blob: 4fc5c1d8094fe018c7771083f785dd79cc9bf83b [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 Rossumc8e56452001-10-22 00:43:43 +00007- Methods of built-in types now properly check for keyword arguments
8 (formerly these were silently ignored). The only built-in methods
9 that take keyword arguments are __call__, __init__ and __new__.
10
Tim Peters84362bc2001-10-19 17:55:30 +000011Core and builtins
12
13Extension modules
14
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000015- Various bugfixes to the curses module.
16
Tim Peters84362bc2001-10-19 17:55:30 +000017Library
18
Tim Peters98791af2001-10-23 01:59:54 +000019- Traceback objects are now scanned by cyclic garbage collection, so
20 cycles created by casual use of sys.exc_info() no longer cause
21 permanent memory leaks (provided garbage collection is enabled).
22
Tim Peters84362bc2001-10-19 17:55:30 +000023Tools/Demos
24
25Build
26
27C API
28
29New platforms
30
31Tests
32
Andrew M. Kuchling15e03532001-10-22 16:37:10 +000033- Added a test script for the curses module. It isn't run automatically;
34 regrtest.py must be run with '-u curses' to enable it.
35
Tim Peters84362bc2001-10-19 17:55:30 +000036Windows
37
38
Tim Petersabf925f2001-09-28 21:53:42 +000039What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +000040Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +000041===========================
42
43Type/class unification and new-style classes
44
Guido van Rossum687ae002001-10-15 22:03:32 +000045- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +000046 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +000047 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +000048 remains: the __dict__ of a new-style class is a read-only proxy; you
49 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +000050 __defined__ attribute of new-style types no longer exists, for lack
51 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +000052 future a __cache__ may be resurrected with a similar function, if I
53 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +000054
Tim Peters1c9ca872001-10-04 06:43:12 +000055- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
56 always returned None, even when there was a class docstring).
57
58- doctest now finds and runs docstrings attached to new-style classes,
59 class methods, static methods, and properties.
60
Guido van Rossum9074ef62001-10-16 21:34:49 +000061Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +000062
Guido van Rossuma8bcf802001-10-15 15:53:58 +000063- A very subtle syntactical pitfall in list comprehensions was fixed.
64 For example: [a+b for a in 'abc', for b in 'def']. The comma in
65 this example is a mistake. Previously, this would silently let 'a'
66 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
67 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
68 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
69 Note that [a for a in <singleton>] is a convoluted way to say
70 [<singleton>] anyway, so it's not like any expressiveness is lost.
71
Guido van Rossum9074ef62001-10-16 21:34:49 +000072- getattr(obj, name, default) now only catches AttributeError, as
73 documented, rather than returning the default value for all
74 exceptions (which could mask bugs in a __getattr__ hook, for
75 example).
76
Fred Drakecb7a6b52001-10-22 18:41:51 +000077- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +000078 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +000079 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +000080 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +000081
Guido van Rossum1c486092001-10-19 02:05:35 +000082- unicode(obj) now behaves more like str(obj), accepting arbitrary
83 objects, and calling a __unicode__ method if it exists.
84 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +000085 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +000086
Barry Warsawf6fb1712001-10-19 05:35:40 +000087- isinstance() now allows any object as the first argument and a
88 class, a type or something with a __bases__ tuple attribute for the
89 second argument. The second argument may also be a tuple of a
90 class, type, or something with __bases__, in which case isinstance()
91 will return true if the first argument is an instance of any of the
92 things contained in the second argument tuple. E.g.
93
94 isinstance(x, (A, B))
95
96 returns true if x is an instance of A or B.
97
Guido van Rossum9074ef62001-10-16 21:34:49 +000098Extension modules
99
100- thread.start_new_thread() now returns the thread ID (previously None).
101
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000102- binascii has now two quopri support functions, a2b_qp and b2a_qp.
103
Guido van Rossumc524d952001-10-19 01:31:59 +0000104- readline now supports setting the startup_hook and the
105 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000106
Guido van Rossumc524d952001-10-19 01:31:59 +0000107- os and posix supports chroot(), setgroups() and unsetenv() where
108 available. The stat(), fstat(), statvfs() and fstatvfs() functions
109 now return "pseudo-sequences" -- the various fields can now be
110 accessed as attributes (e.g. os.stat("/").st_mtime) but for
111 backwards compatibility they also behave as a fixed-length sequence.
112 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000113 attributes.
114
115- time: localtime(), gmtime() and strptime() now return a
116 pseudo-sequence similar to the os.stat() return value, with
117 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000118
Guido van Rossum9074ef62001-10-16 21:34:49 +0000119- Decompression objects in the zlib module now accept an optional
120 second parameter to decompress() that specifies the maximum amount
121 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000122
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000123- optional SSL support in the socket module now exports OpenSSL
124 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
125 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000126 automatically seed its PRNG. Also, the keyfile and certfile
127 arguments to socket.ssl() are now optional.
128
129- posixmodule (and by extension, the os module on POSIX platforms) now
130 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000131
Guido van Rossum9074ef62001-10-16 21:34:49 +0000132Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000133
Tim Peters7402f792001-10-02 03:53:41 +0000134- doctest now excludes functions and classes not defined by the module
135 being tested, thanks to Tim Hochberg.
136
Fred Drakecb7a6b52001-10-22 18:41:51 +0000137- HotShot, a new profiler implemented using a C-based callback, has
138 been added. This substantially reduces the overhead of profiling,
139 but it is still quite preliminary. Support modules and
140 documentation will be added in upcoming releases (before 2.2 final).
141
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000142- profile now produces correct output in situations where an exception
143 raised in Python is cleared by C code (e.g. hasattr()). This used
144 to cause wrong output, including spurious claims of recursive
145 functions and attribution of time spent to the wrong function.
146
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000147 The code and documentation for the derived OldProfile and HotProfile
148 profiling classes was removed. The code hasn't worked for years (if
149 you tried to use them, they raised exceptions). OldProfile
150 intended to reproduce the behavior of the profiler Python used more
151 than 7 years ago, and isn't interesting anymore. HotProfile intended
152 to provide a faster profiler (but producing less information), and
153 that's a worthy goal we intend to meet via a different approach (but
154 without losing information).
155
Tim Peterscce092d2001-10-09 05:31:56 +0000156- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000157 a much better system-specific calibration constant. The constant can
158 now be specified in an instance constructor, or as a Profile class or
159 instance variable, instead of by editing profile.py's source code.
160 Calibration must still be done manually (see the docs for the profile
161 module).
162
163 Note that Profile.calibrate() must be overriden by subclasses.
164 Improving the accuracy required exploiting detailed knowledge of
165 profiler internals; the earlier method abstracted away the details
166 and measured a simplified model instead, but consequently computed
167 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000168
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000169- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000170 which indicates whether output is intended for the header 'Q'
171 encoding.
172
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000173- The SocketServer.ThreadingMixIn class now closes the request after
174 finish_request() returns. (Not when it errors out though.)
175
Barry Warsawf6fb1712001-10-19 05:35:40 +0000176- The nntplib module's NNTP.body() method has grown a `file' argument
177 to allow saving the message body to a file.
178
179- The email package has added a class email.Parser.HeaderParser which
180 only parses headers and does not recurse into the message's body.
181 Also, the module/class MIMEAudio has been added for representing
182 audio data (contributed by Anthony Baxter).
183
184- ftplib should be able to handle files > 2GB.
185
186- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
187 ON, and OFF.
188
Fred Drakecb7a6b52001-10-22 18:41:51 +0000189- xml.dom.minidom NodeList objects now support the length attribute
190 and item() method as required by the DOM specifications.
191
Guido van Rossumed554f62001-10-02 23:15:37 +0000192Tools/Demos
193
194- Demo/dns was removed. It no longer serves any purpose; a package
195 derived from it is now maintained by Anthony Baxter, see
196 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000197
Barry Warsawf6fb1712001-10-19 05:35:40 +0000198- The freeze tool has been made more robust, and two new options have
199 been added: -X and -E.
200
Tim Petersabf925f2001-09-28 21:53:42 +0000201Build
202
Barry Warsawf6fb1712001-10-19 05:35:40 +0000203- configure will use CXX in LINKCC if CXX is used to build main() and
204 the system requires to link a C++ main using the C++ compiler.
205
Tim Petersabf925f2001-09-28 21:53:42 +0000206C API
207
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000208- The documentation for the tp_compare slot is updated to require that
209 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
210 not correct. This is not yet enforced but will be enforced in
211 Python 2.3; even later, we may use -2 to indicate errors and +2 for
212 "NotImplemented". Right now, -1 should be used for an error return.
213
Tim Petersd38b1c72001-09-30 05:09:37 +0000214- PyLong_AsLongLong() now accepts int (as well as long) arguments.
215 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
216 as long) arguments.
217
Guido van Rossum3c288632001-10-16 21:13:49 +0000218- PyThread_start_new_thread() now returns a long int giving the thread
219 ID, if one can be calculated; it returns -1 for error, 0 if no
220 thread ID is calculated (this is an incompatible change, but only
221 the thread module used this API). This code has only really been
222 tested on Linux and Windows; other platforms please beware (and
223 report any bugs or strange behavior).
224
Guido van Rossum1c486092001-10-19 02:05:35 +0000225- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
226 input.
227
Tim Petersabf925f2001-09-28 21:53:42 +0000228New platforms
229
230Tests
231
232Windows
233
Tim Peters04cf1d32001-10-09 22:39:40 +0000234- Installer: If you install IDLE, and don't disable file-extension
235 registration, a new "Edit with IDLE" context (right-click) menu entry
236 is created for .py and .pyw files.
237
Tim Peters1ce3cf72001-10-01 17:58:40 +0000238- The signal module now supports SIGBREAK on Windows, thanks to Steven
239 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
240 action remains to call Win32 ExitProcess(). This can be changed via
241 signal.signal(). For example:
242
243 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
244 # (SIGINT) behavior.
