it is recognized only in this
2569context (this is only possible because the syntax for the import
2570statement doesn't involve expressions).
2571
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002572Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002573
2574
2575Extended Print Statement
2576------------------------
2577
2578Easily the most controversial new feature, this extension to the print
2579statement adds an option to make the output go to a different file
2580than the default sys.stdout.
2581
2582For example, to write an error message to sys.stderr, you can now
2583write:
2584
2585 print >> sys.stderr, "Error: bad dog!"
2586
2587As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002588evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002589
2590 print >> None, "Hello world"
2591
2592is equivalent to
2593
2594 print "Hello world"
2595
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002596Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002597
2598
2599Optional Collection of Cyclical Garbage
2600---------------------------------------
2601
2602Python is now equipped with a garbage collector that can hunt down
2603cyclical references between Python objects. It's no replacement for
2604reference counting; in fact, it depends on the reference counts being
2605correct, and decides that a set of objects belong to a cycle if all
2606their reference counts can be accounted for from their references to
2607each other. This devious scheme was first proposed by Eric Tiedemann,
2608and brought to implementation by Neil Schemenauer.
2609
2610There's a module "gc" that lets you control some parameters of the
2611garbage collection. There's also an option to the configure script
2612that lets you enable or disable the garbage collection. In 2.0b1,
2613it's on by default, so that we (hopefully) can collect decent user
2614experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002615performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002616off by default in the final 2.0 release.
2617
2618
2619Smaller Changes
2620---------------
2621
2622A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2623map(None, seq1, seq2, ...) when the sequences have the same length;
2624i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2625the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002626zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002627
2628sys.version_info is a tuple (major, minor, micro, level, serial).
2629
2630Dictionaries have an odd new method, setdefault(key, default).
2631dict.setdefault(key, default) returns dict[key] if it exists; if not,
2632it sets dict[key] to default and returns that value. Thus:
2633
2634 dict.setdefault(key, []).append(item)
2635
2636does the same work as this common idiom:
2637
2638 if not dict.has_key(key):
2639 dict[key] = []
2640 dict[key].append(item)
2641
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002642There are two new variants of SyntaxError that are raised for
2643indentation-related errors: IndentationError and TabError.
2644
2645Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2646escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002647
2648The limits on the size of expressions and file in Python source code
2649have been raised from 2**16 to 2**32. Previous versions of Python
2650were limited because the maximum argument size the Python VM accepted
2651was 2**16. This limited the size of object constructor expressions,
2652e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2653limit was raised thanks to a patch by Charles Waldman that effectively
2654fixes the problem. It is now much more likely that you will be
2655limited by available memory than by an arbitrary limit in Python.
2656
2657The interpreter's maximum recursion depth can be modified by Python
2658programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2659limit is the maximum number of recursive calls that can be made by
2660Python code. The limit exists to prevent infinite recursion from
2661overflowing the C stack and causing a core dump. The default value is
26621000. The maximum safe value for a particular platform can be found
2663by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002664
2665New Modules and Packages
2666------------------------
2667
2668atexit - for registering functions to be called when Python exits.
2669
2670imputil - Greg Stein's alternative API for writing custom import
2671hooks.
2672
2673pyexpat - an interface to the Expat XML parser, contributed by Paul
2674Prescod.
2675
2676xml - a new package with XML support code organized (so far) in three
2677subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2678would fill a volume. There's a special feature whereby a
2679user-installed package named _xmlplus overrides the standard
2680xmlpackage; this is intended to give the XML SIG a hook to distribute
2681backwards-compatible updates to the standard xml package.
2682
2683webbrowser - a platform-independent API to launch a web browser.
2684
2685
Guido van Rossume905e952000-09-05 12:42:46 +00002686Changed Modules
2687---------------
2688
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002689array -- new methods for array objects: count, extend, index, pop, and
2690remove
2691
2692binascii -- new functions b2a_hex and a2b_hex that convert between
2693binary data and its hex representation
2694
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002695calendar -- Many new functions that support features including control
2696over which day of the week is the first day, returning strings instead
2697of printing them. Also new symbolic constants for days of week,
2698e.g. MONDAY, ..., SUNDAY.
2699
2700cgi -- FieldStorage objects have a getvalue method that works like a
2701dictionary's get method and returns the value attribute of the object.
2702
2703ConfigParser -- The parser object has new methods has_option,
2704remove_section, remove_option, set, and write. They allow the module
2705to be used for writing config files as well as reading them.
2706
2707ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002708optionally support the RFC 959 REST command.
