blob: 2a29558ee20acc472ecfefdaffe0b92777a7169c [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
Guido van Rossum12d955c2001-10-26 14:56:06 +00007- Assignment to object.__dict__ is now possible, for objects that are
8 instances of new-style classes that have a __dict__ (unless the base
9 class forbids it).
10
Tim Peters1fc240e2001-10-26 05:06:50 +000011- dictionary() now accepts an iterable object producing 2-sequences.
12 For example, dictionary(d.items()) == d for any dictionary d. The
13 argument, and the elements of the argument, can be any iterable
14 objects.
15
Guido van Rossumc8e56452001-10-22 00:43:43 +000016- Methods of built-in types now properly check for keyword arguments
17 (formerly these were silently ignored). The only built-in methods
18 that take keyword arguments are __call__, __init__ and __new__.
19
Guido van Rossum86443212001-10-27 22:28:54 +000020- The socket function has been converted to a type; see below.
21
Tim Peters84362bc2001-10-19 17:55:30 +000022Core and builtins
23
Guido van Rossum12d955c2001-10-26 14:56:06 +000024- Clarified the error messages for unsupported operands to an operator
25 (like 1 + '').
26
Tim Peters84362bc2001-10-19 17:55:30 +000027Extension modules
28
Guido van Rossum12d955c2001-10-26 14:56:06 +000029- The socket module defines a new method for socket objects,
30 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +000031 send() until all data has been sent. Also, the socket function has
32 been converted to a subclassable type, like list and tuple (etc.)
33 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +000034
35- Various bugfixes to the curses module. There is now a test suite
36 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000037
Tim Peters84362bc2001-10-19 17:55:30 +000038Library
39
Tim Peters98791af2001-10-23 01:59:54 +000040- Traceback objects are now scanned by cyclic garbage collection, so
41 cycles created by casual use of sys.exc_info() no longer cause
42 permanent memory leaks (provided garbage collection is enabled).
43
Guido van Rossum49192142001-10-24 20:51:44 +000044- os.extsep -- a new variable needed by the RISCOS support. It is the
45 separator used by extensions, and is '.' on all platforms except
46 RISCOS, where it is '/'. There is no need to use this variable
47 unless you have a masochistic desire to port your code to RISCOS.
48
Tim Peters84362bc2001-10-19 17:55:30 +000049Tools/Demos
50
51Build
52
53C API
54
Tim Peters1fc240e2001-10-26 05:06:50 +000055- New function PySequence_Fast_GET_SIZE() returns the size of a non-
56 NULL result from PySequence_Fast(), more quickly than calling
57 PySequence_Size().
58
Tim Peters84362bc2001-10-19 17:55:30 +000059New platforms
60
Guido van Rossum86443212001-10-27 22:28:54 +000061- We've finally confirmed that this release builds on HP-UX 11.00,
62 *with* threads, and passes the test suite.
63
Guido van Rossum49192142001-10-24 20:51:44 +000064- Updated RISCOS port by Dietmar Schwertberger.
65
Tim Peters84362bc2001-10-19 17:55:30 +000066Tests
67
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000068- Added a test script for the curses module. It isn't run automatically;
69 regrtest.py must be run with '-u curses' to enable it.
70
Tim Peters84362bc2001-10-19 17:55:30 +000071Windows
72
73
Tim Petersabf925f2001-09-28 21:53:42 +000074What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +000075Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +000076===========================
77
78Type/class unification and new-style classes
79
Guido van Rossum687ae002001-10-15 22:03:32 +000080- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +000081 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +000082 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000083 remains: the __dict__ of a new-style class is a read-only proxy; you
84 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000085 __defined__ attribute of new-style types no longer exists, for lack
86 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +000087 future a __cache__ may be resurrected with a similar function, if I
88 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +000089
Tim Peters1c9ca872001-10-04 06:43:12 +000090- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
91 always returned None, even when there was a class docstring).
92
93- doctest now finds and runs docstrings attached to new-style classes,
94 class methods, static methods, and properties.
95
Guido van Rossum9074ef62001-10-16 21:34:49 +000096Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +000097
Guido van Rossuma8bcf802001-10-15 15:53:58 +000098- A very subtle syntactical pitfall in list comprehensions was fixed.
99 For example: [a+b for a in 'abc', for b in 'def']. The comma in
100 this example is a mistake. Previously, this would silently let 'a'
101 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
102 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
103 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
104 Note that [a for a in <singleton>] is a convoluted way to say
105 [<singleton>] anyway, so it's not like any expressiveness is lost.
106
Guido van Rossum9074ef62001-10-16 21:34:49 +0000107- getattr(obj, name, default) now only catches AttributeError, as
108 documented, rather than returning the default value for all
109 exceptions (which could mask bugs in a __getattr__ hook, for
110 example).
111
Fred Drakecb7a6b52001-10-22 18:41:51 +0000112- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000113 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000114 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000115 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000116
Guido van Rossum1c486092001-10-19 02:05:35 +0000117- unicode(obj) now behaves more like str(obj), accepting arbitrary
118 objects, and calling a __unicode__ method if it exists.
119 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000120 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000121
Barry Warsawf6fb1712001-10-19 05:35:40 +0000122- isinstance() now allows any object as the first argument and a
123 class, a type or something with a __bases__ tuple attribute for the
124 second argument. The second argument may also be a tuple of a
125 class, type, or something with __bases__, in which case isinstance()
126 will return true if the first argument is an instance of any of the
127 things contained in the second argument tuple. E.g.
128
129 isinstance(x, (A, B))
130
131 returns true if x is an instance of A or B.
132
Guido van Rossum9074ef62001-10-16 21:34:49 +0000133Extension modules
134
135- thread.start_new_thread() now returns the thread ID (previously None).
136
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000137- binascii has now two quopri support functions, a2b_qp and b2a_qp.
138
Guido van Rossumc524d952001-10-19 01:31:59 +0000139- readline now supports setting the startup_hook and the
140 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000141
Guido van Rossumc524d952001-10-19 01:31:59 +0000142- os and posix supports chroot(), setgroups() and unsetenv() where
143 available. The stat(), fstat(), statvfs() and fstatvfs() functions
144 now return "pseudo-sequences" -- the various fields can now be
145 accessed as attributes (e.g. os.stat("/").st_mtime) but for
146 backwards compatibility they also behave as a fixed-length sequence.
147 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000148 attributes.
149
150- time: localtime(), gmtime() and strptime() now return a
151 pseudo-sequence similar to the os.stat() return value, with
152 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000153
Guido van Rossum9074ef62001-10-16 21:34:49 +0000154- Decompression objects in the zlib module now accept an optional
155 second parameter to decompress() that specifies the maximum amount
156 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000157
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000158- optional SSL support in the socket module now exports OpenSSL
159 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
160 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000161 automatically seed its PRNG. Also, the keyfile and certfile
162 arguments to socket.ssl() are now optional.
163
164- posixmodule (and by extension, the os module on POSIX platforms) now
165 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000166
Guido van Rossum9074ef62001-10-16 21:34:49 +0000167Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000168
Tim Peters7402f792001-10-02 03:53:41 +0000169- doctest now excludes functions and classes not defined by the module
170 being tested, thanks to Tim Hochberg.
171
Fred Drakecb7a6b52001-10-22 18:41:51 +0000172- HotShot, a new profiler implemented using a C-based callback, has
173 been added. This substantially reduces the overhead of profiling,
174 but it is still quite preliminary. Support modules and
175 documentation will be added in upcoming releases (before 2.2 final).
176
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000177- profile now produces correct output in situations where an exception
178 raised in Python is cleared by C code (e.g. hasattr()). This used
179 to cause wrong output, including spurious claims of recursive
180 functions and attribution of time spent to the wrong function.
181
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000182 The code and documentation for the derived OldProfile and HotProfile
183 profiling classes was removed. The code hasn't worked for years (if
184 you tried to use them, they raised exceptions). OldProfile
185 intended to reproduce the behavior of the profiler Python used more
186 than 7 years ago, and isn't interesting anymore. HotProfile intended
187 to provide a faster profiler (but producing less information), and
188 that's a worthy goal we intend to meet via a different approach (but
189 without losing information).
190
Tim Peterscce092d2001-10-09 05:31:56 +0000191- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000192 a much better system-specific calibration constant. The constant can
193 now be specified in an instance constructor, or as a Profile class or
194 instance variable, instead of by editing profile.py's source code.
195 Calibration must still be done manually (see the docs for the profile
196 module).
197
198 Note that Profile.calibrate() must be overriden by subclasses.
199 Improving the accuracy required exploiting detailed knowledge of
200 profiler internals; the earlier method abstracted away the details
201 and measured a simplified model instead, but consequently computed
202 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000203
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000204- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000205 which indicates whether output is intended for the header 'Q'
206 encoding.
207
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000208- The SocketServer.ThreadingMixIn class now closes the request after
209 finish_request() returns. (Not when it errors out though.)
210
Barry Warsawf6fb1712001-10-19 05:35:40 +0000211- The nntplib module's NNTP.body() method has grown a `file' argument
212 to allow saving the message body to a file.
213
214- The email package has added a class email.Parser.HeaderParser which
215 only parses headers and does not recurse into the message's body.
216 Also, the module/class MIMEAudio has been added for representing
217 audio data (contributed by Anthony Baxter).
218
219- ftplib should be able to handle files > 2GB.
220
221- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
222 ON, and OFF.
223
Fred Drakecb7a6b52001-10-22 18:41:51 +0000224- xml.dom.minidom NodeList objects now support the length attribute
225 and item() method as required by the DOM specifications.
226
Guido van Rossumed554f62001-10-02 23:15:37 +0000227Tools/Demos
228
229- Demo/dns was removed. It no longer serves any purpose; a package
230 derived from it is now maintained by Anthony Baxter, see
231 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000232
Barry Warsawf6fb1712001-10-19 05:35:40 +0000233- The freeze tool has been made more robust, and two new options have
234 been added: -X and -E.
235
Tim Petersabf925f2001-09-28 21:53:42 +0000236Build
237
Barry Warsawf6fb1712001-10-19 05:35:40 +0000238- configure will use CXX in LINKCC if CXX is used to build main() and
239 the system requires to link a C++ main using the C++ compiler.
240
Tim Petersabf925f2001-09-28 21:53:42 +0000241C API
242
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000243- The documentation for the tp_compare slot is updated to require that
244 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
245 not correct. This is not yet enforced but will be enforced in
246 Python 2.3; even later, we may use -2 to indicate errors and +2 for
247 "NotImplemented". Right now, -1 should be used for an error return.
248
Tim Petersd38b1c72001-09-30 05:09:37 +0000249- PyLong_AsLongLong() now accepts int (as well as long) arguments.
250 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
251 as long) arguments.
252
Guido van Rossum3c288632001-10-16 21:13:49 +0000253- PyThread_start_new_thread() now returns a long int giving the thread
254 ID, if one can be calculated; it returns -1 for error, 0 if no
255 thread ID is calculated (this is an incompatible change, but only
256 the thread module used this API). This code has only really been
257 tested on Linux and Windows; other platforms please beware (and
258 report any bugs or strange behavior).
259
Guido van Rossum1c486092001-10-19 02:05:35 +0000260- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
261 input.
262
Tim Petersabf925f2001-09-28 21:53:42 +0000263New platforms
264
265Tests
266
267Windows
268
Tim Peters04cf1d32001-10-09 22:39:40 +0000269- Installer: If you install IDLE, and don't disable file-extension
270 registration, a new "Edit with IDLE" context (right-click) menu entry
271 is created for .py and .pyw files.
272
Tim Peters1ce3cf72001-10-01 17:58:40 +0000273- The signal module now supports SIGBREAK on Windows, thanks to Steven
274 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
275 action remains to call Win32 ExitProcess(). This can be changed via
276 signal.signal(). For example:
277
278 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
279 # (SIGINT) behavior.
280 import signal
281 signal.signal(signal.SIGBREAK,
282 signal.default_int_handler)
283
284 try:
285 while 1:
286 pass
287 except KeyboardInterrupt:
288 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
289 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
290 # program without the possibility for any Python-level cleanup).
291 print "Clean exit"
292
Tim Petersabf925f2001-09-28 21:53:42 +0000293
Tim Petersb07352e2001-09-08 01:25:47 +0000294What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000295Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000296===========================
297
Guido van Rossum808eea72001-09-25 04:15:41 +0000298Type/class unification and new-style classes
299
300- pydoc and inspect are now aware of new-style classes;
301 e.g. help(list) at the interactive prompt now shows proper
302 documentation for all operations on list objects.
303
304- Applications using Jim Fulton's ExtensionClass module can now safely
305 be used with Python 2.2. In particular, Zope 2.4.1 now works with
306 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
307 examples also work again. It is hoped that Gtk and Boost also work
308 with 2.2a4 and beyond. (If you can confirm this, please write
309 webmaster@python.org; if there are still problems, please open a bug
310 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000311
Tim Peters66c1a522001-09-24 21:17:50 +0000312- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
313 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
314 in the constructed property object. fget, fset and fdel weren't
315 discoverable from Python in 2.2a3. __doc__ is new, and allows to
316 associate a docstring with a property.
317
Guido van Rossum808eea72001-09-25 04:15:41 +0000318- Comparison overloading is now more completely implemented. For
319 example, a str subclass instance can properly be compared to a str
320 instance, and it can properly overload comparison. Ditto for most
321 other built-in object types.