245 import signal
246 signal.signal(signal.SIGBREAK,
247 signal.default_int_handler)
248
249 try:
250 while 1:
251 pass
252 except KeyboardInterrupt:
253 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
254 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
255 # program without the possibility for any Python-level cleanup).
256 print "Clean exit"
257
Tim Petersabf925f2001-09-28 21:53:42 +0000258
Tim Petersb07352e2001-09-08 01:25:47 +0000259What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000260Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000261===========================
262
Guido van Rossum808eea72001-09-25 04:15:41 +0000263Type/class unification and new-style classes
264
265- pydoc and inspect are now aware of new-style classes;
266 e.g. help(list) at the interactive prompt now shows proper
267 documentation for all operations on list objects.
268
269- Applications using Jim Fulton's ExtensionClass module can now safely
270 be used with Python 2.2. In particular, Zope 2.4.1 now works with
271 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
272 examples also work again. It is hoped that Gtk and Boost also work
273 with 2.2a4 and beyond. (If you can confirm this, please write
274 webmaster@python.org; if there are still problems, please open a bug
275 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000276
Tim Peters66c1a522001-09-24 21:17:50 +0000277- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
278 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
279 in the constructed property object. fget, fset and fdel weren't
280 discoverable from Python in 2.2a3. __doc__ is new, and allows to
281 associate a docstring with a property.
282
Guido van Rossum808eea72001-09-25 04:15:41 +0000283- Comparison overloading is now more completely implemented. For
284 example, a str subclass instance can properly be compared to a str
285 instance, and it can properly overload comparison. Ditto for most
286 other built-in object types.
287
288- The repr() of new-style classes has changed; instead of <type
289 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
290 *except* for built-in types, which are still rendered as <type
291 'Foo'> (to avoid upsetting existing code that might parse or
292 otherwise rely on repr() of certain type objects).
293
294- The repr() of new-style objects is now always <Foo object at XXX>;
295 previously, it was sometimes <Foo instance at XXX>.
296
297- For new-style classes, what was previously called __getattr__ is now
298 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000299 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000300 one in classic classes is defined which is called only if regular
301 attribute access raises AttributeError; to catch *all* attribute
302 access, you can use __getattribute__ (for new-style classes). If
303 both are defined, __getattribute__ is called first, and if it raises
304 AttributeError, __getattr__ is called.
305
306- The __class__ attribute of new-style objects can be assigned to.
307 The new class must have the same C-level object layout as the old
308 class.
309
310- The builtin file type can be subclassed now. In the usual pattern,
311 "file" is the name of the builtin type, and file() is a new builtin
312 constructor, with the same signature as the builtin open() function.
313 file() is now the preferred way to open a file.
314
315- Previously, __new__ would only see sequential arguments passed to
316 the type in a constructor call; __init__ would see both sequential
317 and keyword arguments. This made no sense whatsoever any more, so
318 now both __new__ and __init__ see all arguments.
319
320- Previously, hash() applied to an instance of a subclass of str or
321 unicode always returned 0. This has been repaired.
322
323- Previously, an operation on an instance of a subclass of an
324 immutable type (int, long, float, complex, tuple, str, unicode),
325 where the subtype didn't override the operation (and so the
326 operation was handled by the builtin type), could return that
327 instance instead a value of the base type. For example, if s was of
328 a str sublass type, s[:] returned s as-is. Now it returns a str
329 with the same value as s.
330
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000331- Provisional support for pickling new-style objects has been added.
332
Guido van Rossum808eea72001-09-25 04:15:41 +0000333Core
334
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000335- file.writelines() now accepts any iterable object producing strings.
336
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000337- PyUnicode_FromEncodedObject() now works very much like
338 PyObject_Str(obj) in that it tries to use __str__/tp_str
339 on the object if the object is not a string or buffer. This
340 makes unicode() behave like str() when applied to non-string/buffer
341 objects.
342
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000343- PyFile_WriteObject now passes Unicode objects to the file's write
344 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000345 of a print statement must support Unicode objects, i.e. they must
346 at least convert them into ASCII strings.
347
Guido van Rossum624c8af2001-09-18 15:21:04 +0000348- Thread scheduling on Solaris should be improved; it is no longer
349 necessary to insert a small sleep at the start of a thread in order
350 to let other runnable threads be scheduled.
351
Tim Petersb07352e2001-09-08 01:25:47 +0000352Library
353
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000354- StringIO.StringIO instances and cStringIO.StringIO instances support
355 read character buffer compatible objects for their .write() methods.
356 These objects are converted to strings and then handled as such
357 by the instances.
358
Barry Warsaw2f600732001-09-24 04:28:10 +0000359- The "email" package has been added. This is basically a port of the
360 mimelib package <http://sf.net/projects/mimelib> with API changes
361 and some implementations updated to use iterators and generators.
362
Tim Peters8a9c2842001-09-22 21:30:22 +0000363- difflib.ndiff() and difflib.Differ.compare() are generators now. This
364 restores the ability of Tools/scripts/ndiff.py to start producing output
365 before the entire comparison is complete.
366
Barry Warsaw58b072d2001-09-22 04:44:21 +0000367- StringIO.StringIO instances and cStringIO.StringIO instances support
368 iteration just like file objects (i.e. their .readline() method is
369 called for each iteration until it returns an empty string).
370
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000371- The codecs module has grown four new helper APIs to access
372 builtin codecs: getencoder(), getdecoder(), getreader(),
373 getwriter().
374
Guido van Rossum624c8af2001-09-18 15:21:04 +0000375- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
376 simplifies writing XML RPC servers.
377
Barry Warsaw647d5e82001-09-28 17:01:02 +0000378- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000379 after interpretation of symbolic links. On non-Unix systems, this
380 is an alias for os.path.abspath().
381
Tim Peters16a77ad2001-09-08 04:00:12 +0000382- operator.indexOf() (PySequence_Index() in the C API) now works with any
383 iterable object.
384
Guido van Rossum624c8af2001-09-18 15:21:04 +0000385- smtplib now supports various authentication and security features of
386 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000387
Guido van Rossum624c8af2001-09-18 15:21:04 +0000388- hmac: a new module implementing keyed hashing for message
389 authentication.
390
391- mimetypes now recognizes more extensions and file types. At the
392 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000393
Guido van Rossum624c8af2001-09-18 15:21:04 +0000394- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000395 Python 2.2 bytecode generation. It has also been promoted from a
396 Tool to a standard library package. (Tools/compiler still exists as
397 a sample driver.)
398
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000399Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000400
Tim Petersb07352e2001-09-08 01:25:47 +0000401Build
402
Guido van Rossum624c8af2001-09-18 15:21:04 +0000403- Large file support (LFS) is now automatic when the platform supports
404 it; no more manual configuration tweaks are needed. On Linux, at
405 least, it's possible to have a system whose C library supports large
406 files but whose kernel doesn't; in this case, large file support is
407 still enabled but doesn't do you any good unless you upgrade your
408 kernel or share your Python executable with another system whose
409 kernel has large file support.
410
411- The configure script now supplies plausible defaults in a
412 cross-compilation environment. This doesn't mean that the supplied
413 values are always correct, or that cross-compilation now works
414 flawlessly -- but it's a first step (and it shuts up most of
415 autoconf's warnings about AC_TRY_RUN).
416
417- The Unix build is now a bit less chatty, courtesy of the parser
418 generator. The build is completely silent (except for errors) when
419 using "make -s", thanks to a -q option to setup.py.
420
Tim Petersb07352e2001-09-08 01:25:47 +0000421C API
422
Guido van Rossum624c8af2001-09-18 15:21:04 +0000423- The "structmember" API now supports some new flag bits to deny read
424 and/or write access to attributes in restricted execution mode.
425
Tim Petersb07352e2001-09-08 01:25:47 +0000426New platforms
427
Guido van Rossum624c8af2001-09-18 15:21:04 +0000428- Compaq's iPAQ handheld, running the "familiar" Linux distribution
429 (http://familiar.handhelds.org).
430
Tim Petersb07352e2001-09-08 01:25:47 +0000431Tests
432
Tim Peters8a9c2842001-09-22 21:30:22 +0000433- The "classic" standard tests, which work by comparing stdout to
434 an expected-output file under Lib/test/output/, no longer stop at
435 the first mismatch. Instead the test is run to completion, and a
436 variant of ndiff-style comparison is used to report all differences.
437 This is much easier to understand than the previous style of reporting.
438
439- The unittest-based standard tests now use regrtest's test_main()
440 convention, instead of running as a side-effect of merely being
441 imported. This allows these tests to be run in more natural and
442 flexible ways as unittests, outside the regrtest framework.
443
444- regrtest.py is much better integrated with unittest and doctest now,
445 especially in regard to reporting errors.
446
Tim Petersb07352e2001-09-08 01:25:47 +0000447Windows
448
Guido van Rossum624c8af2001-09-18 15:21:04 +0000449- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000450 that support it (NTFS under Windows 2000). See "What's New in
451 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000452
Tim Petersb07352e2001-09-08 01:25:47 +0000453
Tim Petersedc99312001-08-22 21:36:50 +0000454What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000455Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000456===========================
457
458Core
459
Tim Peters9fffa3e2001-09-04 05:14:19 +0000460- Conversion of long to float now raises OverflowError if the long is too
461 big to represent as a C double.
462
Tim Peters32f453e2001-09-03 08:35:41 +0000463- The 3-argument builtin pow() no longer allows a third non-None argument
464 if either of the first two arguments is a float, or if both are of
465 integer types and the second argument is negative (in which latter case
466 the arguments are converted to float, so this is really the same
467 restriction).