2709
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002710gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002711
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002712httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2713the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002714
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002715locale -- implement getdefaultlocale for Win32 and Macintosh
2716
2717marshal -- no longer dumps core when marshaling deeply nested or
2718recursive data structures
2719
2720os -- new functions isatty, seteuid, setegid, setreuid, setregid
2721
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002722os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2723support under Unix.
2724
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002725os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002726
2727os.path -- fix semantics of os.path.commonprefix
2728
2729smtplib -- support for sending very long messages
2730
2731socket -- new function getfqdn()
2732
2733readline -- new functions to read, write and truncate history files.
2734The readline section of the library reference manual contains an
2735example.
2736
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002737select -- add interface to poll system call
2738
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002739shutil -- new copyfileobj function
2740
2741SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2742HTTP server.
2743
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002744Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002745
2746urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002747e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002748
2749whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002750
2751
2752Obsolete Modules
2753----------------
2754
2755None. However note that 1.6 made a whole slew of modules obsolete:
2756stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2757poly, zmod, strop, util, whatsound.
2758
2759
2760Changed, New, Obsolete Tools
2761----------------------------
2762
Tim Peters8b092332000-09-05 20:15:25 +00002763None.
Guido van Rossume905e952000-09-05 12:42:46 +00002764
2765
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002766C-level Changes
2767---------------
2768
2769Several cleanup jobs were carried out throughout the source code.
2770
2771All C code was converted to ANSI C; we got rid of all uses of the
2772Py_PROTO() macro, which makes the header files a lot more readable.
2773
2774Most of the portability hacks were moved to a new header file,
2775pyport.h; several other new header files were added and some old
2776header files were removed, in an attempt to create a more rational set
2777of header files. (Few of these ever need to be included explicitly;
2778they are all included by Python.h.)
2779
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002780Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002781and Win64, especially for the new Intel Itanium processor. Mick also
2782added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002783
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002784The C APIs to return an object's size have been update to consistently
2785use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2786previous versions, the abstract interfaces used PyXXX_Length and the
2787concrete interfaces used PyXXX_Size. The old names,
2788e.g. PyObject_Length, are still available for backwards compatibility
2789at the API level, but are deprecated.
2790
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002791The PyOS_CheckStack function has been implemented on Windows by
2792Fredrik Lundh. It prevents Python from failing with a stack overflow
2793on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002794
2795The GC changes resulted in creation of two new slots on object,
2796tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002797the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002798
2799The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002800C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002801
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002802PyErr_Format has been updated to automatically calculate the size of
2803the buffer needed to hold the formatted result string. This change
2804prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002805
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002806New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002807
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002808PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2809that are the same as their non-Ex counterparts except they take an
2810extra flag argument that tells them to close the file when done.
2811
2812XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002813
Tim Peters8b092332000-09-05 20:15:25 +00002814
2815Windows Changes
2816---------------
2817
2818New popen2/popen3/peopen4 in os module (see Changed Modules above).
2819
2820os.popen is much more usable on Windows 95 and 98. See Microsoft
2821Knowledge Base article Q150956. The Win9x workaround described there
2822is implemented by the new w9xpopen.exe helper in the root of your
2823Python installation. Note that Python uses this internally; it is not
2824a standalone program.
2825
2826Administrator privileges are no longer required to install Python
2827on Windows NT or Windows 2000. If you have administrator privileges,
2828Python's registry info will be written under HKEY_LOCAL_MACHINE.
2829Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002830under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002831uses of Python, but will prevent some advanced uses from working
2832(for example, running a Python script as an NT service, or possibly
2833from CGI).
2834
2835[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2836installer; instead, it installs the needed Tcl/Tk files directly in the
2837Python directory. If you already have a Tcl/Tk installation, this
2838wastes some disk space (about 4 Megs) but avoids problems with
2839conflicting Tcl/Tk installations, and makes it much easier for Python
2840to ensure that Tcl/Tk can find all its files.
2841
2842[This was new in 1.6] The Windows installer now installs by default in
2843\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2844
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002845
2846Updates to the changes between 1.5.2 and 1.6
2847--------------------------------------------
2848
2849The 1.6 NEWS file can't be changed after the release is done, so here
2850is some late-breaking news:
2851
2852New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2853and changes to getlocale() and setlocale().
2854
2855The new module is now enabled per default.
2856
2857It is not true that the encodings codecs cannot be used for normal
2858strings: the string.encode() (which is also present on 8-bit strings
2859!) allows using them for 8-bit strings too, e.g. to convert files from
2860cp1252 (Windows) to latin-1 or vice-versa.
2861
2862Japanese codecs are available from Tamito KAJIYAMA:
2863http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2864
2865
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002866======================================================================