322
323- The repr() of new-style classes has changed; instead of <type
324 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
325 *except* for built-in types, which are still rendered as <type
326 'Foo'> (to avoid upsetting existing code that might parse or
327 otherwise rely on repr() of certain type objects).
328
329- The repr() of new-style objects is now always <Foo object at XXX>;
330 previously, it was sometimes <Foo instance at XXX>.
331
332- For new-style classes, what was previously called __getattr__ is now
333 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000334 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000335 one in classic classes is defined which is called only if regular
336 attribute access raises AttributeError; to catch *all* attribute
337 access, you can use __getattribute__ (for new-style classes). If
338 both are defined, __getattribute__ is called first, and if it raises
339 AttributeError, __getattr__ is called.
340
341- The __class__ attribute of new-style objects can be assigned to.
342 The new class must have the same C-level object layout as the old
343 class.
344
345- The builtin file type can be subclassed now. In the usual pattern,
346 "file" is the name of the builtin type, and file() is a new builtin
347 constructor, with the same signature as the builtin open() function.
348 file() is now the preferred way to open a file.
349
350- Previously, __new__ would only see sequential arguments passed to
351 the type in a constructor call; __init__ would see both sequential
352 and keyword arguments. This made no sense whatsoever any more, so
353 now both __new__ and __init__ see all arguments.
354
355- Previously, hash() applied to an instance of a subclass of str or
356 unicode always returned 0. This has been repaired.
357
358- Previously, an operation on an instance of a subclass of an
359 immutable type (int, long, float, complex, tuple, str, unicode),
360 where the subtype didn't override the operation (and so the
361 operation was handled by the builtin type), could return that
362 instance instead a value of the base type. For example, if s was of
363 a str sublass type, s[:] returned s as-is. Now it returns a str
364 with the same value as s.
365
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000366- Provisional support for pickling new-style objects has been added.
367
Guido van Rossum808eea72001-09-25 04:15:41 +0000368Core
369
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000370- file.writelines() now accepts any iterable object producing strings.
371
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000372- PyUnicode_FromEncodedObject() now works very much like
373 PyObject_Str(obj) in that it tries to use __str__/tp_str
374 on the object if the object is not a string or buffer. This
375 makes unicode() behave like str() when applied to non-string/buffer
376 objects.
377
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000378- PyFile_WriteObject now passes Unicode objects to the file's write
379 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000380 of a print statement must support Unicode objects, i.e. they must
381 at least convert them into ASCII strings.
382
Guido van Rossum624c8af2001-09-18 15:21:04 +0000383- Thread scheduling on Solaris should be improved; it is no longer
384 necessary to insert a small sleep at the start of a thread in order
385 to let other runnable threads be scheduled.
386
Tim Petersb07352e2001-09-08 01:25:47 +0000387Library
388
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000389- StringIO.StringIO instances and cStringIO.StringIO instances support
390 read character buffer compatible objects for their .write() methods.
391 These objects are converted to strings and then handled as such
392 by the instances.
393
Barry Warsaw2f600732001-09-24 04:28:10 +0000394- The "email" package has been added. This is basically a port of the
395 mimelib package <http://sf.net/projects/mimelib> with API changes
396 and some implementations updated to use iterators and generators.
397
Tim Peters8a9c2842001-09-22 21:30:22 +0000398- difflib.ndiff() and difflib.Differ.compare() are generators now. This
399 restores the ability of Tools/scripts/ndiff.py to start producing output
400 before the entire comparison is complete.
401
Barry Warsaw58b072d2001-09-22 04:44:21 +0000402- StringIO.StringIO instances and cStringIO.StringIO instances support
403 iteration just like file objects (i.e. their .readline() method is
404 called for each iteration until it returns an empty string).
405
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000406- The codecs module has grown four new helper APIs to access
407 builtin codecs: getencoder(), getdecoder(), getreader(),
408 getwriter().
409
Guido van Rossum624c8af2001-09-18 15:21:04 +0000410- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
411 simplifies writing XML RPC servers.
412
Barry Warsaw647d5e82001-09-28 17:01:02 +0000413- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000414 after interpretation of symbolic links. On non-Unix systems, this
415 is an alias for os.path.abspath().
416
Tim Peters16a77ad2001-09-08 04:00:12 +0000417- operator.indexOf() (PySequence_Index() in the C API) now works with any
418 iterable object.
419
Guido van Rossum624c8af2001-09-18 15:21:04 +0000420- smtplib now supports various authentication and security features of
421 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000422
Guido van Rossum624c8af2001-09-18 15:21:04 +0000423- hmac: a new module implementing keyed hashing for message
424 authentication.
425
426- mimetypes now recognizes more extensions and file types. At the
427 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000428
Guido van Rossum624c8af2001-09-18 15:21:04 +0000429- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000430 Python 2.2 bytecode generation. It has also been promoted from a
431 Tool to a standard library package. (Tools/compiler still exists as
432 a sample driver.)
433
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000434Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000435
Tim Petersb07352e2001-09-08 01:25:47 +0000436Build
437
Guido van Rossum624c8af2001-09-18 15:21:04 +0000438- Large file support (LFS) is now automatic when the platform supports
439 it; no more manual configuration tweaks are needed. On Linux, at
440 least, it's possible to have a system whose C library supports large
441 files but whose kernel doesn't; in this case, large file support is
442 still enabled but doesn't do you any good unless you upgrade your
443 kernel or share your Python executable with another system whose
444 kernel has large file support.
445
446- The configure script now supplies plausible defaults in a
447 cross-compilation environment. This doesn't mean that the supplied
448 values are always correct, or that cross-compilation now works
449 flawlessly -- but it's a first step (and it shuts up most of
450 autoconf's warnings about AC_TRY_RUN).
451
452- The Unix build is now a bit less chatty, courtesy of the parser
453 generator. The build is completely silent (except for errors) when
454 using "make -s", thanks to a -q option to setup.py.
455
Tim Petersb07352e2001-09-08 01:25:47 +0000456C API
457
Guido van Rossum624c8af2001-09-18 15:21:04 +0000458- The "structmember" API now supports some new flag bits to deny read
459 and/or write access to attributes in restricted execution mode.
460
Tim Petersb07352e2001-09-08 01:25:47 +0000461New platforms
462
Guido van Rossum624c8af2001-09-18 15:21:04 +0000463- Compaq's iPAQ handheld, running the "familiar" Linux distribution
464 (http://familiar.handhelds.org).
465
Tim Petersb07352e2001-09-08 01:25:47 +0000466Tests
467
Tim Peters8a9c2842001-09-22 21:30:22 +0000468- The "classic" standard tests, which work by comparing stdout to
469 an expected-output file under Lib/test/output/, no longer stop at
470 the first mismatch. Instead the test is run to completion, and a
471 variant of ndiff-style comparison is used to report all differences.
472 This is much easier to understand than the previous style of reporting.
473
474- The unittest-based standard tests now use regrtest's test_main()
475 convention, instead of running as a side-effect of merely being
476 imported. This allows these tests to be run in more natural and
477 flexible ways as unittests, outside the regrtest framework.
478
479- regrtest.py is much better integrated with unittest and doctest now,
480 especially in regard to reporting errors.
481
Tim Petersb07352e2001-09-08 01:25:47 +0000482Windows
483
Guido van Rossum624c8af2001-09-18 15:21:04 +0000484- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000485 that support it (NTFS under Windows 2000). See "What's New in
486 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000487
Tim Petersb07352e2001-09-08 01:25:47 +0000488
Tim Petersedc99312001-08-22 21:36:50 +0000489What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000490Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000491===========================
492
493Core
494
Tim Peters9fffa3e2001-09-04 05:14:19 +0000495- Conversion of long to float now raises OverflowError if the long is too
496 big to represent as a C double.
497
Tim Peters32f453e2001-09-03 08:35:41 +0000498- The 3-argument builtin pow() no longer allows a third non-None argument
499 if either of the first two arguments is a float, or if both are of
500 integer types and the second argument is negative (in which latter case
501 the arguments are converted to float, so this is really the same
502 restriction).
503
Tim Peters5d2b77c2001-09-03 05:47:38 +0000504- The builtin dir() now returns more information, and sometimes much
505 more, generally naming all attributes of an object, and all attributes
506 reachable from the object via its class, and from its class's base
507 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
508 an empty list. In 2.2a3,
509
510 >>> dir([])
511 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
512 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
513 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
514 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
515 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
516 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
517 'reverse', 'sort']
518
519 dir(module) continues to return only the module's attributes, though.
520
Tim Petersbdee63f2001-09-02 03:40:59 +0000521- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000522 than raising OverflowError. This is a partial implementation of PEP
523 237. You can use -Wdefault::OverflowWarning to enable a warning for
524 this situation, and -Werror::OverflowWarning to revert to the old
525 OverflowError exception.
526
Guido van Rossum61c345f2001-09-04 03:26:15 +0000527- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000528 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000529 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
530 -Qold, meaning the / operator has its classic meaning and no
531 warnings are issued. Using -Qwarn issues a run-time warning about
532 all uses of classic division for int and long arguments; -Qwarnall
533 also warns about classic division for float and complex arguments
534 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
535 new division by default, but only in the __main__ module. You can
536 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
537 __main__ module new division, and warns about classic division
538 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000539
Tim Petersbdee63f2001-09-02 03:40:59 +0000540- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000541 long, float, str, unicode, and tuple. (The types complex, list and
542 dictionary can also be subclassed; this was introduced earlier.)
543 Note that restrictions apply when subclassing immutable built-in
544 types: you can only affect the value of the instance by overloading
545 __new__. You can add mutable attributes, and the subclass instances
546 will have a __dict__ attribute, but you cannot change the "value"
547 (as implemented by the base class) of an immutable subclass instance
548 once it is created.
549
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000550- The dictionary constructor now takes an optional argument, a
551 mapping-like object, and initializes the dictionary from its
552 (key, value) pairs.
553
Tim Petersbdee63f2001-09-02 03:40:59 +0000554- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000555 "cooperative super calls" in a multiple inheritance setting. For an
556 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
557
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000558- A new built-in type, property, has been added. This enables the
559 creation of "properties". These are attributes implemented by
560 getter and setter functions (or only one of these for read-only or
561 write-only attributes), without the need to override __getattr__.
562 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000563
Tim Petersbdee63f2001-09-02 03:40:59 +0000564- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000565 liberalized, to allow leading zeroes. Examples of literals now
566 legal that were SyntaxErrors before:
567
568 00.0 0e3 0100j 07.5 00000000000000000008.
569
Tim Petersbdee63f2001-09-02 03:40:59 +0000570- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000571 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
572
Tim Petersedc99312001-08-22 21:36:50 +0000573Library
574
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000575- telnetlib includes symbolic names for the options, and support for
576 setting an option negotiation callback.
577
Tim Petersa40c7932001-09-05 22:36:56 +0000578- The new C standard no longer requires that math libraries set errno to
579 ERANGE on overflow. For platform libraries that exploit this new
580 freedom, Python's overflow-checking was wholly broken. A new overflow-
581 checking scheme attempts to repair that, but may not be reliable on all
582 platforms (C doesn't seem to provide anything both useful and portable
583 in this area anymore).
584
Martin v. Löwis44f86962001-09-05 13:44:54 +0000585- Asynchronous timeout actions are available through the new class
586 threading.Timer.
587
Tim Peters78526162001-09-05 00:53:45 +0000588- math.log and math.log10 now return sensible results for even huge
589 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
590
Tim Petersbdee63f2001-09-02 03:40:59 +0000591- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000592 currently held. See the docs for the imp module.
593
Tim Petersbdee63f2001-09-02 03:40:59 +0000594- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000595 dumps containing ints written on platforms where Python ints are 8 bytes.
596 When read on a box where Python ints are 4 bytes, such values are
597 converted to Python longs.
598
Tim Petersbdee63f2001-09-02 03:40:59 +0000599- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000600 code objects is no longer allowed. This plugs a security hole.
601
Steve Purcell6091cd62001-09-06 16:05:17 +0000602- unittest.TestResult instances no longer store references to tracebacks
603 generated by test failures. This prevents unexpected dangling references
604 to objects that should be garbage collected between tests.
605
Tim Petersedc99312001-08-22 21:36:50 +0000606Tools
607
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000608- Tools/scripts/fixdiv.py has been added which can be used to fix
609 division operators as per PEP 238.
610
Tim Petersedc99312001-08-22 21:36:50 +0000611Build
612
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000613- If you are an adventurous person using Mac OS X you may want to look at
614 Mac/OSX. There is a Makefile there that will build Python as a real Mac
615 application, which can be used for experimenting with Carbon or Cocoa.