468
Tim Peters5d2b77c2001-09-03 05:47:38 +0000469- The builtin dir() now returns more information, and sometimes much
470 more, generally naming all attributes of an object, and all attributes
471 reachable from the object via its class, and from its class's base
472 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
473 an empty list. In 2.2a3,
474
475 >>> dir([])
476 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
477 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
478 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
479 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
480 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
481 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
482 'reverse', 'sort']
483
484 dir(module) continues to return only the module's attributes, though.
485
Tim Petersbdee63f2001-09-02 03:40:59 +0000486- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000487 than raising OverflowError. This is a partial implementation of PEP
488 237. You can use -Wdefault::OverflowWarning to enable a warning for
489 this situation, and -Werror::OverflowWarning to revert to the old
490 OverflowError exception.
491
Guido van Rossum61c345f2001-09-04 03:26:15 +0000492- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000493 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000494 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
495 -Qold, meaning the / operator has its classic meaning and no
496 warnings are issued. Using -Qwarn issues a run-time warning about
497 all uses of classic division for int and long arguments; -Qwarnall
498 also warns about classic division for float and complex arguments
499 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
500 new division by default, but only in the __main__ module. You can
501 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
502 __main__ module new division, and warns about classic division
503 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000504
Tim Petersbdee63f2001-09-02 03:40:59 +0000505- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000506 long, float, str, unicode, and tuple. (The types complex, list and
507 dictionary can also be subclassed; this was introduced earlier.)
508 Note that restrictions apply when subclassing immutable built-in
509 types: you can only affect the value of the instance by overloading
510 __new__. You can add mutable attributes, and the subclass instances
511 will have a __dict__ attribute, but you cannot change the "value"
512 (as implemented by the base class) of an immutable subclass instance
513 once it is created.
514
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000515- The dictionary constructor now takes an optional argument, a
516 mapping-like object, and initializes the dictionary from its
517 (key, value) pairs.
518
Tim Petersbdee63f2001-09-02 03:40:59 +0000519- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000520 "cooperative super calls" in a multiple inheritance setting. For an
521 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
522
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000523- A new built-in type, property, has been added. This enables the
524 creation of "properties". These are attributes implemented by
525 getter and setter functions (or only one of these for read-only or
526 write-only attributes), without the need to override __getattr__.
527 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000528
Tim Petersbdee63f2001-09-02 03:40:59 +0000529- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000530 liberalized, to allow leading zeroes. Examples of literals now
531 legal that were SyntaxErrors before:
532
533 00.0 0e3 0100j 07.5 00000000000000000008.
534
Tim Petersbdee63f2001-09-02 03:40:59 +0000535- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000536 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
537
Tim Petersedc99312001-08-22 21:36:50 +0000538Library
539
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000540- telnetlib includes symbolic names for the options, and support for
541 setting an option negotiation callback.
542
Tim Petersa40c7932001-09-05 22:36:56 +0000543- The new C standard no longer requires that math libraries set errno to
544 ERANGE on overflow. For platform libraries that exploit this new
545 freedom, Python's overflow-checking was wholly broken. A new overflow-
546 checking scheme attempts to repair that, but may not be reliable on all
547 platforms (C doesn't seem to provide anything both useful and portable
548 in this area anymore).
549
Martin v. Löwis44f86962001-09-05 13:44:54 +0000550- Asynchronous timeout actions are available through the new class
551 threading.Timer.
552
Tim Peters78526162001-09-05 00:53:45 +0000553- math.log and math.log10 now return sensible results for even huge
554 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
555
Tim Petersbdee63f2001-09-02 03:40:59 +0000556- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000557 currently held. See the docs for the imp module.
558
Tim Petersbdee63f2001-09-02 03:40:59 +0000559- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000560 dumps containing ints written on platforms where Python ints are 8 bytes.
561 When read on a box where Python ints are 4 bytes, such values are
562 converted to Python longs.
563
Tim Petersbdee63f2001-09-02 03:40:59 +0000564- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000565 code objects is no longer allowed. This plugs a security hole.
566
Steve Purcell6091cd62001-09-06 16:05:17 +0000567- unittest.TestResult instances no longer store references to tracebacks
568 generated by test failures. This prevents unexpected dangling references
569 to objects that should be garbage collected between tests.
570
Tim Petersedc99312001-08-22 21:36:50 +0000571Tools
572
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000573- Tools/scripts/fixdiv.py has been added which can be used to fix
574 division operators as per PEP 238.
575
Tim Petersedc99312001-08-22 21:36:50 +0000576Build
577
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000578- If you are an adventurous person using Mac OS X you may want to look at
579 Mac/OSX. There is a Makefile there that will build Python as a real Mac
580 application, which can be used for experimenting with Carbon or Cocoa.
581 Discussion of this on pythonmac-sig, please.
582
Tim Peters7eea37e2001-09-04 22:08:56 +0000583C API
584
585- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000586
Tim Peters9fffa3e2001-09-04 05:14:19 +0000587- Note that PyLong_AsDouble can fail! This has always been true, but no
588 callers checked for it. It's more likely to fail now, because overflow
589 errors are properly detected now. The proper way to check:
590
591 double x = PyLong_AsDouble(some_long_object);
592 if (x == -1.0 && PyErr_Occurred()) {
593 /* The conversion failed. */
594 }
595
Tim Petersbdee63f2001-09-02 03:40:59 +0000596- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000597 compile but will not participate in GC. To upgrade an extension
598 module:
599
600 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000601
Neil Schemenauer4042c692001-08-30 15:38:01 +0000602 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
603 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000604
Neil Schemenauer4042c692001-08-30 15:38:01 +0000605 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
606 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000607
Neil Schemenauer4042c692001-08-30 15:38:01 +0000608 - remove PyGC_HEAD_SIZE from object size calculations
609
610 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
611
Tim Petersbdee63f2001-09-02 03:40:59 +0000612- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000613 These can be used safely to construct string objects from a
614 sprintf-style format string (similar to the format string supported
615 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000616
Tim Petersedc99312001-08-22 21:36:50 +0000617New platforms
618
Tim Petersb7da0902001-09-02 23:01:43 +0000619- Stephen Hansen contributed patches sufficient to get a clean compile
620 under Borland C (Windows), but he reports problems running it and ran
621 out of time to complete the port. Volunteers? Expect a MemoryError
622 when importing the types module; this is probably shallow, and
623 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000624
Tim Petersedc99312001-08-22 21:36:50 +0000625Tests
626
627Windows
628
Tim Peters6e13a562001-09-06 00:32:15 +0000629- Large file support is now enabled on Win32 platforms as well as on
630 Win64. This means that, for example, you can use f.tell() and f.seek()
631 to manipulate files larger than 2 gigabytes (provided you have enough
632 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000633 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
634 filesize limit, and large file support makes no difference there.
635 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
636 NTFS has no practical limit on file size, and files of any size can be
637 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000638
Tim Petersbdee63f2001-09-02 03:40:59 +0000639- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000640 points to command.com (patch from Brian Quinlan).
641
Tim Petersedc99312001-08-22 21:36:50 +0000642
Tim Peters20f51a72001-07-21 02:31:40 +0000643What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000644Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +0000645===========================
646
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000647Build
648
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000649- Tim Peters developed a brand new Windows installer using Wise 8.1,
650 generously donated to us by Wise Solutions.
651
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000652- configure supports a new option --enable-unicode, with the values
653 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
654 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000655
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000656- A new configure option --enable-framework builds a Mac OS X framework,
657 which "make frameworkinstall" will install. This provides a starting
658 point for more mac-like functionality, join pythonmac-sig@python.org
659 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000660
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000661- The NeXT platform is no longer supported.
662
663- The `new' module is now statically linked.
664
Tim Peters0afb6092001-08-15 06:06:44 +0000665Tools
666
667- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000668 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000669 the module docstring for details.
670
Tim Peters20f51a72001-07-21 02:31:40 +0000671Tests
672
Tim Peters5e824c32001-08-12 22:25:01 +0000673- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000674 platforms, allowing to give clearer test result output. regrtest
675 also has optional --use/-u switch to run normally disabled tests
676 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000677
Tim Peters20f51a72001-07-21 02:31:40 +0000678- Several new tests in the standard test suite, with special thanks to
679 Nick Mathewson.
680
681Core
682
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000683- The floor division operator // has been added as outlined in PEP
684 238. The / operator still provides classic division (and will until
685 Python 3.0) unless "from __future__ import division" is included, in
686 which case the / operator will provide true division. The operator
687 module provides truediv() and floordiv() functions. Augmented
688 assignment variants are included, as are the equivalent overloadable
689 methods and C API methods. See the PEP for a full discussion:
690 <http://python.sf.net/peps/pep-0238.html>
691
Tim Peters6cd6a822001-08-17 22:11:27 +0000692- Future statements are now effective in simulated interactive shells
693 (like IDLE). This should "just work" by magic, but read Michael
694 Hudson's "Future statements in simulated shells" PEP 264 for full
695 details: <http://python.sf.net/peps/pep-0264.html>.
696
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000697- The type/class unification (PEP 252-253) was integrated into the
698 trunk and is not so tentative any more (the exact specification of
699 some features is still tentative). A lot of work has done on fixing
700 bugs and adding robustness and features (performance still has to
701 come a long way).
702
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000703- Warnings about a mismatch in the Python API during extension import
704 now use the Python warning framework (which makes it possible to
705 write filters for these warnings).
706
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000707- A function's __dict__ (aka func_dict) will now always be a
708 dictionary. It used to be possible to delete it or set it to None,
709 but now both actions raise TypeErrors. It is still legal to set it
710 to a dictionary object. Getting func.__dict__ before any attributes
711 have been assigned now returns an empty dictionary instead of None.
712
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000713- A new command line option, -E, was added which disables the use of
714 all environment variables, or at least those that are specifically
715 significant to Python. Usually those have a name starting with
716 "PYTHON". This was used to fix a problem where the tests fail if
717 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
718 older distribution.
719
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000720Library
721
Tim Peters5e824c32001-08-12 22:25:01 +0000722- New class Differ and new functions ndiff() and restore() in difflib.py.
723 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000724 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000725
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000726- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
727 value using the minimal quoting required for the value; more
728 reliable than using xml.sax.saxutils.escape() for attribute values.
729
730- Readline completion support for cmd.Cmd was added.
731
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000732- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
733
734- Added function threading.BoundedSemaphore()
735
736- Added Ka-Ping Yee's cgitb.py module.
737
738- The `new' module now exposes the CO_xxx flags.
739
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000740New platforms
741
742C API
743
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000744- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
745 which provide a cross-platform implementations for the
746 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
747 the standard sprintf() and vsprintf() C lib APIs, these versions
748 apply bounds checking on the used buffer which enhances protection
749 against buffer overruns.
750
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000751- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000752 and extensions using different Unicode widths is rendered next to
753 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000754 will result in an ImportError. Unicode extensions writers must make
755 sure to check the Unicode width compatibility in their extensions by
756 using at least one of the mangled Unicode APIs in the extension.
757
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000758- Two new flags METH_NOARGS and METH_O are available in method definition
759 tables to simplify implementation of methods with no arguments and a
760 single untyped argument. Calling such methods is more efficient than
761 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
762 deprecated.
763
Tim Petersc1731372001-08-04 08:12:36 +0000764Windows
765
766- "import module" now compiles module.pyw if it exists and nothing else
767 relevant is found.
768
Tim Peters20f51a72001-07-21 02:31:40 +0000769
Guido van Rossum55a78992001-07-17 17:22:32 +0000770What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000771===========================
772
773Core
Tim Petersa814db52001-05-14 07:05:58 +0000774
Tim Peters6d6c1a32001-08-02 04:15:00 +0000775- TENTATIVELY, a large amount of code implementing much of what's
776 described in PEP 252 (Making Types Look More Like Classes) and PEP
777 253 (Subtyping Built-in Types) was added. This will be released
778 with Python 2.2a1. Documentation will be provided separately
779 through http://www.python.org/2.2/. The purpose of releasing this
780 with Python 2.2a1 is to test backwards compatibility. It is
781 possible, though not likely, that a decision is made not to release
782 this code as part of 2.2 final, if any serious backwards
783 incompapatibilities are found during alpha testing that cannot be
784 repaired.
785
Guido van Rossum55a78992001-07-17 17:22:32 +0000786- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000787 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000788 more 'yield' statements. See PEP 255. Since this adds a new
789 keyword to the language, this feature must be enabled by including a
790 future statement: "from __future__ import generators" (see PEP 236).
791 Generators will become a standard feature in a future release
792 (probably 2.3). Without this future statement, 'yield' remains an
793 ordinary identifier, but a warning is issued each time it is used.
794 (These warnings currently don't conform to the warnings framework of
795 PEP 230; we intend to fix this in 2.2a2.)
796
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000797- The UTF-16 codec was modified to be more RFC compliant. It will now
798 only remove BOM characters at the start of the string and then
799 only if running in native mode (UTF-16-LE and -BE won't remove a
800 leading BMO character).
801
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000802- Strings now have a new method .decode() to complement the already
803 existing .encode() method. These two methods provide direct access
804 to the corresponding decoders and encoders of the registered codecs.
805
806 To enhance the usability of the .encode() method, the special
807 casing of Unicode object return values was dropped (Unicode objects
808 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000809
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000810 Both methods will now return whatever the codec in charge of the
811 requested encoding returns as object, e.g. Unicode codecs will
812 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
813 will return u"äöü"). This enables codec writer to create codecs
814 for various simple to use conversions.
815
816 New codecs were added to demonstrate these new features (the .encode()
817 and .decode() columns indicate the type of the returned objects):
818
819 Name | .encode() | .decode() | Description
820 ----------------------------------------------------------------------
821 uu | string | string | UU codec (e.g. for email)
822 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000823 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000824 zlib | string | string | zlib compression
825 hex | string | string | 2-byte hex codec
826 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
827
Mark Hammond2a0af792001-05-14 03:09:36 +0000828- Some operating systems now support the concept of a default Unicode
829 encoding for file system operations. Notably, Windows supports 'mbcs'
830 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000831 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000832 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000833
834 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000835 functions that return filenames (such as os.listdir()) to return Python
836 string objects pre-encoded using the default file system encoding for
837 the platform. As this encoding is likely to be different from Python's
838 default encoding, converting this name to a Unicode object before passing
839 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000840 would attempt to use its default encoding (generally ASCII) rather than
841 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000842
Tim Petersa814db52001-05-14 07:05:58 +0000843 In general, this change simply removes surprises when working with
844 Unicode and the file system, making these operations work as you expect,
845 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000846 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000847
Tim Peters61dff2b2001-05-08 15:43:37 +0000848- Float (and complex) literals in source code were evaluated to full
849 precision only when running from a .py file; the same code loaded from a
850 .pyc (or .pyo) file could suffer numeric differences starting at about the
851 12th significant decimal digit. For example, on a machine with IEEE-754
852 floating arithmetic,
853
854 x = 9007199254740992.0
855 print long(x)
856
857 printed 9007199254740992 if run directly from .py, but 9007199254740000
858 if from a compiled (.pyc or .pyo) file. This was due to marshal using
859 str(float) instead of repr(float) when building code objects. marshal
860 now uses repr(float) instead, which should reproduce floats to full
861 machine precision (assuming the platform C float<->string I/O conversion
862 functions are of good quality).
863
864 This may cause floating-point results to change in some cases, and
865 usually for the better, but may also cause numerically unstable
866 algorithms to break.
867
Tim Peters2f228e72001-05-13 00:19:31 +0000868- The implementation of dicts suffers fewer collisions, which has speed
869 benefits. However, the order in which dict entries appear in dict.keys(),
870 dict.values() and dict.items() may differ from previous releases for a
871 given dict. Nothing is defined about this order, so no program should
872 rely on it. Nevertheless, it's easy to write test cases that rely on the
873 order by accident, typically because of printing the str() or repr() of a
874 dict to an "expected results" file. See Lib/test/test_support.py's new
875 sortdict(dict) function for a simple way to display a dict in sorted
876 order.
877
Tim Peters7a3bfc32001-06-12 01:22:22 +0000878- Many other small changes to dicts were made, resulting in faster
879 operation along the most common code paths.
880
Guido van Rossum10315822001-05-01 20:54:30 +0000881- Dictionary objects now support the "in" operator: "x in dict" means
882 the same as dict.has_key(x).
883
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000884- The update() method of dictionaries now accepts generic mapping
885 objects. Specifically the argument object must support the .keys()
886 and __getitem__() methods. This allows you to say, for example,
887 {}.update(UserDict())
888
Guido van Rossum10315822001-05-01 20:54:30 +0000889- Iterators were added; this is a generalized way of providing values
890 to a for loop. See PEP 234. There's a new built-in function iter()
891 to return an iterator. There's a new protocol to get the next value
892 from an iterator using the next() method (in Python) or the
893 tp_iternext slot (in C). There's a new protocol to get iterators
894 using the __iter__() method (in Python) or the tp_iter slot (in C).
895 Iterating (i.e. a for loop) over a dictionary generates its keys.
896 Iterating over a file generates its lines.
897
Tim Petersf553f892001-05-01 20:45:31 +0000898- The following functions were generalized to work nicely with iterator
899 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000900 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000901 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
902 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000903 join() method of strings
904 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000905 'x in y' and 'x not in y' (PySequence_Contains() in C API)
906 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000907 right-hand side of assignment statements with multiple targets, such as
908 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000909
Tim Petersd85e1022001-05-11 21:51:48 +0000910- Accessing module attributes is significantly faster (for example,
911 random.random or os.path or yourPythonModule.yourAttribute).
912
Tim Peterse63415e2001-05-08 04:38:29 +0000913- Comparing dictionary objects via == and != is faster, and now works even
914 if the keys and values don't support comparisons other than ==.
915
Tim Peters95bf9392001-05-10 08:32:44 +0000916- Comparing dictionaries in ways other than == and != is slower: there were
917 insecurities in the dict comparison implementation that could cause Python
918 to crash if the element comparison routines for the dict keys and/or
919 values mutated the dicts. Making the code bulletproof slowed it down.
920
Tim Peterseb28ef22001-06-02 05:27:19 +0000921- Collisions in dicts are resolved via a new approach, which can help
922 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000923 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000924 faster now. Thanks to Christian Tismer for pointing out the cause and
925 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000926
Tim Peters52e155e2001-06-16 05:42:57 +0000927- repr() is much faster for large containers (dict, list, tuple).
928
929
Tim Petersa814db52001-05-14 07:05:58 +0000930Library
931
Fred Drake960fdf92001-07-20 18:38:26 +0000932- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
933 were added to the string module. These a locale-indenpendent
934 constants, unlike letters, lowercase, and uppercase. These are now
935 use in appropriate locations in the standard library.
936
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000937- The flags used in dlopen calls can now be configured using
938 sys.setdlopenflags and queried using sys.getdlopenflags.
939
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000940- Fredrik Lundh's xmlrpclib is now a standard library module. This
941 provides full client-side XML-RPC support. In addition,
942 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
943 one asyncore-based). Thanks to Eric Raymond for the documentation.
944
Guido van Rossum643d3912001-07-05 14:46:25 +0000945- The xrange() object is simplified: it no longer supports slicing,
946 repetition, comparisons, efficient 'in' checking, the tolist()
947 method, or the start, stop and step attributes. See PEP 260.
948
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000949- A new function fnmatch.filter to filter lists of file names was added.
950
Barry Warsawffd674d2001-05-22 16:00:10 +0000951- calendar.py uses month and day names based on the current locale.
952
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000953- strop is now *really* obsolete (this was announced before with 1.6),
954 and issues DeprecationWarning when used (except for the four items
955 that are still imported into string.py).