616 Discussion of this on pythonmac-sig, please.
617
Tim Peters7eea37e2001-09-04 22:08:56 +0000618C API
619
620- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000621
Tim Peters9fffa3e2001-09-04 05:14:19 +0000622- Note that PyLong_AsDouble can fail! This has always been true, but no
623 callers checked for it. It's more likely to fail now, because overflow
624 errors are properly detected now. The proper way to check:
625
626 double x = PyLong_AsDouble(some_long_object);
627 if (x == -1.0 && PyErr_Occurred()) {
628 /* The conversion failed. */
629 }
630
Tim Petersbdee63f2001-09-02 03:40:59 +0000631- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000632 compile but will not participate in GC. To upgrade an extension
633 module:
634
635 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000636
Neil Schemenauer4042c692001-08-30 15:38:01 +0000637 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
638 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000639
Neil Schemenauer4042c692001-08-30 15:38:01 +0000640 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
641 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000642
Neil Schemenauer4042c692001-08-30 15:38:01 +0000643 - remove PyGC_HEAD_SIZE from object size calculations
644
645 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
646
Tim Petersbdee63f2001-09-02 03:40:59 +0000647- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000648 These can be used safely to construct string objects from a
649 sprintf-style format string (similar to the format string supported
650 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000651
Tim Petersedc99312001-08-22 21:36:50 +0000652New platforms
653
Tim Petersb7da0902001-09-02 23:01:43 +0000654- Stephen Hansen contributed patches sufficient to get a clean compile
655 under Borland C (Windows), but he reports problems running it and ran
656 out of time to complete the port. Volunteers? Expect a MemoryError
657 when importing the types module; this is probably shallow, and
658 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000659
Tim Petersedc99312001-08-22 21:36:50 +0000660Tests
661
662Windows
663
Tim Peters6e13a562001-09-06 00:32:15 +0000664- Large file support is now enabled on Win32 platforms as well as on
665 Win64. This means that, for example, you can use f.tell() and f.seek()
666 to manipulate files larger than 2 gigabytes (provided you have enough
667 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000668 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
669 filesize limit, and large file support makes no difference there.
670 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
671 NTFS has no practical limit on file size, and files of any size can be
672 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000673
Tim Petersbdee63f2001-09-02 03:40:59 +0000674- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000675 points to command.com (patch from Brian Quinlan).
676
Tim Petersedc99312001-08-22 21:36:50 +0000677
Tim Peters20f51a72001-07-21 02:31:40 +0000678What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000679Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000680===========================
681
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000682Build
683
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000684- Tim Peters developed a brand new Windows installer using Wise 8.1,
685 generously donated to us by Wise Solutions.
686
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000687- configure supports a new option --enable-unicode, with the values
688 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
689 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000690
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000691- A new configure option --enable-framework builds a Mac OS X framework,
692 which "make frameworkinstall" will install. This provides a starting
693 point for more mac-like functionality, join pythonmac-sig@python.org
694 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000695
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000696- The NeXT platform is no longer supported.
697
698- The `new' module is now statically linked.
699
Tim Peters0afb6092001-08-15 06:06:44 +0000700Tools
701
702- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000703 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000704 the module docstring for details.
705
Tim Peters20f51a72001-07-21 02:31:40 +0000706Tests
707
Tim Peters5e824c32001-08-12 22:25:01 +0000708- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000709 platforms, allowing to give clearer test result output. regrtest
710 also has optional --use/-u switch to run normally disabled tests
711 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000712
Tim Peters20f51a72001-07-21 02:31:40 +0000713- Several new tests in the standard test suite, with special thanks to
714 Nick Mathewson.
715
716Core
717
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000718- The floor division operator // has been added as outlined in PEP
719 238. The / operator still provides classic division (and will until
720 Python 3.0) unless "from __future__ import division" is included, in
721 which case the / operator will provide true division. The operator
722 module provides truediv() and floordiv() functions. Augmented
723 assignment variants are included, as are the equivalent overloadable
724 methods and C API methods. See the PEP for a full discussion:
725 <http://python.sf.net/peps/pep-0238.html>
726
Tim Peters6cd6a822001-08-17 22:11:27 +0000727- Future statements are now effective in simulated interactive shells
728 (like IDLE). This should "just work" by magic, but read Michael
729 Hudson's "Future statements in simulated shells" PEP 264 for full
730 details: <http://python.sf.net/peps/pep-0264.html>.
731
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000732- The type/class unification (PEP 252-253) was integrated into the
733 trunk and is not so tentative any more (the exact specification of
734 some features is still tentative). A lot of work has done on fixing
735 bugs and adding robustness and features (performance still has to
736 come a long way).
737
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000738- Warnings about a mismatch in the Python API during extension import
739 now use the Python warning framework (which makes it possible to
740 write filters for these warnings).
741
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000742- A function's __dict__ (aka func_dict) will now always be a
743 dictionary. It used to be possible to delete it or set it to None,
744 but now both actions raise TypeErrors. It is still legal to set it
745 to a dictionary object. Getting func.__dict__ before any attributes
746 have been assigned now returns an empty dictionary instead of None.
747
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000748- A new command line option, -E, was added which disables the use of
749 all environment variables, or at least those that are specifically
750 significant to Python. Usually those have a name starting with
751 "PYTHON". This was used to fix a problem where the tests fail if
752 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
753 older distribution.
754
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000755Library
756
Tim Peters5e824c32001-08-12 22:25:01 +0000757- New class Differ and new functions ndiff() and restore() in difflib.py.
758 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000759 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000760
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000761- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
762 value using the minimal quoting required for the value; more
763 reliable than using xml.sax.saxutils.escape() for attribute values.
764
765- Readline completion support for cmd.Cmd was added.
766
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000767- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
768
769- Added function threading.BoundedSemaphore()
770
771- Added Ka-Ping Yee's cgitb.py module.
772
773- The `new' module now exposes the CO_xxx flags.
774
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000775New platforms
776
777C API
778
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000779- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
780 which provide a cross-platform implementations for the
781 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
782 the standard sprintf() and vsprintf() C lib APIs, these versions
783 apply bounds checking on the used buffer which enhances protection
784 against buffer overruns.
785
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000786- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000787 and extensions using different Unicode widths is rendered next to
788 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000789 will result in an ImportError. Unicode extensions writers must make
790 sure to check the Unicode width compatibility in their extensions by
791 using at least one of the mangled Unicode APIs in the extension.
792
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000793- Two new flags METH_NOARGS and METH_O are available in method definition
794 tables to simplify implementation of methods with no arguments and a
795 single untyped argument. Calling such methods is more efficient than
796 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
797 deprecated.
798
Tim Petersc1731372001-08-04 08:12:36 +0000799Windows
800
801- "import module" now compiles module.pyw if it exists and nothing else
802 relevant is found.
803
Tim Peters20f51a72001-07-21 02:31:40 +0000804
Guido van Rossum55a78992001-07-17 17:22:32 +0000805What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +0000806Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +0000807===========================
808
809Core
Tim Petersa814db52001-05-14 07:05:58 +0000810
Tim Peters6d6c1a32001-08-02 04:15:00 +0000811- TENTATIVELY, a large amount of code implementing much of what's
812 described in PEP 252 (Making Types Look More Like Classes) and PEP
813 253 (Subtyping Built-in Types) was added. This will be released
814 with Python 2.2a1. Documentation will be provided separately
815 through http://www.python.org/2.2/. The purpose of releasing this
816 with Python 2.2a1 is to test backwards compatibility. It is
817 possible, though not likely, that a decision is made not to release
818 this code as part of 2.2 final, if any serious backwards
819 incompapatibilities are found during alpha testing that cannot be
820 repaired.
821
Guido van Rossum55a78992001-07-17 17:22:32 +0000822- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000823 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000824 more 'yield' statements. See PEP 255. Since this adds a new
825 keyword to the language, this feature must be enabled by including a
826 future statement: "from __future__ import generators" (see PEP 236).
827 Generators will become a standard feature in a future release
828 (probably 2.3). Without this future statement, 'yield' remains an
829 ordinary identifier, but a warning is issued each time it is used.
830 (These warnings currently don't conform to the warnings framework of
831 PEP 230; we intend to fix this in 2.2a2.)
832
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000833- The UTF-16 codec was modified to be more RFC compliant. It will now
834 only remove BOM characters at the start of the string and then
835 only if running in native mode (UTF-16-LE and -BE won't remove a
836 leading BMO character).
837
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000838- Strings now have a new method .decode() to complement the already
839 existing .encode() method. These two methods provide direct access
840 to the corresponding decoders and encoders of the registered codecs.
841
842 To enhance the usability of the .encode() method, the special
843 casing of Unicode object return values was dropped (Unicode objects
844 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000845
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000846 Both methods will now return whatever the codec in charge of the
847 requested encoding returns as object, e.g. Unicode codecs will
848 return Unicode objects when decoding is requested ("Ă¤Ă¶Ă¼".decode("latin-1")
849 will return u"Ă¤Ă¶Ă¼"). This enables codec writer to create codecs
850 for various simple to use conversions.
851
852 New codecs were added to demonstrate these new features (the .encode()
853 and .decode() columns indicate the type of the returned objects):
854
855 Name | .encode() | .decode() | Description
856 ----------------------------------------------------------------------
857 uu | string | string | UU codec (e.g. for email)
858 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000859 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000860 zlib | string | string | zlib compression
861 hex | string | string | 2-byte hex codec
862 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
863
Mark Hammond2a0af792001-05-14 03:09:36 +0000864- Some operating systems now support the concept of a default Unicode
865 encoding for file system operations. Notably, Windows supports 'mbcs'
866 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000867 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000868 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000869
870 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000871 functions that return filenames (such as os.listdir()) to return Python
872 string objects pre-encoded using the default file system encoding for
873 the platform. As this encoding is likely to be different from Python's
874 default encoding, converting this name to a Unicode object before passing
875 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000876 would attempt to use its default encoding (generally ASCII) rather than
877 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000878
Tim Petersa814db52001-05-14 07:05:58 +0000879 In general, this change simply removes surprises when working with
880 Unicode and the file system, making these operations work as you expect,
881 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000882 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000883
Tim Peters61dff2b2001-05-08 15:43:37 +0000884- Float (and complex) literals in source code were evaluated to full
885 precision only when running from a .py file; the same code loaded from a
886 .pyc (or .pyo) file could suffer numeric differences starting at about the
887 12th significant decimal digit. For example, on a machine with IEEE-754
888 floating arithmetic,
889
890 x = 9007199254740992.0
891 print long(x)
892
893 printed 9007199254740992 if run directly from .py, but 9007199254740000
894 if from a compiled (.pyc or .pyo) file. This was due to marshal using
895 str(float) instead of repr(float) when building code objects. marshal
896 now uses repr(float) instead, which should reproduce floats to full
897 machine precision (assuming the platform C float<->string I/O conversion
898 functions are of good quality).
899
900 This may cause floating-point results to change in some cases, and
901 usually for the better, but may also cause numerically unstable
902 algorithms to break.
903
Tim Peters2f228e72001-05-13 00:19:31 +0000904- The implementation of dicts suffers fewer collisions, which has speed
905 benefits. However, the order in which dict entries appear in dict.keys(),
906 dict.values() and dict.items() may differ from previous releases for a
907 given dict. Nothing is defined about this order, so no program should
908 rely on it. Nevertheless, it's easy to write test cases that rely on the
909 order by accident, typically because of printing the str() or repr() of a
910 dict to an "expected results" file. See Lib/test/test_support.py's new
911 sortdict(dict) function for a simple way to display a dict in sorted
912 order.
913
Tim Peters7a3bfc32001-06-12 01:22:22 +0000914- Many other small changes to dicts were made, resulting in faster
915 operation along the most common code paths.
916
Guido van Rossum10315822001-05-01 20:54:30 +0000917- Dictionary objects now support the "in" operator: "x in dict" means
918 the same as dict.has_key(x).
919
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000920- The update() method of dictionaries now accepts generic mapping
921 objects. Specifically the argument object must support the .keys()
922 and __getitem__() methods. This allows you to say, for example,
923 {}.update(UserDict())
924
Guido van Rossum10315822001-05-01 20:54:30 +0000925- Iterators were added; this is a generalized way of providing values
926 to a for loop. See PEP 234. There's a new built-in function iter()
927 to return an iterator. There's a new protocol to get the next value
928 from an iterator using the next() method (in Python) or the
929 tp_iternext slot (in C). There's a new protocol to get iterators
930 using the __iter__() method (in Python) or the tp_iter slot (in C).
931 Iterating (i.e. a for loop) over a dictionary generates its keys.
932 Iterating over a file generates its lines.
933
Tim Petersf553f892001-05-01 20:45:31 +0000934- The following functions were generalized to work nicely with iterator
935 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000936 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000937 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
938 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000939 join() method of strings
940 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000941 'x in y' and 'x not in y' (PySequence_Contains() in C API)
942 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000943 right-hand side of assignment statements with multiple targets, such as
944 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000945
Tim Petersd85e1022001-05-11 21:51:48 +0000946- Accessing module attributes is significantly faster (for example,
947 random.random or os.path or yourPythonModule.yourAttribute).
948
Tim Peterse63415e2001-05-08 04:38:29 +0000949- Comparing dictionary objects via == and != is faster, and now works even
950 if the keys and values don't support comparisons other than ==.
951
Tim Peters95bf9392001-05-10 08:32:44 +0000952- Comparing dictionaries in ways other than == and != is slower: there were
953 insecurities in the dict comparison implementation that could cause Python
954 to crash if the element comparison routines for the dict keys and/or
955 values mutated the dicts. Making the code bulletproof slowed it down.
956
Tim Peterseb28ef22001-06-02 05:27:19 +0000957- Collisions in dicts are resolved via a new approach, which can help
958 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000959 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000960 faster now. Thanks to Christian Tismer for pointing out the cause and
961 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000962
Tim Peters52e155e2001-06-16 05:42:57 +0000963- repr() is much faster for large containers (dict, list, tuple).