956
Tim Petersa814db52001-05-14 07:05:58 +0000957- Cookie.py now sorts key+value pairs by key in output strings.
958
959- pprint.isrecursive(object) didn't correctly identify recursive objects.
960 Now it does.
961
Tim Peters95b3f782001-05-14 18:39:41 +0000962- pprint functions now much faster for large containers (tuple, list, dict).
963
Tim Peters7b9542a2001-06-10 23:40:19 +0000964- New 'q' and 'Q' format codes in the struct module, corresponding to C
965 types "long long" and "unsigned long long" (on Windows, __int64). In
966 native mode, these can be used only when the platform C compiler supports
967 these types (when HAVE_LONG_LONG is #define'd by the Python config
968 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000969 In standard mode, 'q' and 'Q' are supported on all platforms, and are
970 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000971
Guido van Rossum83213cc2001-06-12 16:48:52 +0000972- The site module installs a new built-in function 'help' that invokes
973 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
974 it displays a message reminding the user to use 'help()' or
975 'help(object)'.
976
Tim Petersa814db52001-05-14 07:05:58 +0000977Tests
978
979- New test_mutants.py runs dict comparisons where the key and value
980 comparison operators mutute the dicts randomly during comparison. This
981 rapidly causes Python to crash under earlier releases (not for the faint
982 of heart: it can also cause Win9x to freeze or reboot!).
983
984- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000985 pprint.isreadable() return sensible results. Also verifies that simple
986 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000987
Tim Peters4324aa32001-05-28 22:30:08 +0000988C API
989
990- Removed the unused last_is_sticky argument from the internal
991 _PyTuple_Resize(). If this affects you, you were cheating.
992
993
Guido van Rossum55a78992001-07-17 17:22:32 +0000994======================================================================
995
996
Guido van Rossumffe13be2001-04-16 18:46:45 +0000997What's New in Python 2.1 (final)?
998=================================
999
1000We only changed a few things since the last release candidate, all in
1001Python library code:
1002
1003- A bug in the locale module was fixed that affected locales which
1004 define no grouping for numeric formatting.
1005
1006- A few bugs in the weakref module's implementations of weak
1007 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1008 and the test suite was updated to check for these bugs.
1009
1010- An old bug in the os.path.walk() function (introduced in Python
1011 2.0!) was fixed: a non-existent file would cause an exception
1012 instead of being ignored.
1013
1014- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1015 PyChecker.
1016
1017
Guido van Rossum5b08f132001-04-16 02:05:23 +00001018What's New in Python 2.1c2?
1019===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001020
Guido van Rossum5b08f132001-04-16 02:05:23 +00001021A flurry of small changes, and one showstopper fixed in the nick of
1022time made it necessary to release another release candidate. The list
1023here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001024
Guido van Rossum5b08f132001-04-16 02:05:23 +00001025Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001026
Guido van Rossum5b08f132001-04-16 02:05:23 +00001027- Tim discovered a nasty bug in the dictionary code, caused by
1028 PyDict_Next() calling dict_resize(), and the GC code's use of
1029 PyDict_Next() violating an assumption in dict_items(). This was
1030 fixed with considerable amounts of band-aid, but the net effect is a
1031 saner and more robust implementation.
1032
1033- Made a bunch of symbols static that were accidentally global.
1034
1035Build and Ports
1036
1037- The setup.py script didn't check for a new enough version of zlib
1038 (1.1.3 is needed). Now it does.
1039
1040- Changed "make clean" target to also remove shared libraries.
1041
1042- Added a more general warning about the SGI Irix optimizer to README.
1043
1044Library
1045
1046- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1047 omitted the slash between host and file.html.
1048
1049- The mailbox module's _Mailbox class contained a completely broken
1050 and undocumented seek() method. Ripped it out.
1051
1052- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1053 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1054
1055- Fixed a few last-minute bugs in unittest.
1056
1057Extensions
1058
1059- Reverted the patch to the OpenSSL code in socketmodule.c to support
1060 RAND_status() and the EGD, and the subsequent patch that tried to
1061 fix it for pre-0.9.5 versions; the problem with the patch is that on
1062 some systems it issues a warning whenever socket is imported, and
1063 that's unacceptable.
1064
1065Tests
1066
1067- Fixed the pickle tests to work with "import test.test_pickle".
1068
1069- Tweaked test_locale.py to actually run the test Windows.
1070
1071- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1072 not "wb" (which is not a valid mode at all).
1073
1074- Fix pstats browser crashes. Import readline if it exists to make
1075 the user interface nicer.
1076
1077- Add "import thread" to the top of test modules that import the
1078 threading module (test_asynchat and test_threadedtempfile). This
1079 prevents test failures caused by a broken threading module resulting
1080 from a previously caught failed import.
1081
1082- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1083 needed on some platforms (e.g. Solaris 8) when the tests are run
1084 twice in succession.
1085
1086- Skip rather than fail test_sunaudiodev if no audio device is found.
1087
1088
1089What's New in Python 2.1c1?
1090===========================
1091
1092This list was significantly updated when 2.1c2 was released; the 2.1c1
1093release didn't mention most changes that were actually part of 2.1c1:
1094
1095Legal
1096
1097- Copyright was assigned to the Python Software Foundation (PSF) and a
1098 PSF license (very similar to the CNRI license) was added.
1099
1100- The CNRI copyright notice was updated to include 2001.
1101
1102Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001103
Guido van Rossumc9932722001-04-12 02:31:27 +00001104- After a public outcry, assignment to __debug__ is no longer illegal;
1105 instead, a warning is issued. It will become illegal in 2.2.
1106
Guido van Rossum5b08f132001-04-16 02:05:23 +00001107- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1108 "%#x" now always prepends "0x", even if the value is zero.
1109
1110- Fixed some nits in the bytecode compiler.
1111
1112- Fixed core dumps when calling certain kinds of non-functions.
1113
1114- Fixed various core dumps caused by reference count bugs.
1115
1116Build and Ports
1117
1118- Use INSTALL_SCRIPT to install script files.
1119
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001120- New port: SCO Unixware 7, by Billy G. Allie.
1121
Guido van Rossum5b08f132001-04-16 02:05:23 +00001122- Updated RISCOS port.
1123
1124- Updated BeOS port and notes.
1125
1126- Various other porting problems resolved.
1127
1128Library
1129
1130- The TERMIOS and SOCKET modules are now truly obsolete and
1131 unnecessary. Their symbols are incorporated in the termios and
1132 socket modules.
1133
1134- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1135 better tests for pickling.
1136
1137- threading: make Condition.wait() robust against KeyboardInterrupt.
1138
1139- zipfile: add support to zipfile to support opening an archive
1140 represented by an open file rather than a file name. Fix bug where
1141 the archive was not properly closed. Fixed a bug in this bugfix
1142 where flush() was called for a read-only file.
1143
1144- imputil: added an uninstall() method to the ImportManager.
1145
1146- Canvas: fixed bugs in lower() and tkraise() methods.
1147
1148- SocketServer: API change (added overridable close_request() method)
1149 so that the TCP server can explicitly close the request.
1150
1151- pstats: Eric Raymond added a simple interactive statistics browser,
1152 invoked when the module is run as a script.
1153
1154- locale: fixed a problem in format().
1155
1156- webbrowser: made it work when the BROWSER environment variable has a
1157 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1158 KDE 2. Fixed some other nits.
1159
1160- unittest: changes to allow using a different exception than
1161 AssertionError, and added a few more function aliases. Some other
1162 small changes.
1163
1164- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1165
1166- asynchat: fixed a critical bug in asynchat that slipped through the
1167 2.1b2 release. Fixed another rare bug.
1168
1169- Fix some unqualified except: clauses (always a bad code example).
1170
1171XML
1172
1173- pyexpat: new API get_version_string().
1174
1175- Fixed some minidom bugs.
1176
1177Extensions
1178
1179- Fixed a core dump in _weakref. Removed the weakref.mapping()
1180 function (it adds nothing to the API).
1181
1182- Rationalized the use of header files in the readline module, to make
1183 it compile (albeit with some warnings) with the very recent readline
1184 4.2, without breaking for earlier versions.
1185
1186- Hopefully fixed a buffering problem in linuxaudiodev.
1187
1188- Attempted a fix to make the OpenSSL support in the socket module
1189 work again with pre-0.9.5 versions of OpenSSL.
1190
1191Tests
1192
1193- Added a test case for asynchat and asyncore.
1194
1195- Removed coupling between tests where one test failing could break
1196 another.
1197
1198Tools
1199
1200- Ping added an interactive help browser to pydoc, fixed some nits
1201 in the rest of the pydoc code, and added some features to his
1202 inspect module.
1203
1204- An updated python-mode.el version 4.1 which integrates Ken
1205 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1206 much nicer in XEmacs and Emacs. When stepping through your program
1207 with pdb, in either the shell window or the *Python* window, the
1208 source file and line will be tracked by an arrow. Very cool!
1209
1210- IDLE: syntax warnings in interactive mode are changed into errors.
1211
1212- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001213 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001214
1215- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001216
Barry Warsaw11e89c72001-04-11 20:37:57 +00001217
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001218What's New in Python 2.1 beta 2?
1219================================
1220
Guido van Rossum053ae352001-03-22 14:17:21 +00001221(Unlisted are many fixed bugs, more documentation, etc.)
1222
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001223Core language, builtins, and interpreter
1224
Guido van Rossum053ae352001-03-22 14:17:21 +00001225- The nested scopes work (enabled by "from __future__ import
1226 nested_scopes") is completed; in particular, the future now extends
1227 into code executed through exec, eval() and execfile(), and into the
1228 interactive interpreter.
1229
1230- When calling a base class method (e.g. BaseClass.__init__(self)),
1231 this is now allowed even if self is not strictly spoken a class
1232 instance (e.g. when using metaclasses or the Don Beaudry hook).
1233
1234- Slice objects are now comparable but not hashable; this prevents
1235 dict[:] from being accepted but meaningless.
1236
1237- Complex division is now calculated using less braindead algorithms.
1238 This doesn't change semantics except it's more likely to give useful
1239 results in extreme cases. Complex repr() now uses full precision
1240 like float repr().
1241
1242- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1243
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001244- It is illegal to assign to the name __debug__, which is set when the
1245 interpreter starts. It is effectively a compile-time constant.
1246
1247- A warning will be issued if a global statement for a variable
1248 follows a use or assignment of that variable.
1249
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001250Standard library
1251
Guido van Rossum053ae352001-03-22 14:17:21 +00001252- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1253 inspired by JUnit), is now part of the standard library. You now
1254 have a choice of two testing frameworks: unittest requires you to
1255 write testcases as separate code, doctest gathers them from
1256 docstrings. Both approaches have their advantages and
1257 disadvantages.
1258
1259- A new module Tix was added, which wraps the Tix extension library
1260 for Tk. With that module, it is not necessary to statically link
1261 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1262 require" command. See Demo/tix/.
1263
1264- tzparse.py is now obsolete.
1265
1266- In gzip.py, the seek() and tell() methods are removed -- they were
1267 non-functional anyway, and it's better if callers can test for their
1268 existence with hasattr().
1269
1270Python/C API
1271
1272- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1273 that's already in the dictionary during a PyDict_Next() iteration.
1274 This used to fail occasionally when a dictionary resize operation
1275 could be triggered that would rehash all the keys. All other
1276 modifications to the dictionary are still off-limits during a
1277 PyDict_Next() iteration!
1278
1279- New extended APIs related to passing compiler variables around.
1280
1281- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1282 implement isinstance() and issubclass().
1283
1284- Py_BuildValue() now has a "D" conversion to create a Python complex
1285 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001286
Fred Drake4e262a92001-03-22 18:26:47 +00001287- Extensions types which support weak references must now set the
1288 field allocated for the weak reference machinery to NULL themselves;
1289 this is done to avoid the cost of checking each object for having a
1290 weakly referencable type in PyObject_INIT(), since most types are
1291 not weakly referencable.
1292
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001293- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1294 free variables and cell variables to and from the frame's f_locals.
1295
1296- Variants of several functions defined in pythonrun.h have been added
1297 to support the nested_scopes future statement. The variants all end
1298 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1299 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1300 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001301 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001302
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001303Distutils
1304
1305- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1306 into the release tree.
1307
Tim Peters0e57abf2001-05-02 07:39:38 +00001308- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001309 (an uninstaller, more customization of the installer's display)
1310
1311- from Jack Jansen: added Mac-specific code to generate a dialog for
1312 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001313 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001314 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001315
1316- added 'platforms' and 'keywords' to the set of metadata that can be
1317 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001318
1319- applied patches from Jason Tishler to make the compiler class work with
1320 Cygwin.
1321
1322
Tim Peters2fe289a2001-03-01 22:19:38 +00001323What's New in Python 2.1 beta 1?
1324================================
Tim Petersd66595f2001-02-04 03:09:53 +00001325
1326Core language, builtins, and interpreter
1327
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001328- Following an outcry from the community about the amount of code
1329 broken by the nested scopes feature introduced in 2.1a2, we decided
1330 to make this feature optional, and to wait until Python 2.2 (or at
1331 least 6 months) to make it standard. The option can be enabled on a
1332 per-module basis by adding "from __future__ import nested_scopes" at
1333 the beginning of a module (before any other statements, but after
1334 comments and an optional docstring). See PEP 236 (Back to the
1335 __future__) for a description of the __future__ statement. PEP 227
1336 (Statically Nested Scopes) has been updated to reflect this change,
1337 and to clarify the semantics in a number of endcases.
1338
1339- The nested scopes code, when enabled, has been hardened, and most
1340 bugs and memory leaks in it have been fixed.
1341
1342- Compile-time warnings are now generated for a number of conditions
1343 that will break or change in meaning when nested scopes are enabled:
1344
1345 - Using "from...import *" or "exec" without in-clause in a function
1346 scope that also defines a lambda or nested function with one or
1347 more free (non-local) variables. The presence of the import* or
1348 bare exec makes it impossible for the compiler to determine the
1349 exact set of local variables in the outer scope, which makes it
1350 impossible to determine the bindings for free variables in the
1351 inner scope. To avoid the warning about import *, change it into
1352 an import of explicitly name object, or move the import* statement
1353 to the global scope; to avoid the warning about bare exec, use
1354 exec...in... (a good idea anyway -- there's a possibility that
1355 bare exec will be deprecated in the future).
1356
1357 - Use of a global variable in a nested scope with the same name as a
1358 local variable in a surrounding scope. This will change in
1359 meaning with nested scopes: the name in the inner scope will
1360 reference the variable in the outer scope rather than the global
1361 of the same name. To avoid the warning, either rename the outer
1362 variable, or use a global statement in the inner function.
1363
Neil Schemenauera35c6882001-02-27 04:45:05 +00001364- An optional object allocator has been included. This allocator is
1365 optimized for Python objects and should be faster and use less memory
1366 than the standard system allocator. It is not enabled by default
1367 because of possible thread safety problems. The allocator is only
1368 protected by the Python interpreter lock and it is possible that some
1369 extension modules require a thread safe allocator. The object
1370 allocator can be enabled by providing the "--with-pymalloc" option to
1371 configure.
1372
Tim Petersd66595f2001-02-04 03:09:53 +00001373Standard library
1374
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001375- pyexpat now detects the expat version if expat.h defines it. A
1376 number of additional handlers are provided, which are only available
1377 since expat 1.95. In addition, the methods SetParamEntityParsing and
1378 GetInputContext of Parser objects are available with 1.95.x
1379 only. Parser objects now provide the ordered_attributes and
1380 specified_attributes attributes. A new module expat.model was added,
1381 which offers a number of additional constants if 1.95.x is used.
1382
1383- xml.dom offers the new functions registerDOMImplementation and
1384 getDOMImplementation.
1385
1386- xml.dom.minidom offers a toprettyxml method. A number of DOM
1387 conformance issues have been resolved. In particular, Element now
1388 has an hasAttributes method, and the handling of namespaces was
1389 improved.
1390
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001391- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1392 getting information about live Python code, and pydoc.py, a module
1393 for interactively converting docstrings to HTML or text.
1394 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001395 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001396 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1397 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001398
Tim Peters1eff7962001-03-01 02:31:33 +00001399- New library module difflib.py, primarily packaging the SequenceMatcher
1400 class at the heart of the popular ndiff.py file-comparison tool.
1401
1402- doctest.py (a framework for verifying Python code examples in docstrings)
1403 is now part of the std library.
1404
Tim Petersd66595f2001-02-04 03:09:53 +00001405Windows changes
1406
Guido van Rossume3955a82001-03-02 14:05:59 +00001407- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1408 small GUI that lets you browse the module docstrings using your
1409 default web browser.
1410
Tim Peters1eff7962001-03-01 02:31:33 +00001411- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1412 Platforms) is implemented. See
1413
1414 http://python.sourceforge.net/peps/pep-0235.html
1415
1416 for full details, especially the "Current Lower-Left Semantics" section.
1417 The new Windows import rules are simpler than before:
1418
1419 A. If the PYTHONCASEOK environment variable exists, same as
1420 before: silently accept the first case-insensitive match of any
1421 kind; raise ImportError if none found.
1422
1423 B. Else search sys.path for the first case-sensitive match; raise
1424 ImportError if none found.
1425
1426 The same rules have been implented on other platforms with case-
1427 insensitive but case-preserving filesystems too (including Cygwin, and
1428 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001429
Tim Peters25a9ce32001-02-19 07:06:36 +00001430- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1431 what it's supposed to do (and does do under NT and 2000) via direct
1432 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001433 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001434 all Win9x systems before.
1435
Tim Peters1eff7962001-03-01 02:31:33 +00001436- Build: Subproject _test (effectively) renamed to _testcapi.
1437
Tim Peters2fe289a2001-03-01 22:19:38 +00001438New platforms
1439
1440- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1441 Thanks to Steven Majewski!
1442
1443- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1444 Tishler!
1445
Guido van Rossum9089b272001-03-02 06:49:50 +00001446- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1447 Schwertberger! See RISCOS/README for more information -- it seems
1448 that because of the bizarre filename conventions on RISCOS, no port
1449 to that platform is easy. Note that the new variable os.endsep is
1450 silently supported in order to make life easier on this platform,
1451 but we don't advertise it because it's not worth for most folks to
1452 care about RISCOS portability.
1453
Tim Peters25a9ce32001-02-19 07:06:36 +00001454
Tim Petersd7b5e882001-01-25 03:36:26 +00001455What's New in Python 2.1 alpha 2?
1456=================================
Tim Peters40ead762001-01-27 05:35:26 +00001457
Tim Petersd7b5e882001-01-25 03:36:26 +00001458Core language, builtins, and interpreter
1459
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001460- Scopes nest. If a name is used in a function or class, but is not
1461 local, the definition in the nearest enclosing function scope will
1462 be used. One consequence of this change is that lambda statements
1463 could reference variables in the namespaces where the lambda is
1464 defined. In some unusual cases, this change will break code.
1465
1466 In all previous version of Python, names were resolved in exactly
1467 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001468 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001469 function A is defined within a function B, the names bound in B are
1470 not visible in A. The new rules make names bound in B visible in A,
1471 unless A contains a name binding that hides the binding in B.
1472
1473 Section 4.1 of the reference manual describes the new scoping rules
1474 in detail. The test script in Lib/test/test_scope.py demonstrates
1475 some of the effects of the change.