964
965
Tim Petersa814db52001-05-14 07:05:58 +0000966Library
967
Fred Drake960fdf92001-07-20 18:38:26 +0000968- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
969 were added to the string module. These a locale-indenpendent
970 constants, unlike letters, lowercase, and uppercase. These are now
971 use in appropriate locations in the standard library.
972
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000973- The flags used in dlopen calls can now be configured using
974 sys.setdlopenflags and queried using sys.getdlopenflags.
975
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000976- Fredrik Lundh's xmlrpclib is now a standard library module. This
977 provides full client-side XML-RPC support. In addition,
978 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
979 one asyncore-based). Thanks to Eric Raymond for the documentation.
980
Guido van Rossum643d3912001-07-05 14:46:25 +0000981- The xrange() object is simplified: it no longer supports slicing,
982 repetition, comparisons, efficient 'in' checking, the tolist()
983 method, or the start, stop and step attributes. See PEP 260.
984
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000985- A new function fnmatch.filter to filter lists of file names was added.
986
Barry Warsawffd674d2001-05-22 16:00:10 +0000987- calendar.py uses month and day names based on the current locale.
988
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000989- strop is now *really* obsolete (this was announced before with 1.6),
990 and issues DeprecationWarning when used (except for the four items
991 that are still imported into string.py).
992
Tim Petersa814db52001-05-14 07:05:58 +0000993- Cookie.py now sorts key+value pairs by key in output strings.
994
995- pprint.isrecursive(object) didn't correctly identify recursive objects.
996 Now it does.
997
Tim Peters95b3f782001-05-14 18:39:41 +0000998- pprint functions now much faster for large containers (tuple, list, dict).
999
Tim Peters7b9542a2001-06-10 23:40:19 +00001000- New 'q' and 'Q' format codes in the struct module, corresponding to C
1001 types "long long" and "unsigned long long" (on Windows, __int64). In
1002 native mode, these can be used only when the platform C compiler supports
1003 these types (when HAVE_LONG_LONG is #define'd by the Python config
1004 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001005 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1006 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001007
Guido van Rossum83213cc2001-06-12 16:48:52 +00001008- The site module installs a new built-in function 'help' that invokes
1009 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1010 it displays a message reminding the user to use 'help()' or
1011 'help(object)'.
1012
Tim Petersa814db52001-05-14 07:05:58 +00001013Tests
1014
1015- New test_mutants.py runs dict comparisons where the key and value
1016 comparison operators mutute the dicts randomly during comparison. This
1017 rapidly causes Python to crash under earlier releases (not for the faint
1018 of heart: it can also cause Win9x to freeze or reboot!).
1019
1020- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001021 pprint.isreadable() return sensible results. Also verifies that simple
1022 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001023
Tim Peters4324aa32001-05-28 22:30:08 +00001024C API
1025
1026- Removed the unused last_is_sticky argument from the internal
1027 _PyTuple_Resize(). If this affects you, you were cheating.
1028
1029
Guido van Rossum55a78992001-07-17 17:22:32 +00001030======================================================================
1031
1032
Guido van Rossumffe13be2001-04-16 18:46:45 +00001033What's New in Python 2.1 (final)?
1034=================================
1035
1036We only changed a few things since the last release candidate, all in
1037Python library code:
1038
1039- A bug in the locale module was fixed that affected locales which
1040 define no grouping for numeric formatting.
1041
1042- A few bugs in the weakref module's implementations of weak
1043 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1044 and the test suite was updated to check for these bugs.
1045
1046- An old bug in the os.path.walk() function (introduced in Python
1047 2.0!) was fixed: a non-existent file would cause an exception
1048 instead of being ignored.
1049
1050- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1051 PyChecker.
1052
1053
Guido van Rossum5b08f132001-04-16 02:05:23 +00001054What's New in Python 2.1c2?
1055===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001056
Guido van Rossum5b08f132001-04-16 02:05:23 +00001057A flurry of small changes, and one showstopper fixed in the nick of
1058time made it necessary to release another release candidate. The list
1059here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001060
Guido van Rossum5b08f132001-04-16 02:05:23 +00001061Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001062
Guido van Rossum5b08f132001-04-16 02:05:23 +00001063- Tim discovered a nasty bug in the dictionary code, caused by
1064 PyDict_Next() calling dict_resize(), and the GC code's use of
1065 PyDict_Next() violating an assumption in dict_items(). This was
1066 fixed with considerable amounts of band-aid, but the net effect is a
1067 saner and more robust implementation.
1068
1069- Made a bunch of symbols static that were accidentally global.
1070
1071Build and Ports
1072
1073- The setup.py script didn't check for a new enough version of zlib
1074 (1.1.3 is needed). Now it does.
1075
1076- Changed "make clean" target to also remove shared libraries.
1077
1078- Added a more general warning about the SGI Irix optimizer to README.
1079
1080Library
1081
1082- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1083 omitted the slash between host and file.html.
1084
1085- The mailbox module's _Mailbox class contained a completely broken
1086 and undocumented seek() method. Ripped it out.
1087
1088- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1089 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1090
1091- Fixed a few last-minute bugs in unittest.
1092
1093Extensions
1094
1095- Reverted the patch to the OpenSSL code in socketmodule.c to support
1096 RAND_status() and the EGD, and the subsequent patch that tried to
1097 fix it for pre-0.9.5 versions; the problem with the patch is that on
1098 some systems it issues a warning whenever socket is imported, and
1099 that's unacceptable.
1100
1101Tests
1102
1103- Fixed the pickle tests to work with "import test.test_pickle".
1104
1105- Tweaked test_locale.py to actually run the test Windows.
1106
1107- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1108 not "wb" (which is not a valid mode at all).
1109
1110- Fix pstats browser crashes. Import readline if it exists to make
1111 the user interface nicer.
1112
1113- Add "import thread" to the top of test modules that import the
1114 threading module (test_asynchat and test_threadedtempfile). This
1115 prevents test failures caused by a broken threading module resulting
1116 from a previously caught failed import.
1117
1118- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1119 needed on some platforms (e.g. Solaris 8) when the tests are run
1120 twice in succession.
1121
1122- Skip rather than fail test_sunaudiodev if no audio device is found.
1123
1124
1125What's New in Python 2.1c1?
1126===========================
1127
1128This list was significantly updated when 2.1c2 was released; the 2.1c1
1129release didn't mention most changes that were actually part of 2.1c1:
1130
1131Legal
1132
1133- Copyright was assigned to the Python Software Foundation (PSF) and a
1134 PSF license (very similar to the CNRI license) was added.
1135
1136- The CNRI copyright notice was updated to include 2001.
1137
1138Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001139
Guido van Rossumc9932722001-04-12 02:31:27 +00001140- After a public outcry, assignment to __debug__ is no longer illegal;
1141 instead, a warning is issued. It will become illegal in 2.2.
1142
Guido van Rossum5b08f132001-04-16 02:05:23 +00001143- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1144 "%#x" now always prepends "0x", even if the value is zero.
1145
1146- Fixed some nits in the bytecode compiler.
1147
1148- Fixed core dumps when calling certain kinds of non-functions.
1149
1150- Fixed various core dumps caused by reference count bugs.
1151
1152Build and Ports
1153
1154- Use INSTALL_SCRIPT to install script files.
1155
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001156- New port: SCO Unixware 7, by Billy G. Allie.
1157
Guido van Rossum5b08f132001-04-16 02:05:23 +00001158- Updated RISCOS port.
1159
1160- Updated BeOS port and notes.
1161
1162- Various other porting problems resolved.
1163
1164Library
1165
1166- The TERMIOS and SOCKET modules are now truly obsolete and
1167 unnecessary. Their symbols are incorporated in the termios and
1168 socket modules.
1169
1170- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1171 better tests for pickling.
1172
1173- threading: make Condition.wait() robust against KeyboardInterrupt.
1174
1175- zipfile: add support to zipfile to support opening an archive
1176 represented by an open file rather than a file name. Fix bug where
1177 the archive was not properly closed. Fixed a bug in this bugfix
1178 where flush() was called for a read-only file.
1179
1180- imputil: added an uninstall() method to the ImportManager.
1181
1182- Canvas: fixed bugs in lower() and tkraise() methods.
1183
1184- SocketServer: API change (added overridable close_request() method)
1185 so that the TCP server can explicitly close the request.
1186
1187- pstats: Eric Raymond added a simple interactive statistics browser,
1188 invoked when the module is run as a script.
1189
1190- locale: fixed a problem in format().
1191
1192- webbrowser: made it work when the BROWSER environment variable has a
1193 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1194 KDE 2. Fixed some other nits.
1195
1196- unittest: changes to allow using a different exception than
1197 AssertionError, and added a few more function aliases. Some other
1198 small changes.
1199
1200- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1201
1202- asynchat: fixed a critical bug in asynchat that slipped through the
1203 2.1b2 release. Fixed another rare bug.
1204
1205- Fix some unqualified except: clauses (always a bad code example).
1206
1207XML
1208
1209- pyexpat: new API get_version_string().
1210
1211- Fixed some minidom bugs.
1212
1213Extensions
1214
1215- Fixed a core dump in _weakref. Removed the weakref.mapping()
1216 function (it adds nothing to the API).
1217
1218- Rationalized the use of header files in the readline module, to make
1219 it compile (albeit with some warnings) with the very recent readline
1220 4.2, without breaking for earlier versions.
1221
1222- Hopefully fixed a buffering problem in linuxaudiodev.
1223
1224- Attempted a fix to make the OpenSSL support in the socket module
1225 work again with pre-0.9.5 versions of OpenSSL.
1226
1227Tests
1228
1229- Added a test case for asynchat and asyncore.
1230
1231- Removed coupling between tests where one test failing could break
1232 another.
1233
1234Tools
1235
1236- Ping added an interactive help browser to pydoc, fixed some nits
1237 in the rest of the pydoc code, and added some features to his
1238 inspect module.
1239
1240- An updated python-mode.el version 4.1 which integrates Ken
1241 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1242 much nicer in XEmacs and Emacs. When stepping through your program
1243 with pdb, in either the shell window or the *Python* window, the
1244 source file and line will be tracked by an arrow. Very cool!
1245
1246- IDLE: syntax warnings in interactive mode are changed into errors.
1247
1248- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001249 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001250
1251- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001252
Barry Warsaw11e89c72001-04-11 20:37:57 +00001253
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001254What's New in Python 2.1 beta 2?
1255================================
1256
Guido van Rossum053ae352001-03-22 14:17:21 +00001257(Unlisted are many fixed bugs, more documentation, etc.)
1258
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001259Core language, builtins, and interpreter
1260
Guido van Rossum053ae352001-03-22 14:17:21 +00001261- The nested scopes work (enabled by "from __future__ import
1262 nested_scopes") is completed; in particular, the future now extends
1263 into code executed through exec, eval() and execfile(), and into the
1264 interactive interpreter.
1265
1266- When calling a base class method (e.g. BaseClass.__init__(self)),
1267 this is now allowed even if self is not strictly spoken a class
1268 instance (e.g. when using metaclasses or the Don Beaudry hook).
1269
1270- Slice objects are now comparable but not hashable; this prevents
1271 dict[:] from being accepted but meaningless.
1272
1273- Complex division is now calculated using less braindead algorithms.
1274 This doesn't change semantics except it's more likely to give useful
1275 results in extreme cases. Complex repr() now uses full precision
1276 like float repr().
1277
1278- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1279
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001280- It is illegal to assign to the name __debug__, which is set when the
1281 interpreter starts. It is effectively a compile-time constant.
1282
1283- A warning will be issued if a global statement for a variable
1284 follows a use or assignment of that variable.
1285
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001286Standard library
1287
Guido van Rossum053ae352001-03-22 14:17:21 +00001288- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1289 inspired by JUnit), is now part of the standard library. You now
1290 have a choice of two testing frameworks: unittest requires you to
1291 write testcases as separate code, doctest gathers them from
1292 docstrings. Both approaches have their advantages and
1293 disadvantages.
1294
1295- A new module Tix was added, which wraps the Tix extension library
1296 for Tk. With that module, it is not necessary to statically link
1297 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1298 require" command. See Demo/tix/.
1299
1300- tzparse.py is now obsolete.
1301
1302- In gzip.py, the seek() and tell() methods are removed -- they were
1303 non-functional anyway, and it's better if callers can test for their
1304 existence with hasattr().
1305
1306Python/C API
1307
1308- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1309 that's already in the dictionary during a PyDict_Next() iteration.
1310 This used to fail occasionally when a dictionary resize operation
1311 could be triggered that would rehash all the keys. All other
1312 modifications to the dictionary are still off-limits during a
1313 PyDict_Next() iteration!
1314
1315- New extended APIs related to passing compiler variables around.
1316
1317- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1318 implement isinstance() and issubclass().
1319
1320- Py_BuildValue() now has a "D" conversion to create a Python complex
1321 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001322
Fred Drake4e262a92001-03-22 18:26:47 +00001323- Extensions types which support weak references must now set the
1324 field allocated for the weak reference machinery to NULL themselves;
1325 this is done to avoid the cost of checking each object for having a
1326 weakly referencable type in PyObject_INIT(), since most types are
1327 not weakly referencable.