1476
1477 The new rules will cause existing code to break if it defines nested
1478 functions where an outer function has local variables with the same
1479 name as globals or builtins used by the inner function. Example:
1480
1481 def munge(str):
1482 def helper(x):
1483 return str(x)
1484 if type(str) != type(''):
1485 str = helper(str)
1486 return str.strip()
1487
1488 Under the old rules, the name str in helper() is bound to the
1489 builtin function str(). Under the new rules, it will be bound to
1490 the argument named str and an error will occur when helper() is
1491 called.
1492
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001493- The compiler will report a SyntaxError if "from ... import *" occurs
1494 in a function or class scope. The language reference has documented
1495 that this case is illegal, but the compiler never checked for it.
1496 The recent introduction of nested scope makes the meaning of this
1497 form of name binding ambiguous. In a future release, the compiler
1498 may allow this form when there is no possibility of ambiguity.
1499
Tim Peters40ead762001-01-27 05:35:26 +00001500- repr(string) is easier to read, now using hex escapes instead of octal,
1501 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1502
1503 >>> "\texample \r\n" + chr(0) + chr(255)
1504 '\texample \r\n\x00\xff' # in 2.1
1505 '\011example \015\012\000\377' # in 2.0
1506
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001507- Functions are now compared and hashed by identity, not by value, since
1508 the func_code attribute is writable.
1509
Fred Drakefb9d7122001-02-01 20:00:40 +00001510- Weak references (PEP 205) have been added. This involves a few
1511 changes in the core, an extension module (_weakref), and a Python
1512 module (weakref). The weakref module is the public interface. It
1513 includes support for "explicit" weak references, proxy objects, and
1514 mappings with weakly held values.
1515
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001516- A 'continue' statement can now appear in a try block within the body
1517 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001518 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001519
Tim Petersd7b5e882001-01-25 03:36:26 +00001520Standard library
1521
Barry Warsaw30dbd142001-01-31 22:14:01 +00001522- mailbox.py now has a new class, PortableUnixMailbox which is
1523 identical to UnixMailbox but uses a more portable scheme for
1524 determining From_ separators. Also, the constructors for all the
1525 classes in this module have a new optional `factory' argument, which
1526 is a callable used when new message classes must be instantiated by
1527 the next() method.
1528
Tim Petersd7b5e882001-01-25 03:36:26 +00001529- random.py is now self-contained, and offers all the functionality of
1530 the now-deprecated whrandom.py. See the docs for details. random.py
1531 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001532 and restoring the internal state of the generator; and jumpahead(n),
1533 for quickly forcing the internal state to be the same as if n calls to
1534 random() had been made. The latter is particularly useful for multi-
1535 threaded programs, creating one instance of the random.Random() class for
1536 each thread, then using .jumpahead() to force each instance to use a
1537 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001538
Tim Peters0de88fc2001-02-01 04:59:18 +00001539- random.py's seed() function is new. For bit-for-bit compatibility with
1540 prior releases, use the whseed function instead. The new seed function
1541 addresses two problems: (1) The old function couldn't produce more than
1542 about 2**24 distinct internal states; the new one about 2**45 (the best
1543 that can be done in the Wichmann-Hill generator). (2) The old function
1544 sometimes produced identical internal states when passed distinct
1545 integers, and there was no simple way to predict when that would happen;
1546 the new one guarantees to produce distinct internal states for all
1547 arguments in [0, 27814431486576L).
1548
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001549- The socket module now supports raw packets on Linux. The socket
1550 family is AF_PACKET.
1551
Tim Peters9ea17ac2001-02-02 05:57:15 +00001552- test_capi.py is a start at running tests of the Python C API. The tests
1553 are implemented by the new Modules/_testmodule.c.
1554
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001555- A new extension module, _symtable, provides provisional access to the
1556 internal symbol table used by the Python compiler. A higher-level
1557 interface will be added on top of _symtable in a future release.
1558
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001559- Removed the obsolete soundex module.
1560
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001561- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1562 the isSameNode method; NamedNodeMap the get method.
1563
1564- xml.sax.expatreader supports the lexical handler property; it
1565 generates comment, startCDATA, and endCDATA events.
1566
Tim Petersee826f82001-01-31 19:39:44 +00001567Windows changes
1568
1569- Build procedure: the zlib project is built in a different way that
1570 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001571 the zlib binary used. See PCbuild\readme.txt for details. Your old
1572 zlib-related directories can be deleted; you'll need to download fresh
1573 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001574
Tim Peters9ea17ac2001-02-02 05:57:15 +00001575- Build: New subproject _test for the benefit of test_capi.py (see above).
1576
Tim Petersb16c56f2001-02-02 21:24:51 +00001577- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1578 interface to some Python compiler internals).
1579
1580- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001581 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001582
Tim Petersa3a3a032000-11-30 05:22:44 +00001583What's New in Python 2.1 alpha 1?
1584=================================
1585
1586Core language, builtins, and interpreter
1587
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001588- There is a new Unicode companion to the PyObject_Str() API
1589 called PyObject_Unicode(). It behaves in the same way as the
1590 former, but assures that the returned value is an Unicode object
1591 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001592
Guido van Rossumf98eda02001-01-17 15:54:45 +00001593- The comparison operators support "rich comparison overloading" (PEP
1594 207). C extension types can provide a rich comparison function in
1595 the new tp_richcompare slot in the type object. The cmp() function
1596 and the C function PyObject_Compare() first try the new rich
1597 comparison operators before trying the old 3-way comparison. There
1598 is also a new C API PyObject_RichCompare() (which also falls back on
1599 the old 3-way comparison, but does not constrain the outcome of the
1600 rich comparison to a Boolean result).
1601
1602 The rich comparison function takes two objects (at least one of
1603 which is guaranteed to have the type that provided the function) and
1604 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1605 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1606 object, which may be NotImplemented (in which case the tp_compare
1607 slot function is used as a fallback, if defined).
1608
1609 Classes can overload individual comparison operators by defining one
1610 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001611 __ge__. There are no explicit "reflected argument" versions of
1612 these; instead, __lt__ and __gt__ are each other's reflection,
1613 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1614 reflection (similar at the C level). No other implications are
1615 made; in particular, Python does not assume that == is the Boolean
1616 inverse of !=, or that < is the Boolean inverse of >=. This makes
1617 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001618
1619 Classes or types that want to implement (in)equality tests but not
1620 the ordering operators (i.e. unordered types) should implement ==
1621 and !=, and raise an error for the ordering operators.
1622
Guido van Rossuma88479f2001-01-18 14:28:08 +00001623 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001624 Boolean; e.g. a matrix type might want to return a matrix of bits
1625 for A < B, giving elementwise comparisons. Such types should ensure
1626 that any interpretation of their value in a Boolean context raises
1627 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1628 at the C level) to always raise an exception.
1629
Guido van Rossuma88479f2001-01-18 14:28:08 +00001630- Complex numbers use rich comparisons to define == and != but raise
1631 an exception for <, <=, > and >=. Unfortunately, this also means
1632 that cmp() of two complex numbers raises an exception when the two
1633 numbers differ. Since it is not mathematically meaningful to compare
1634 complex numbers except for equality, I hope that this doesn't break
1635 too much code.
1636
Tim Peters3389f192001-02-18 08:48:49 +00001637- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001638 not defined by the language, other than that it's arbitrary but
1639 consistent (see the Reference Manual). An implementation detail changed
1640 in 2.1a1 such that None now compares less than any other object. Code
1641 relying on this new behavior (like code that relied on the previous
1642 behavior) does so at its own risk.
1643
Barry Warsaw573b5412001-01-15 20:43:18 +00001644- Functions and methods now support getting and setting arbitrarily
1645 named attributes (PEP 232). Functions have a new __dict__
1646 (a.k.a. func_dict) which hold the function attributes. Methods get
1647 and set attributes on their underlying im_func. It is a TypeError
1648 to set an attribute on a bound method.
1649
Guido van Rossum051e3352001-01-15 19:11:10 +00001650- The xrange() object implementation has been improved so that
1651 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1652 limitation that in this case len(xrange(sys.maxint)) can't be
1653 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1654 work fine as long as the index i doesn't actually reach 2**31.
1655 (Python uses regular ints for sequence and string indices; fixing
1656 that is much more work.)
1657
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001658- Two changes to from...import:
1659
Guido van Rossumba381232001-02-03 15:06:40 +00001660 1) "from M import X" now works even if (after loading module M)
1661 sys.modules['M'] is not a real module; it's basically a getattr()
1662 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001663
1664 2) "from M import *" now looks for M.__all__ to decide which names to
1665 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1666 filters out names starting with '_' as before. Whether or not
1667 __all__ exists, there's no restriction on the type of M.
1668
Guido van Rossumf61f1662001-01-10 20:13:55 +00001669- File objects have a new method, xreadlines(). This is the fastest
1670 way to iterate over all lines in a file:
1671
1672 for line in file.xreadlines():
1673 ...do something to line...
1674
1675 See the xreadlines module (mentioned below) for how to do this for
1676 other file-like objects.
1677
1678- Even if you don't use file.xreadlines(), you may expect a speedup on
1679 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001680 quite a bit in platform-specific ways: on systems (like Linux) that
1681 support flockfile(), getc_unlocked(), and funlockfile(), those are
1682 used by default. On systems (like Windows) without getc_unlocked(),
1683 a complicated (but still thread-safe) method using fgets() is used by
1684 default.
1685
Tim Petersd52269b2001-01-25 06:23:18 +00001686 You can force use of the fgets() method by #define'ing
1687 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001688 getc_unlocked()).
1689
Tim Petersd52269b2001-01-25 06:23:18 +00001690 You can force fgets() not to be used by #define'ing
1691 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001692 test_bufio.py fails -- and let us know if it does!).
1693
1694- In addition, the fileinput module, while still slower than the other
1695 methods on most platforms, has been sped up too, by using
1696 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001697
1698- Support for run-time warnings has been added, including a new
1699 command line option (-W) to specify the disposition of warnings.