1328
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001329- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1330 free variables and cell variables to and from the frame's f_locals.
1331
1332- Variants of several functions defined in pythonrun.h have been added
1333 to support the nested_scopes future statement. The variants all end
1334 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1335 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1336 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001337 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001338
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001339Distutils
1340
1341- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1342 into the release tree.
1343
Tim Peters0e57abf2001-05-02 07:39:38 +00001344- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001345 (an uninstaller, more customization of the installer's display)
1346
1347- from Jack Jansen: added Mac-specific code to generate a dialog for
1348 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001349 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001350 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001351
1352- added 'platforms' and 'keywords' to the set of metadata that can be
1353 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001354
1355- applied patches from Jason Tishler to make the compiler class work with
1356 Cygwin.
1357
1358
Tim Peters2fe289a2001-03-01 22:19:38 +00001359What's New in Python 2.1 beta 1?
1360================================
Tim Petersd66595f2001-02-04 03:09:53 +00001361
1362Core language, builtins, and interpreter
1363
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001364- Following an outcry from the community about the amount of code
1365 broken by the nested scopes feature introduced in 2.1a2, we decided
1366 to make this feature optional, and to wait until Python 2.2 (or at
1367 least 6 months) to make it standard. The option can be enabled on a
1368 per-module basis by adding "from __future__ import nested_scopes" at
1369 the beginning of a module (before any other statements, but after
1370 comments and an optional docstring). See PEP 236 (Back to the
1371 __future__) for a description of the __future__ statement. PEP 227
1372 (Statically Nested Scopes) has been updated to reflect this change,
1373 and to clarify the semantics in a number of endcases.
1374
1375- The nested scopes code, when enabled, has been hardened, and most
1376 bugs and memory leaks in it have been fixed.
1377
1378- Compile-time warnings are now generated for a number of conditions
1379 that will break or change in meaning when nested scopes are enabled:
1380
1381 - Using "from...import *" or "exec" without in-clause in a function
1382 scope that also defines a lambda or nested function with one or
1383 more free (non-local) variables. The presence of the import* or
1384 bare exec makes it impossible for the compiler to determine the
1385 exact set of local variables in the outer scope, which makes it
1386 impossible to determine the bindings for free variables in the
1387 inner scope. To avoid the warning about import *, change it into
1388 an import of explicitly name object, or move the import* statement
1389 to the global scope; to avoid the warning about bare exec, use
1390 exec...in... (a good idea anyway -- there's a possibility that
1391 bare exec will be deprecated in the future).
1392
1393 - Use of a global variable in a nested scope with the same name as a
1394 local variable in a surrounding scope. This will change in
1395 meaning with nested scopes: the name in the inner scope will
1396 reference the variable in the outer scope rather than the global
1397 of the same name. To avoid the warning, either rename the outer
1398 variable, or use a global statement in the inner function.
1399
Neil Schemenauera35c6882001-02-27 04:45:05 +00001400- An optional object allocator has been included. This allocator is
1401 optimized for Python objects and should be faster and use less memory
1402 than the standard system allocator. It is not enabled by default
1403 because of possible thread safety problems. The allocator is only
1404 protected by the Python interpreter lock and it is possible that some
1405 extension modules require a thread safe allocator. The object
1406 allocator can be enabled by providing the "--with-pymalloc" option to
1407 configure.
1408
Tim Petersd66595f2001-02-04 03:09:53 +00001409Standard library
1410
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001411- pyexpat now detects the expat version if expat.h defines it. A
1412 number of additional handlers are provided, which are only available
1413 since expat 1.95. In addition, the methods SetParamEntityParsing and
1414 GetInputContext of Parser objects are available with 1.95.x
1415 only. Parser objects now provide the ordered_attributes and
1416 specified_attributes attributes. A new module expat.model was added,
1417 which offers a number of additional constants if 1.95.x is used.
1418
1419- xml.dom offers the new functions registerDOMImplementation and
1420 getDOMImplementation.
1421
1422- xml.dom.minidom offers a toprettyxml method. A number of DOM
1423 conformance issues have been resolved. In particular, Element now
1424 has an hasAttributes method, and the handling of namespaces was
1425 improved.
1426
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001427- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1428 getting information about live Python code, and pydoc.py, a module
1429 for interactively converting docstrings to HTML or text.
1430 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001431 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001432 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1433 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001434
Tim Peters1eff7962001-03-01 02:31:33 +00001435- New library module difflib.py, primarily packaging the SequenceMatcher
1436 class at the heart of the popular ndiff.py file-comparison tool.
1437
1438- doctest.py (a framework for verifying Python code examples in docstrings)
1439 is now part of the std library.
1440
Tim Petersd66595f2001-02-04 03:09:53 +00001441Windows changes
1442
Guido van Rossume3955a82001-03-02 14:05:59 +00001443- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1444 small GUI that lets you browse the module docstrings using your
1445 default web browser.
1446
Tim Peters1eff7962001-03-01 02:31:33 +00001447- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1448 Platforms) is implemented. See
1449
1450 http://python.sourceforge.net/peps/pep-0235.html
1451
1452 for full details, especially the "Current Lower-Left Semantics" section.
1453 The new Windows import rules are simpler than before:
1454
1455 A. If the PYTHONCASEOK environment variable exists, same as
1456 before: silently accept the first case-insensitive match of any
1457 kind; raise ImportError if none found.
1458
1459 B. Else search sys.path for the first case-sensitive match; raise
1460 ImportError if none found.
1461
1462 The same rules have been implented on other platforms with case-
1463 insensitive but case-preserving filesystems too (including Cygwin, and
1464 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001465
Tim Peters25a9ce32001-02-19 07:06:36 +00001466- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1467 what it's supposed to do (and does do under NT and 2000) via direct
1468 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001469 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001470 all Win9x systems before.
1471
Tim Peters1eff7962001-03-01 02:31:33 +00001472- Build: Subproject _test (effectively) renamed to _testcapi.
1473
Tim Peters2fe289a2001-03-01 22:19:38 +00001474New platforms
1475
1476- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1477 Thanks to Steven Majewski!
1478
1479- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1480 Tishler!
1481
Guido van Rossum9089b272001-03-02 06:49:50 +00001482- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1483 Schwertberger! See RISCOS/README for more information -- it seems
1484 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001485 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001486
Tim Peters25a9ce32001-02-19 07:06:36 +00001487
Tim Petersd7b5e882001-01-25 03:36:26 +00001488What's New in Python 2.1 alpha 2?
1489=================================
Tim Peters40ead762001-01-27 05:35:26 +00001490
Tim Petersd7b5e882001-01-25 03:36:26 +00001491Core language, builtins, and interpreter
1492
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001493- Scopes nest. If a name is used in a function or class, but is not
1494 local, the definition in the nearest enclosing function scope will
1495 be used. One consequence of this change is that lambda statements
1496 could reference variables in the namespaces where the lambda is
1497 defined. In some unusual cases, this change will break code.
1498
1499 In all previous version of Python, names were resolved in exactly
1500 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001501 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001502 function A is defined within a function B, the names bound in B are
1503 not visible in A. The new rules make names bound in B visible in A,
1504 unless A contains a name binding that hides the binding in B.
1505
1506 Section 4.1 of the reference manual describes the new scoping rules
1507 in detail. The test script in Lib/test/test_scope.py demonstrates
1508 some of the effects of the change.
1509
1510 The new rules will cause existing code to break if it defines nested
1511 functions where an outer function has local variables with the same
1512 name as globals or builtins used by the inner function. Example:
1513
1514 def munge(str):
1515 def helper(x):
1516 return str(x)
1517 if type(str) != type(''):
1518 str = helper(str)
1519 return str.strip()
1520
1521 Under the old rules, the name str in helper() is bound to the
1522 builtin function str(). Under the new rules, it will be bound to
1523 the argument named str and an error will occur when helper() is
1524 called.
1525
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001526- The compiler will report a SyntaxError if "from ... import *" occurs
1527 in a function or class scope. The language reference has documented
1528 that this case is illegal, but the compiler never checked for it.
1529 The recent introduction of nested scope makes the meaning of this
1530 form of name binding ambiguous. In a future release, the compiler
1531 may allow this form when there is no possibility of ambiguity.
1532
Tim Peters40ead762001-01-27 05:35:26 +00001533- repr(string) is easier to read, now using hex escapes instead of octal,
1534 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1535
1536 >>> "\texample \r\n" + chr(0) + chr(255)
1537 '\texample \r\n\x00\xff' # in 2.1
1538 '\011example \015\012\000\377' # in 2.0
1539
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001540- Functions are now compared and hashed by identity, not by value, since
1541 the func_code attribute is writable.
1542
Fred Drakefb9d7122001-02-01 20:00:40 +00001543- Weak references (PEP 205) have been added. This involves a few
1544 changes in the core, an extension module (_weakref), and a Python
1545 module (weakref). The weakref module is the public interface. It
1546 includes support for "explicit" weak references, proxy objects, and
1547 mappings with weakly held values.
1548
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001549- A 'continue' statement can now appear in a try block within the body
1550 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001551 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001552
Tim Petersd7b5e882001-01-25 03:36:26 +00001553Standard library
1554
Barry Warsaw30dbd142001-01-31 22:14:01 +00001555- mailbox.py now has a new class, PortableUnixMailbox which is
1556 identical to UnixMailbox but uses a more portable scheme for
1557 determining From_ separators. Also, the constructors for all the
1558 classes in this module have a new optional `factory' argument, which
1559 is a callable used when new message classes must be instantiated by
1560 the next() method.
1561
Tim Petersd7b5e882001-01-25 03:36:26 +00001562- random.py is now self-contained, and offers all the functionality of
1563 the now-deprecated whrandom.py. See the docs for details. random.py
1564 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001565 and restoring the internal state of the generator; and jumpahead(n),
1566 for quickly forcing the internal state to be the same as if n calls to
1567 random() had been made. The latter is particularly useful for multi-
1568 threaded programs, creating one instance of the random.Random() class for
1569 each thread, then using .jumpahead() to force each instance to use a
1570 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001571
Tim Peters0de88fc2001-02-01 04:59:18 +00001572- random.py's seed() function is new. For bit-for-bit compatibility with
1573 prior releases, use the whseed function instead. The new seed function
1574 addresses two problems: (1) The old function couldn't produce more than
1575 about 2**24 distinct internal states; the new one about 2**45 (the best
1576 that can be done in the Wichmann-Hill generator). (2) The old function
1577 sometimes produced identical internal states when passed distinct
1578 integers, and there was no simple way to predict when that would happen;
1579 the new one guarantees to produce distinct internal states for all
1580 arguments in [0, 27814431486576L).
1581
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001582- The socket module now supports raw packets on Linux. The socket
1583 family is AF_PACKET.
1584
Tim Peters9ea17ac2001-02-02 05:57:15 +00001585- test_capi.py is a start at running tests of the Python C API. The tests
1586 are implemented by the new Modules/_testmodule.c.
1587
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001588- A new extension module, _symtable, provides provisional access to the
1589 internal symbol table used by the Python compiler. A higher-level
1590 interface will be added on top of _symtable in a future release.
1591
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001592- Removed the obsolete soundex module.
1593
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001594- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1595 the isSameNode method; NamedNodeMap the get method.
1596
1597- xml.sax.expatreader supports the lexical handler property; it
1598 generates comment, startCDATA, and endCDATA events.
1599
Tim Petersee826f82001-01-31 19:39:44 +00001600Windows changes
1601
1602- Build procedure: the zlib project is built in a different way that
1603 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001604 the zlib binary used. See PCbuild\readme.txt for details. Your old
1605 zlib-related directories can be deleted; you'll need to download fresh
1606 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001607
Tim Peters9ea17ac2001-02-02 05:57:15 +00001608- Build: New subproject _test for the benefit of test_capi.py (see above).
1609
Tim Petersb16c56f2001-02-02 21:24:51 +00001610- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1611 interface to some Python compiler internals).
1612
1613- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001614 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001615
Tim Petersa3a3a032000-11-30 05:22:44 +00001616What's New in Python 2.1 alpha 1?
1617=================================
1618
1619Core language, builtins, and interpreter
1620
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001621- There is a new Unicode companion to the PyObject_Str() API
1622 called PyObject_Unicode(). It behaves in the same way as the
1623 former, but assures that the returned value is an Unicode object
1624 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001625
Guido van Rossumf98eda02001-01-17 15:54:45 +00001626- The comparison operators support "rich comparison overloading" (PEP
1627 207). C extension types can provide a rich comparison function in
1628 the new tp_richcompare slot in the type object. The cmp() function
1629 and the C function PyObject_Compare() first try the new rich
1630 comparison operators before trying the old 3-way comparison. There
1631 is also a new C API PyObject_RichCompare() (which also falls back on
1632 the old 3-way comparison, but does not constrain the outcome of the
1633 rich comparison to a Boolean result).
1634
1635 The rich comparison function takes two objects (at least one of
1636 which is guaranteed to have the type that provided the function) and
1637 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1638 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1639 object, which may be NotImplemented (in which case the tp_compare
1640 slot function is used as a fallback, if defined).
1641
1642 Classes can overload individual comparison operators by defining one
1643 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001644 __ge__. There are no explicit "reflected argument" versions of
1645 these; instead, __lt__ and __gt__ are each other's reflection,
1646 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1647 reflection (similar at the C level). No other implications are
1648 made; in particular, Python does not assume that == is the Boolean
1649 inverse of !=, or that < is the Boolean inverse of >=. This makes
1650 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001651
1652 Classes or types that want to implement (in)equality tests but not
1653 the ordering operators (i.e. unordered types) should implement ==
1654 and !=, and raise an error for the ordering operators.
1655
Guido van Rossuma88479f2001-01-18 14:28:08 +00001656 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001657 Boolean; e.g. a matrix type might want to return a matrix of bits
1658 for A < B, giving elementwise comparisons. Such types should ensure
1659 that any interpretation of their value in a Boolean context raises
1660 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1661 at the C level) to always raise an exception.
1662
Guido van Rossuma88479f2001-01-18 14:28:08 +00001663- Complex numbers use rich comparisons to define == and != but raise
1664 an exception for <, <=, > and >=. Unfortunately, this also means
1665 that cmp() of two complex numbers raises an exception when the two
1666 numbers differ. Since it is not mathematically meaningful to compare
1667 complex numbers except for equality, I hope that this doesn't break
1668 too much code.
1669
Tim Peters3389f192001-02-18 08:48:49 +00001670- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001671 not defined by the language, other than that it's arbitrary but
1672 consistent (see the Reference Manual). An implementation detail changed
1673 in 2.1a1 such that None now compares less than any other object. Code
1674 relying on this new behavior (like code that relied on the previous
1675 behavior) does so at its own risk.
1676
Barry Warsaw573b5412001-01-15 20:43:18 +00001677- Functions and methods now support getting and setting arbitrarily
1678 named attributes (PEP 232). Functions have a new __dict__
1679 (a.k.a. func_dict) which hold the function attributes. Methods get
1680 and set attributes on their underlying im_func. It is a TypeError
1681 to set an attribute on a bound method.
1682
Guido van Rossum051e3352001-01-15 19:11:10 +00001683- The xrange() object implementation has been improved so that
1684 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1685 limitation that in this case len(xrange(sys.maxint)) can't be
1686 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1687 work fine as long as the index i doesn't actually reach 2**31.
1688 (Python uses regular ints for sequence and string indices; fixing
1689 that is much more work.)
1690
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001691- Two changes to from...import:
1692
Guido van Rossumba381232001-02-03 15:06:40 +00001693 1) "from M import X" now works even if (after loading module M)
1694 sys.modules['M'] is not a real module; it's basically a getattr()
1695 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001696
1697 2) "from M import *" now looks for M.__all__ to decide which names to
1698 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1699 filters out names starting with '_' as before. Whether or not
1700 __all__ exists, there's no restriction on the type of M.
1701
Guido van Rossumf61f1662001-01-10 20:13:55 +00001702- File objects have a new method, xreadlines(). This is the fastest
1703 way to iterate over all lines in a file:
1704
1705 for line in file.xreadlines():
1706 ...do something to line...
1707
1708 See the xreadlines module (mentioned below) for how to do this for
1709 other file-like objects.
1710
1711- Even if you don't use file.xreadlines(), you may expect a speedup on
1712 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001713 quite a bit in platform-specific ways: on systems (like Linux) that
1714 support flockfile(), getc_unlocked(), and funlockfile(), those are
1715 used by default. On systems (like Windows) without getc_unlocked(),
1716 a complicated (but still thread-safe) method using fgets() is used by
1717 default.
1718
Tim Petersd52269b2001-01-25 06:23:18 +00001719 You can force use of the fgets() method by #define'ing
1720 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001721 getc_unlocked()).
1722
Tim Petersd52269b2001-01-25 06:23:18 +00001723 You can force fgets() not to be used by #define'ing
1724 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001725 test_bufio.py fails -- and let us know if it does!).
1726
1727- In addition, the fileinput module, while still slower than the other
1728 methods on most platforms, has been sped up too, by using
1729 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001730
1731- Support for run-time warnings has been added, including a new
1732 command line option (-W) to specify the disposition of warnings.
1733 See the description of the warnings module below.
1734
1735- Extensive changes have been made to the coercion code. This mostly
1736 affects extension modules (which can now implement mixed-type
1737 numerical operators without having to use coercion), but
1738 occasionally, in boundary cases the coercion semantics have changed
1739 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001740 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001741 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001742 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001743
Guido van Rossumf98eda02001-01-17 15:54:45 +00001744- In connection with the coercion changes, a new built-in singleton
1745 object, NotImplemented is defined. This can be returned for
1746 operations that wish to indicate they are not implemented for a
1747 particular combination of arguments. From C, this is
1748 Py_NotImplemented.
1749
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001750- The interpreter accepts now bytecode files on the command line even
1751 if they do not have a .pyc or .pyo extension. On Linux, after executing
1752
Martin v. Löwise214baa2001-02-04 22:37:56 +00001753import imp,sys,string
1754magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1755reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1756open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001757
1758 any byte code file can be used as an executable (i.e. as an argument
1759 to execve(2)).
1760
Tim Peters9940b802000-12-01 07:59:35 +00001761- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001762 character. In 1.6 and earlier, they never produced a sign,
1763 and raised an error if the value of the long was too large
1764 to fit in a Python int. In 2.0, they produced a sign if and
1765 only if too large to fit in an int. This was inconsistent
1766 across platforms (because the size of an int varies across
1767 platforms), and inconsistent with hex() and oct(). Example:
1768
1769 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001770 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001771 'ffffffbe' # in 2.0 and before, on 32-bit machines
1772 >>> hex(-0x42L)
1773 '-0x42L' # in all versions of Python
1774
Tim Peters9940b802000-12-01 07:59:35 +00001775 The behavior of %d formats for negative Python longs remains
1776 the same as in 2.0 (although in 1.6 and before, they raised
1777 an error if the long didn't fit in a Python int).
1778
1779 %u formats don't make sense for Python longs, but are allowed
1780 and treated the same as %d in 2.1. In 2.0, a negative long
1781 formatted via %u produced a sign if and only if too large to
1782 fit in an int. In 1.6 and earlier, a negative long formatted
1783 via %u raised an error if it was too big to fit in an int.
1784
Guido van Rossum3661d392000-12-12 22:10:31 +00001785- Dictionary objects have an odd new method, popitem(). This removes
1786 an arbitrary item from the dictionary and returns it (in the form of
1787 a (key, value) pair). This can be useful for algorithms that use a
1788 dictionary as a bag of "to do" items and repeatedly need to pick one
1789 item. Such algorithms normally end up running in quadratic time;
1790 using popitem() they can usually be made to run in linear time.
1791
Tim Peters36cdad12000-12-29 02:06:45 +00001792Standard library
1793
Thomas Woutersfe385252001-01-19 23:16:56 +00001794- In the time module, the time argument to the functions strftime,
1795 localtime, gmtime, asctime and ctime is now optional, defaulting to
1796 the current time (in the local timezone).
1797
Guido van Rossumda91f222001-01-15 16:36:08 +00001798- The ftplib module now defaults to passive mode, which is deemed a
1799 more useful default given that clients are often inside firewalls
1800 these days. Note that this could break if ftplib is used to connect
1801 to a *server* that is inside a firewall, from outside; this is
1802 expected to be a very rare situation. To fix that, you can call
1803 ftp.set_pasv(0).
1804
Martin v. Löwis10a27872001-01-13 09:54:41 +00001805- The module site now treats .pth files not only for path configuration,
1806 but also supports extensions to the initialization code: Lines starting
1807 with import are executed.
1808
Guido van Rossumf61f1662001-01-10 20:13:55 +00001809- There's a new module, warnings, which implements a mechanism for
1810 issuing and filtering warnings. There are some new built-in
1811 exceptions that serve as warning categories, and a new command line
1812 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1813 turns warnings into errors). warnings.warn(message[, category])
1814 issues a warning message; this can also be called from C as
1815 PyErr_Warn(category, message).
1816
1817- A new module xreadlines was added. This exports a single factory
1818 function, xreadlines(). The intention is that this code is the
1819 absolutely fastest way to iterate over all lines in an open
1820 file(-like) object:
1821
1822 import xreadlines
1823 for line in xreadlines.xreadlines(file):
1824 ...do something to line...
1825
1826 This is equivalent to the previous the speed record holder using
1827 file.readlines(sizehint). Note that if file is a real file object
1828 (as opposed to a file-like object), this is equivalent:
1829
1830 for line in file.xreadlines():
1831 ...do something to line...
1832
Tim Peters36cdad12000-12-29 02:06:45 +00001833- The bisect module has new functions bisect_left, insort_left,
1834 bisect_right and insort_right. The old names bisect and insort
1835 are now aliases for bisect_right and insort_right. XXX_right
1836 and XXX_left methods differ in what happens when the new element
1837 compares equal to one or more elements already in the list: the
1838 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001839 right. Code that doesn't care where equal elements end up should
1840 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001841
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001842- The new curses.panel module wraps the panel library that forms part
1843 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1844
Guido van Rossumf61f1662001-01-10 20:13:55 +00001845- The SocketServer module now sets the allow_reuse_address flag by
1846 default in the TCPServer class.
1847
1848- A new function, sys._getframe(), returns the stack frame pointer of
1849 the caller. This is intended only as a building block for
1850 higher-level mechanisms such as string interpolation.
1851
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001852- The pyexpat module supports a number of new handlers, which are
1853 available only in expat 1.2. If invocation of a callback fails, it
1854 will report an additional frame in the traceback. Parser objects
1855 participate now in garbage collection. If expat reports an unknown
1856 encoding, pyexpat will try to use a Python codec; that works only
1857 for single-byte charsets. The parser type objects is exposed as
1858 XMLParserObject.
1859
1860- xml.dom now offers standard definitions for symbolic node type and
1861 exception code constants, and a hierarchy of DOM exceptions. minidom
1862 was adjusted to use them.
1863
1864- The conformance of xml.dom.minidom to the DOM specification was
1865 improved. It detects a number of additional error cases; the
1866 previous/next relationship works even when the tree is modified;
1867 Node supports the normalize() method; NamedNodeMap, DocumentType and
1868 DOMImplementation classes were added; Element supports the
1869 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1870 method.
1871
Guido van Rossumf61f1662001-01-10 20:13:55 +00001872Build issues
1873
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001874- For Unix (and Unix-compatible) builds, configuration and building of
1875 extension modules is now greatly automated. Rather than having to
1876 edit the Modules/Setup file to indicate which modules should be
1877 built and where their include files and libraries are, a
1878 distutils-based setup.py script now takes care of building most
1879 extension modules. All extension modules built this way are built
1880 as shared libraries. Only a few modules that must be linked
1881 statically are still listed in the Setup file; you won't need to
1882 edit their configuration.
1883
1884- Python should now build out of the box on Cygwin. If it doesn't,
1885 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001886
1887- Python now always uses its own (renamed) implementation of getopt()
1888 -- there's too much variation among C library getopt()
1889 implementations.
1890
1891- C++ compilers are better supported; the CXX macro is always set to a
1892 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001893
Tim Petersd92dfe02000-12-12 01:18:41 +00001894Windows changes
1895
1896- select module: By default under Windows, a select() call
1897 can specify no more than 64 sockets. Python now boosts
1898 this Microsoft default to 512. If you need even more than
1899 that, see the MS docs (you'll need to #define FD_SETSIZE
1900 and recompile Python from source).
1901
Guido van Rossumf61f1662001-01-10 20:13:55 +00001902- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1903 subdirectory is no more!
1904
Tim Petersa3a3a032000-11-30 05:22:44 +00001905
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001906What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001907=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001908
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001909Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001910changes are in the file HISTORY. If you are making the jump directly
1911from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1912HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001913
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001914Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1915the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1916http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001917
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001918--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001919
1920======================================================================
1921
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001922What's new in 2.0 (since release candidate 1)?
1923==============================================
1924
1925Standard library
1926
1927- The copy_reg module was modified to clarify its intended use: to
1928 register pickle support for extension types, not for classes.
1929 pickle() will raise a TypeError if it is passed a class.
1930
1931- Fixed a bug in gettext's "normalize and expand" code that prevented
1932 it from finding an existing .mo file.
1933
1934- Restored support for HTTP/0.9 servers in httplib.
1935
Tim Peters989b7b92000-10-16 20:24:53 +00001936- The math module was changed to stop raising OverflowError in case of
1937 underflow, and return 0 instead in underflow cases. Whether Python
1938 used to raise OverflowError in case of underflow was platform-
1939 dependent (it did when the platform math library set errno to ERANGE
1940 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001941
1942- Fixed a bug in StringIO that occurred when the file position was not
1943 at the end of the file and write() was called with enough data to
1944 extend past the end of the file.
1945
1946- Fixed a bug that caused Tkinter error messages to get lost on
1947 Windows. The bug was fixed by replacing direct use of
1948 interp->result with Tcl_GetStringResult(interp).
1949
1950- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1951 redirect response.
1952
1953- Several changes were made to distutils: Some debugging code was
1954 removed from util. Fixed the installer used when an external zip
1955 program (like WinZip) is not found; the source code for this
1956 installer is in Misc/distutils. check_lib() was modified to behave
1957 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1958 test for whether installed modules are on sys.path was changed to
1959 use both normcase() and normpath().
1960
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001961- Several minor bugs were fixed in the xml package (the minidom,
1962 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001963
1964- The regression test driver (regrtest.py) behavior when invoked with
1965 -l changed: It now reports a count of objects that are recognized as
1966 garbage but not freed by the garbage collector.
1967
Tim Peters989b7b92000-10-16 20:24:53 +00001968- The regression test for the math module was changed to test
1969 exceptional behavior when the test is run in verbose mode. Python
1970 cannot yet guarantee consistent exception behavior across platforms,
1971 so the exception part of test_math is run only in verbose mode, and
1972 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001973
1974Internals
1975
1976- PyOS_CheckStack() has been disabled on Win64, where it caused
1977 test_sre to fail.
1978
1979Build issues
1980
1981- Changed compiler flags, so that gcc is always invoked with -Wall and
1982 -Wstrict-prototypes. Users compiling Python with GCC should see
1983 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001984 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001985 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001986
Tim Petersa3a3a032000-11-30 05:22:44 +00001987- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001988
1989Tools and other miscellany
1990
1991- The compiler in Tools/compiler was updated to support the new
1992 language features introduced in 2.0: extended print statement, list
1993 comprehensions, and augmented assignments. The new compiler should
1994 also be backwards compatible with Python 1.5.2; the compiler will
1995 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001996 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001997
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001998What's new in 2.0 release candidate 1 (since beta 2)?
1999=====================================================
2000
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002001What is release candidate 1?
2002
2003We believe that release candidate 1 will fix all known bugs that we
2004intend to fix for the 2.0 final release. This release should be a bit
2005more stable than the previous betas. We would like to see even more
2006widespread testing before the final release, so we are producing this
2007release candidate. The final release will be exactly the same unless
2008any show-stopping (or brown bag) bugs are found by testers of the
2009release candidate.
2010
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002011All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002012to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002013
2014Core language, builtins, and interpreter
2015
2016- A bug that caused crashes when __coerce__ was used with augmented
2017 assignment, e.g. +=, was fixed.
2018
2019- Raise ZeroDivisionError when raising zero to a negative number,
2020 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2021 power operator and the result of math.pow(0.0, -2.0) will vary by
2022 platform. On Linux, it raises a ValueError.
2023
2024- A bug in Unicode string interpolation was fixed that occasionally
2025 caused errors with formats including "%%". For example, the
2026 following expression "%% %s" % u"abc" no longer raises a TypeError.
2027
2028- Compilation of deeply nested expressions raises MemoryError instead
2029 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2030
2031- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2032 rendering them useless. They are now written in binary mode again.
2033
2034Standard library
2035
2036- Keyword arguments are now accepted for most pattern and match object
2037 methods in SRE, the standard regular expression engine.
2038
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002039- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002040 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002041
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002042- Several bugs in the Unicode handling and error handling in _tkinter
2043 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002044
2045- Fix memory management errors in Merge() and Tkapp_Call() routines.
2046
2047- Several changes were made to cStringIO to make it compatible with
2048 the file-like object interface and with StringIO. If operations are
2049 performed on a closed object, an exception is raised. The truncate
2050 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002051 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002052
2053- There were many changes made to the linuxaudiodev module and its
2054 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002055 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002056
2057 Note that this module is named poorly, because it should work
2058 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002059 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002060
2061 The module now raises exceptions when errors occur instead of
2062 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2063 audio) and defines a getptr() method that calls the
2064 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2065
2066- The library_version attribute, introduced in an earlier beta, was
2067 removed because it can not be supported with early versions of the C
2068 readline library, which provides no way to determine the version at
2069 compile-time.
2070
2071- The binascii module is now enabled on Win64.
2072
Tim Peters46446d62000-10-09 21:19:31 +00002073- tokenize.py no longer suffers "recursion depth" errors when parsing
2074 programs with very long string literals.
2075
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002076Internals
2077
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002078- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002079 which is called when the interpreter starts up to determine where
2080 the standard library is installed. These vulnerabilities affect all
2081 previous versions of Python and can be exploited by setting very
2082 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2083 setuid Python script, although use of the wrapper in
2084 Misc/setuid-prog.c will eliminate the vulnerability.
2085
2086- Fixed garbage collection bugs in instance creation that were
2087 triggered when errors occurred during initialization. The solution,
2088 applied in cPickle and in PyInstance_New(), is to call
2089 PyObject_GC_Init() after the initialization of the object's
2090 container attributes is complete.
2091
2092- pyexpat adds definitions of PyModule_AddStringConstant and
2093 PyModule_AddObject if the Python version is less than 2.0, which
2094 provides compatibility with PyXML on Python 1.5.2.
2095
2096- If the platform has a bogus definition for LONG_BIT (the number of
2097 bits in a long), an error will be reported at compile time.
2098
2099- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2100 collection crashes and possibly other, unreported crashes.
2101
2102- Fixed a memory leak in _PyUnicode_Fini().
2103
2104Build issues
2105
2106- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002107 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002108 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002109
2110- The mmap.PAGESIZE constant is now initialized using sysconf when
2111 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2112
2113- The md5 file should now compile on all platforms.
2114
2115- The select module now compiles on platforms that do not define
2116 POLLRDNORM and related constants.
2117
2118- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002119 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002120
Jeremy Hylton10921202000-10-09 18:34:12 +00002121- BeOS: A number of changes were made to the build and installation
2122 process. ar-fake now operates on a directory of object files.
2123 dl_export.h is gone, and its macros now appear on the mwcc command
2124 line during build on PPC BeOS.
2125
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002126- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002127 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002128
2129- Cygwin: Support for shared libraries, Tkinter, and sockets.
2130
2131- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2132
2133Tools and other miscellany
2134
2135- Removed debugging prints from main used with freeze.
2136
Tim Peters46446d62000-10-09 21:19:31 +00002137- IDLE auto-indent no longer crashes when it encounters Unicode
2138 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002139
2140What's new in 2.0 beta 2 (since beta 1)?
2141========================================
2142
2143Core language, builtins, and interpreter
2144
Tim Peters482c0212000-09-26 06:33:09 +00002145- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002146 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002147
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002148- Add -h and -V command line options to print the usage message and
2149 Python version number and exit immediately.
2150
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002151- eval() and exec accept Unicode objects as code parameters.
2152
2153- getattr() and setattr() now also accept Unicode objects for the
2154 attribute name, which are converted to strings using the default
2155 encoding before lookup.
2156
2157- Multiplication on string and Unicode now does proper bounds
2158 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2159 string is too long."
2160
2161- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002162 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002163
Jeremy Hylton1b618592000-09-26 05:32:36 +00002164
2165Standard library and extensions
2166
Guido van Rossum5b08f132001-04-16 02:05:23 +00002167- socket module: the OpenSSL code now adds support for RAND_status()
2168 and EGD (Entropy Gathering Device).
2169
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002170- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002171 argument checking; it still takes no arguments.
2172
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002173- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002174
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002175- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002176
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002177- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002178
2179- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002180 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002181
2182- copy: Copy Unicode objects atomically.
2183
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002184- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002185
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002186- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002187
Fred Drake67233bc2000-09-26 16:40:27 +00002188- dbm: Add get() and setdefault() methods to dbm object. Add constant
2189 `library' to module that names the library used. Added doc strings
2190 and method names to error messages. Uses configure to determine
2191 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2192 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002193
2194- distutils: Update to version 0.9.3.
2195
2196- dl: Add several dl.RTLD_ constants.
2197
2198- fpectl: Now supported on FreeBSD.
2199
2200- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2201 found by the collector will be saved in gc.garbage. This is useful
2202 for debugging a program that creates reference cycles.
2203
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002204- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002205 of HTTP class. Do not close socket on zero-length response. Do not
2206 crash when server sends invalid content-length header.
2207
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002208- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002209
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002210- marshal: When reading a short, sign-extend on platforms where shorts
2211 are bigger than 16 bits. When reading a long, repair the unportable
2212 sign extension that was being done for 64-bit machines. (It assumed
2213 that signed right shift sign-extends.)
2214
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002215- operator: Add contains(), invert(), __invert__() as aliases for
2216 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002217
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002218- os: Add support for popen2() and popen3() on all platforms where
2219 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002220
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002221- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002222 clicking on a file in Explorer (or passing the file name to the
2223 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002224
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002225- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002226 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002227
2228- pickle: Now raises ValueError when an invalid pickle that contains
2229 a non-string repr where a string repr was expected. This behavior
2230 matches cPickle.
2231
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002232- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002233
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002234- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002235
2236- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002237 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002238 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002239
2240- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002241 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002242
2243- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002244 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002245 few cycles during startup since the first call to
2246 setdefaultencoding() will initialize the codec registry and the
2247 encodings package.
2248
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002249- socket: Support for size hint in readlines() method of object returned
2250 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002251
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002252- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002253 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002254 is followed by whitespace.
2255
Tim Petersa3a3a032000-11-30 05:22:44 +00002256- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002257
2258- struct: Check ranges for bytes and shorts.
2259
2260- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002261 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002262
2263- Tkinter: Image objects are now guaranteed to have unique ids. Set
2264 event.delta to zero if Tk version doesn't support mousewheel.
2265 Removed some debugging prints.
2266
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002267- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002268
Fred Drake67233bc2000-09-26 16:40:27 +00002269- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002270 which works around a bug in Norton AntiVirus 2000 that leads directly
2271 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002272
2273- xml: New version detection code allows PyXML to override standard
2274 XML package if PyXML version is greater than 0.6.1.
2275
Fred Drake64bb3802000-09-26 16:21:35 +00002276- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2277 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2278 tree only for nodes which are sufficiently interesting to a specific
2279 application. Does not provide the HTML-specific extensions. Still
2280 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002281
Fred Drake64bb3802000-09-26 16:21:35 +00002282- xml.sax: SAX 2 support for Python, including all the handler
2283 interfaces needed to process XML 1.0 compliant XML. Some
2284 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002285
Fred Drake64bb3802000-09-26 16:21:35 +00002286- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2287 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002288
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002289
Jeremy Hylton1b618592000-09-26 05:32:36 +00002290C API
2291
2292- Add three new convenience functions for module initialization --
2293 PyModule_AddObject(), PyModule_AddIntConstant(), and
2294 PyModule_AddStringConstant().
2295
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002296- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002297 removed and add #error to Python.h if NULL isn't defined after
2298 #include of stdio.h.
2299
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002300- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002301 backwards compatibility (at the source level) with old extensions.
2302
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002303- A wrapper API was added for signal() and sigaction(). Instead of
2304 either function, always use PyOS_getsig() to get a signal handler
2305 and PyOS_setsig() to set one. A new convenience typedef
2306 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002307
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002308- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002309 internal data buffer and size of a string object -- or the default
2310 encoded version of a Unicode object.
2311
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002312- PyString_Size() and PyString_AsString() accept Unicode objects.
2313
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002314- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002315 exists). INT_MAX and LONG_MAX will always be defined, even if
2316 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002317
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002318- PyFloat_FromString takes a second argument, pend, that was
2319 effectively useless. It is now officially useless but preserved for
2320 backwards compatibility. If the pend argument is not NULL, *pend is
2321 set to NULL.
2322
2323- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2324 for the attribute name. See note on getattr() above.
2325
2326- A few bug fixes to argument processing for Unicode.
2327 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2328 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2329 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002330 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002331
2332- Py_BuildValue accepts B format (for bgen-generated code).
2333
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002334
Jeremy Hylton1b618592000-09-26 05:32:36 +00002335Internals
2336
2337- On Unix, fix code for finding Python installation directory so that
2338 it works when argv[0] is a relative path.
2339
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002340- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002341 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002342 rather than by generating a copy of the object.
2343
Tim Peters482c0212000-09-26 06:33:09 +00002344- Several of the internal Unicode tables are much smaller now, and
2345 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002346
Jeremy Hylton97693b02000-09-26 17:42:51 +00002347- In the garbage collector: Fixed bug in collection of tuples. Fixed
2348 bug that caused some instances to be removed from the container set
2349 while they were still live. Fixed parsing in gc.set_debug() for
2350 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002351
2352- Fixed refcount problem in instance deallocation that only occurred
2353 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2354
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002355- On Windows, getpythonregpath is now protected against null data in
2356 registry key.
2357
2358- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002359 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002360
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002361
Jeremy Hylton1b618592000-09-26 05:32:36 +00002362Build and platform-specific issues
2363
2364- Better support of GNU Pth via --with-pth configure option.
2365
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002366- Python/C API now properly exposed to dynamically-loaded extension
2367 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002368
2369- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2370 Don't define MS_SYNC to be zero when it is undefined. Added missing
2371 prototypes in posixmodule.c.
2372
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002373- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002374 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002375
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002376- Fix largefile support on older NetBSD systems and OpenBSD by adding
2377 define for TELL64.
2378
2379
2380Tools and other miscellany
2381
2382- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2383
2384- freeze: The modulefinder now works with 2.0 opcodes.
2385
Tim Petersa3a3a032000-11-30 05:22:44 +00002386- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002387 Move hackery of sys.argv until after the Tk instance has been
2388 created, which allows the application-specific Tkinter
2389 initialization to be executed if present; also pass an explicit
2390 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002391
Jeremy Hylton1b618592000-09-26 05:32:36 +00002392
2393What's new in 2.0 beta 1?
2394=========================
2395
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002396Source Incompatibilities
2397------------------------
2398
2399None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2400such as single-argument append(), connect() and bind(), and changes to
2401str(long) and repr(float).
2402
2403
2404Binary Incompatibilities
2405------------------------
2406
2407- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2408with Python 2.0; these extensions will have to be rebuilt for Python
24092.0.
2410
2411- On Windows, attempting to import a third party extension built for
2412Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2413can do about this. Check your PYTHONPATH environment variable!
2414
2415- Python bytecode files (*.pyc and *.pyo) are not compatible between
2416releases.
2417
2418
2419Overview of Changes Since 1.6
2420-----------------------------
2421
2422There are many new modules (including brand new XML support through
2423the xml package, and i18n support through the gettext module); a list
2424of all new modules is included below. Lots of bugs have been fixed.
2425
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002426The process for making major new changes to the language has changed
2427since Python 1.6. Enhancements must now be documented by a Python
2428Enhancement Proposal (PEP) before they can be accepted.
2429
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002430There are several important syntax enhancements, described in more
2431detail below:
2432
2433 - Augmented assignment, e.g. x += 1
2434
2435 - List comprehensions, e.g. [x**2 for x in range(10)]
2436
2437 - Extended import statement, e.g. import Module as Name
2438
2439 - Extended print statement, e.g. print >> file, "Hello"
2440
2441Other important changes:
2442
2443 - Optional collection of cyclical garbage
2444
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002445Python Enhancement Proposal (PEP)
2446---------------------------------
2447
2448PEP stands for Python Enhancement Proposal. A PEP is a design
2449document providing information to the Python community, or describing
2450a new feature for Python. The PEP should provide a concise technical
2451specification of the feature and a rationale for the feature.
2452
2453We intend PEPs to be the primary mechanisms for proposing new
2454features, for collecting community input on an issue, and for
2455documenting the design decisions that have gone into Python. The PEP
2456author is responsible for building consensus within the community and
2457documenting dissenting opinions.
2458
2459The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002460
2461Augmented Assignment
2462--------------------
2463
2464This must have been the most-requested feature of the past years!
2465Eleven new assignment operators were added:
2466
Guido van Rossume905e952000-09-05 12:42:46 +00002467 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002468
2469For example,
2470
2471 A += B
2472
2473is similar to
2474
2475 A = A + B
2476
2477except that A is evaluated only once (relevant when A is something
2478like dict[index].attr).
2479
2480However, if A is a mutable object, A may be modified in place. Thus,
2481if A is a number or a string, A += B has the same effect as A = A+B
2482(except A is only evaluated once); but if a is a list, A += B has the
2483same effect as A.extend(B)!
2484
2485Classes and built-in object types can override the new operators in
2486order to implement the in-place behavior; the not-in-place behavior is
2487used automatically as a fallback when an object doesn't implement the
2488in-place behavior. For classes, the method name is derived from the
2489method name for the corresponding not-in-place operator by inserting
2490an 'i' in front of the name, e.g. __iadd__ implements in-place
2491__add__.
2492
2493Augmented assignment was implemented by Thomas Wouters.
2494
2495
2496List Comprehensions
2497-------------------
2498
2499This is a flexible new notation for lists whose elements are computed
2500from another list (or lists). The simplest form is:
2501
2502 [<expression> for <variable> in <sequence>]
2503
Guido van Rossum56db0952000-09-06 23:34:25 +00002504For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002505This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002506
2507You can also add a condition:
2508
2509 [<expression> for <variable> in <sequence> if <condition>]
2510
2511For example, [w for w in words if w == w.lower()] would yield the list
2512of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002513than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002514
2515You can also have nested for loops and more than one 'if' clause. For
2516example, here's a function that flattens a sequence of sequences::
2517
2518 def flatten(seq):
2519 return [x for subseq in seq for x in subseq]
2520
2521 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2522
2523This prints
2524
2525 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2526
2527List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002528Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002529
2530
2531Extended Import Statement
2532-------------------------
2533
2534Many people have asked for a way to import a module under a different
2535name. This can be accomplished like this:
2536
2537 import foo
2538 bar = foo
2539 del foo
2540
2541but this common idiom gets old quickly. A simple extension of the
2542import statement now allows this to be written as follows:
2543
2544 import foo as bar
2545
2546There's also a variant for 'from ... import':
2547
2548 from foo import bar as spam
2549
2550This also works with packages; e.g. you can write this:
2551
2552 import test.regrtest as regrtest
2553
2554Note that 'as' is not a new keyword -- it is recognized only in this
2555context (this is only possible because the syntax for the import
2556statement doesn't involve expressions).
2557
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002558Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002559
2560
2561Extended Print Statement
2562------------------------
2563
2564Easily the most controversial new feature, this extension to the print
2565statement adds an option to make the output go to a different file
2566than the default sys.stdout.
2567
2568For example, to write an error message to sys.stderr, you can now
2569write:
2570
2571 print >> sys.stderr, "Error: bad dog!"
2572
2573As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002574evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002575
2576 print >> None, "Hello world"
2577
2578is equivalent to
2579
2580 print "Hello world"
2581
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002582Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002583
2584
2585Optional Collection of Cyclical Garbage
2586---------------------------------------
2587
2588Python is now equipped with a garbage collector that can hunt down
2589cyclical references between Python objects. It's no replacement for
2590reference counting; in fact, it depends on the reference counts being
2591correct, and decides that a set of objects belong to a cycle if all
2592their reference counts can be accounted for from their references to
2593each other. This devious scheme was first proposed by Eric Tiedemann,
2594and brought to implementation by Neil Schemenauer.
2595
2596There's a module "gc" that lets you control some parameters of the
2597garbage collection. There's also an option to the configure script
2598that lets you enable or disable the garbage collection. In 2.0b1,
2599it's on by default, so that we (hopefully) can collect decent user
2600experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002601performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002602off by default in the final 2.0 release.
2603
2604
2605Smaller Changes
2606---------------
2607
2608A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2609map(None, seq1, seq2, ...) when the sequences have the same length;
2610i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2611the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002612zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002613
2614sys.version_info is a tuple (major, minor, micro, level, serial).
2615
2616Dictionaries have an odd new method, setdefault(key, default).
2617dict.setdefault(key, default) returns dict[key] if it exists; if not,
2618it sets dict[key] to default and returns that value. Thus:
2619
2620 dict.setdefault(key, []).append(item)
2621
2622does the same work as this common idiom:
2623
2624 if not dict.has_key(key):
2625 dict[key] = []
2626 dict[key].append(item)
2627
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002628There are two new variants of SyntaxError that are raised for
2629indentation-related errors: IndentationError and TabError.
2630
2631Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2632escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002633
2634The limits on the size of expressions and file in Python source code
2635have been raised from 2**16 to 2**32. Previous versions of Python
2636were limited because the maximum argument size the Python VM accepted
2637was 2**16. This limited the size of object constructor expressions,
2638e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2639limit was raised thanks to a patch by Charles Waldman that effectively
2640fixes the problem. It is now much more likely that you will be
2641limited by available memory than by an arbitrary limit in Python.
2642
2643The interpreter's maximum recursion depth can be modified by Python
2644programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2645limit is the maximum number of recursive calls that can be made by
2646Python code. The limit exists to prevent infinite recursion from
2647overflowing the C stack and causing a core dump. The default value is
26481000. The maximum safe value for a particular platform can be found
2649by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002650
2651New Modules and Packages
2652------------------------
2653
2654atexit - for registering functions to be called when Python exits.
2655
2656imputil - Greg Stein's alternative API for writing custom import
2657hooks.
2658
2659pyexpat - an interface to the Expat XML parser, contributed by Paul
2660Prescod.
2661
2662xml - a new package with XML support code organized (so far) in three
2663subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2664would fill a volume. There's a special feature whereby a
2665user-installed package named _xmlplus overrides the standard
2666xmlpackage; this is intended to give the XML SIG a hook to distribute
2667backwards-compatible updates to the standard xml package.
2668
2669webbrowser - a platform-independent API to launch a web browser.
2670
2671
Guido van Rossume905e952000-09-05 12:42:46 +00002672Changed Modules
2673---------------
2674
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002675array -- new methods for array objects: count, extend, index, pop, and
2676remove
2677
2678binascii -- new functions b2a_hex and a2b_hex that convert between
2679binary data and its hex representation
2680
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002681calendar -- Many new functions that support features including control
2682over which day of the week is the first day, returning strings instead
2683of printing them. Also new symbolic constants for days of week,
2684e.g. MONDAY, ..., SUNDAY.
2685
2686cgi -- FieldStorage objects have a getvalue method that works like a
2687dictionary's get method and returns the value attribute of the object.
2688
2689ConfigParser -- The parser object has new methods has_option,
2690remove_section, remove_option, set, and write. They allow the module
2691to be used for writing config files as well as reading them.
2692
2693ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002694optionally support the RFC 959 REST command.
2695
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002696gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002697
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002698httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2699the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002700
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002701locale -- implement getdefaultlocale for Win32 and Macintosh
2702
2703marshal -- no longer dumps core when marshaling deeply nested or
2704recursive data structures
2705
2706os -- new functions isatty, seteuid, setegid, setreuid, setregid
2707
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002708os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2709support under Unix.
2710
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002711os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002712
2713os.path -- fix semantics of os.path.commonprefix
2714
2715smtplib -- support for sending very long messages
2716
2717socket -- new function getfqdn()
2718
2719readline -- new functions to read, write and truncate history files.
2720The readline section of the library reference manual contains an
2721example.
2722
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002723select -- add interface to poll system call
2724
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002725shutil -- new copyfileobj function
2726
2727SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2728HTTP server.
2729
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002730Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002731
2732urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002733e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002734
2735whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002736
2737
2738Obsolete Modules
2739----------------
2740
2741None. However note that 1.6 made a whole slew of modules obsolete:
2742stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2743poly, zmod, strop, util, whatsound.
2744
2745
2746Changed, New, Obsolete Tools
2747----------------------------
2748
Tim Peters8b092332000-09-05 20:15:25 +00002749None.
Guido van Rossume905e952000-09-05 12:42:46 +00002750
2751
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002752C-level Changes
2753---------------
2754
2755Several cleanup jobs were carried out throughout the source code.
2756
2757All C code was converted to ANSI C; we got rid of all uses of the
2758Py_PROTO() macro, which makes the header files a lot more readable.
2759
2760Most of the portability hacks were moved to a new header file,
2761pyport.h; several other new header files were added and some old
2762header files were removed, in an attempt to create a more rational set
2763of header files. (Few of these ever need to be included explicitly;
2764they are all included by Python.h.)
2765
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002766Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002767and Win64, especially for the new Intel Itanium processor. Mick also
2768added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002769
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002770The C APIs to return an object's size have been update to consistently
2771use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2772previous versions, the abstract interfaces used PyXXX_Length and the
2773concrete interfaces used PyXXX_Size. The old names,
2774e.g. PyObject_Length, are still available for backwards compatibility
2775at the API level, but are deprecated.
2776
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002777The PyOS_CheckStack function has been implemented on Windows by
2778Fredrik Lundh. It prevents Python from failing with a stack overflow
2779on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002780
2781The GC changes resulted in creation of two new slots on object,
2782tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002783the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002784
2785The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002786C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002787
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002788PyErr_Format has been updated to automatically calculate the size of
2789the buffer needed to hold the formatted result string. This change
2790prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002791
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002792New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002793
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002794PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2795that are the same as their non-Ex counterparts except they take an
2796extra flag argument that tells them to close the file when done.
2797
2798XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002799
Tim Peters8b092332000-09-05 20:15:25 +00002800
2801Windows Changes
2802---------------
2803
2804New popen2/popen3/peopen4 in os module (see Changed Modules above).
2805
2806os.popen is much more usable on Windows 95 and 98. See Microsoft
2807Knowledge Base article Q150956. The Win9x workaround described there
2808is implemented by the new w9xpopen.exe helper in the root of your
2809Python installation. Note that Python uses this internally; it is not
2810a standalone program.
2811
2812Administrator privileges are no longer required to install Python
2813on Windows NT or Windows 2000. If you have administrator privileges,
2814Python's registry info will be written under HKEY_LOCAL_MACHINE.
2815Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002816under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002817uses of Python, but will prevent some advanced uses from working
2818(for example, running a Python script as an NT service, or possibly
2819from CGI).
2820
2821[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2822installer; instead, it installs the needed Tcl/Tk files directly in the
2823Python directory. If you already have a Tcl/Tk installation, this
2824wastes some disk space (about 4 Megs) but avoids problems with
2825conflicting Tcl/Tk installations, and makes it much easier for Python
2826to ensure that Tcl/Tk can find all its files.
2827
2828[This was new in 1.6] The Windows installer now installs by default in
2829\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2830
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002831
2832Updates to the changes between 1.5.2 and 1.6
2833--------------------------------------------
2834
2835The 1.6 NEWS file can't be changed after the release is done, so here
2836is some late-breaking news:
2837
2838New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2839and changes to getlocale() and setlocale().
2840
2841The new module is now enabled per default.
2842
2843It is not true that the encodings codecs cannot be used for normal
2844strings: the string.encode() (which is also present on 8-bit strings
2845!) allows using them for 8-bit strings too, e.g. to convert files from
2846cp1252 (Windows) to latin-1 or vice-versa.
2847
2848Japanese codecs are available from Tamito KAJIYAMA:
2849http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2850
2851
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002852======================================================================