1700 See the description of the warnings module below.
1701
1702- Extensive changes have been made to the coercion code. This mostly
1703 affects extension modules (which can now implement mixed-type
1704 numerical operators without having to use coercion), but
1705 occasionally, in boundary cases the coercion semantics have changed
1706 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001707 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001708 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001709 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001710
Guido van Rossumf98eda02001-01-17 15:54:45 +00001711- In connection with the coercion changes, a new built-in singleton
1712 object, NotImplemented is defined. This can be returned for
1713 operations that wish to indicate they are not implemented for a
1714 particular combination of arguments. From C, this is
1715 Py_NotImplemented.
1716
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001717- The interpreter accepts now bytecode files on the command line even
1718 if they do not have a .pyc or .pyo extension. On Linux, after executing
1719
Martin v. Löwise214baa2001-02-04 22:37:56 +00001720import imp,sys,string
1721magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1722reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1723open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001724
1725 any byte code file can be used as an executable (i.e. as an argument
1726 to execve(2)).
1727
Tim Peters9940b802000-12-01 07:59:35 +00001728- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001729 character. In 1.6 and earlier, they never produced a sign,
1730 and raised an error if the value of the long was too large
1731 to fit in a Python int. In 2.0, they produced a sign if and
1732 only if too large to fit in an int. This was inconsistent
1733 across platforms (because the size of an int varies across
1734 platforms), and inconsistent with hex() and oct(). Example:
1735
1736 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001737 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001738 'ffffffbe' # in 2.0 and before, on 32-bit machines
1739 >>> hex(-0x42L)
1740 '-0x42L' # in all versions of Python
1741
Tim Peters9940b802000-12-01 07:59:35 +00001742 The behavior of %d formats for negative Python longs remains
1743 the same as in 2.0 (although in 1.6 and before, they raised
1744 an error if the long didn't fit in a Python int).
1745
1746 %u formats don't make sense for Python longs, but are allowed
1747 and treated the same as %d in 2.1. In 2.0, a negative long
1748 formatted via %u produced a sign if and only if too large to
1749 fit in an int. In 1.6 and earlier, a negative long formatted
1750 via %u raised an error if it was too big to fit in an int.
1751
Guido van Rossum3661d392000-12-12 22:10:31 +00001752- Dictionary objects have an odd new method, popitem(). This removes
1753 an arbitrary item from the dictionary and returns it (in the form of
1754 a (key, value) pair). This can be useful for algorithms that use a
1755 dictionary as a bag of "to do" items and repeatedly need to pick one
1756 item. Such algorithms normally end up running in quadratic time;
1757 using popitem() they can usually be made to run in linear time.
1758
Tim Peters36cdad12000-12-29 02:06:45 +00001759Standard library
1760
Thomas Woutersfe385252001-01-19 23:16:56 +00001761- In the time module, the time argument to the functions strftime,
1762 localtime, gmtime, asctime and ctime is now optional, defaulting to
1763 the current time (in the local timezone).
1764
Guido van Rossumda91f222001-01-15 16:36:08 +00001765- The ftplib module now defaults to passive mode, which is deemed a
1766 more useful default given that clients are often inside firewalls
1767 these days. Note that this could break if ftplib is used to connect
1768 to a *server* that is inside a firewall, from outside; this is
1769 expected to be a very rare situation. To fix that, you can call
1770 ftp.set_pasv(0).
1771
Martin v. Löwis10a27872001-01-13 09:54:41 +00001772- The module site now treats .pth files not only for path configuration,
1773 but also supports extensions to the initialization code: Lines starting
1774 with import are executed.
1775
Guido van Rossumf61f1662001-01-10 20:13:55 +00001776- There's a new module, warnings, which implements a mechanism for
1777 issuing and filtering warnings. There are some new built-in
1778 exceptions that serve as warning categories, and a new command line
1779 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1780 turns warnings into errors). warnings.warn(message[, category])
1781 issues a warning message; this can also be called from C as
1782 PyErr_Warn(category, message).
1783
1784- A new module xreadlines was added. This exports a single factory
1785 function, xreadlines(). The intention is that this code is the
1786 absolutely fastest way to iterate over all lines in an open
1787 file(-like) object:
1788
1789 import xreadlines
1790 for line in xreadlines.xreadlines(file):
1791 ...do something to line...
1792
1793 This is equivalent to the previous the speed record holder using
1794 file.readlines(sizehint). Note that if file is a real file object
1795 (as opposed to a file-like object), this is equivalent:
1796
1797 for line in file.xreadlines():
1798 ...do something to line...
1799
Tim Peters36cdad12000-12-29 02:06:45 +00001800- The bisect module has new functions bisect_left, insort_left,
1801 bisect_right and insort_right. The old names bisect and insort
1802 are now aliases for bisect_right and insort_right. XXX_right
1803 and XXX_left methods differ in what happens when the new element
1804 compares equal to one or more elements already in the list: the
1805 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001806 right. Code that doesn't care where equal elements end up should
1807 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001808
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001809- The new curses.panel module wraps the panel library that forms part
1810 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1811
Guido van Rossumf61f1662001-01-10 20:13:55 +00001812- The SocketServer module now sets the allow_reuse_address flag by
1813 default in the TCPServer class.
1814
1815- A new function, sys._getframe(), returns the stack frame pointer of
1816 the caller. This is intended only as a building block for
1817 higher-level mechanisms such as string interpolation.
1818
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001819- The pyexpat module supports a number of new handlers, which are
1820 available only in expat 1.2. If invocation of a callback fails, it
1821 will report an additional frame in the traceback. Parser objects
1822 participate now in garbage collection. If expat reports an unknown
1823 encoding, pyexpat will try to use a Python codec; that works only
1824 for single-byte charsets. The parser type objects is exposed as
1825 XMLParserObject.
1826
1827- xml.dom now offers standard definitions for symbolic node type and
1828 exception code constants, and a hierarchy of DOM exceptions. minidom
1829 was adjusted to use them.
1830
1831- The conformance of xml.dom.minidom to the DOM specification was
1832 improved. It detects a number of additional error cases; the
1833 previous/next relationship works even when the tree is modified;
1834 Node supports the normalize() method; NamedNodeMap, DocumentType and
1835 DOMImplementation classes were added; Element supports the
1836 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1837 method.
1838
Guido van Rossumf61f1662001-01-10 20:13:55 +00001839Build issues
1840
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001841- For Unix (and Unix-compatible) builds, configuration and building of
1842 extension modules is now greatly automated. Rather than having to
1843 edit the Modules/Setup file to indicate which modules should be
1844 built and where their include files and libraries are, a
1845 distutils-based setup.py script now takes care of building most
1846 extension modules. All extension modules built this way are built
1847 as shared libraries. Only a few modules that must be linked
1848 statically are still listed in the Setup file; you won't need to
1849 edit their configuration.
1850
1851- Python should now build out of the box on Cygwin. If it doesn't,
1852 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001853
1854- Python now always uses its own (renamed) implementation of getopt()
1855 -- there's too much variation among C library getopt()
1856 implementations.
1857
1858- C++ compilers are better supported; the CXX macro is always set to a
1859 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001860
Tim Petersd92dfe02000-12-12 01:18:41 +00001861Windows changes
1862
1863- select module: By default under Windows, a select() call
1864 can specify no more than 64 sockets. Python now boosts
1865 this Microsoft default to 512. If you need even more than
1866 that, see the MS docs (you'll need to #define FD_SETSIZE
1867 and recompile Python from source).
1868
Guido van Rossumf61f1662001-01-10 20:13:55 +00001869- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1870 subdirectory is no more!
1871
Tim Petersa3a3a032000-11-30 05:22:44 +00001872
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001873What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001874=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001875
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001876Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001877changes are in the file HISTORY. If you are making the jump directly
1878from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1879HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001880
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001881Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1882the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1883http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001884
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001885--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001886
1887======================================================================
1888
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001889What's new in 2.0 (since release candidate 1)?
1890==============================================
1891
1892Standard library
1893
1894- The copy_reg module was modified to clarify its intended use: to
1895 register pickle support for extension types, not for classes.
1896 pickle() will raise a TypeError if it is passed a class.
1897
1898- Fixed a bug in gettext's "normalize and expand" code that prevented
1899 it from finding an existing .mo file.
1900
1901- Restored support for HTTP/0.9 servers in httplib.
1902
Tim Peters989b7b92000-10-16 20:24:53 +00001903- The math module was changed to stop raising OverflowError in case of
1904 underflow, and return 0 instead in underflow cases. Whether Python
1905 used to raise OverflowError in case of underflow was platform-
1906 dependent (it did when the platform math library set errno to ERANGE
1907 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001908
1909- Fixed a bug in StringIO that occurred when the file position was not
1910 at the end of the file and write() was called with enough data to
1911 extend past the end of the file.
1912
1913- Fixed a bug that caused Tkinter error messages to get lost on
1914 Windows. The bug was fixed by replacing direct use of
1915 interp->result with Tcl_GetStringResult(interp).
1916
1917- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1918 redirect response.
1919
1920- Several changes were made to distutils: Some debugging code was
1921 removed from util. Fixed the installer used when an external zip
1922 program (like WinZip) is not found; the source code for this
1923 installer is in Misc/distutils. check_lib() was modified to behave
1924 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1925 test for whether installed modules are on sys.path was changed to
1926 use both normcase() and normpath().
1927
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001928- Several minor bugs were fixed in the xml package (the minidom,
1929 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001930
1931- The regression test driver (regrtest.py) behavior when invoked with
1932 -l changed: It now reports a count of objects that are recognized as
1933 garbage but not freed by the garbage collector.
1934
Tim Peters989b7b92000-10-16 20:24:53 +00001935- The regression test for the math module was changed to test
1936 exceptional behavior when the test is run in verbose mode. Python
1937 cannot yet guarantee consistent exception behavior across platforms,
1938 so the exception part of test_math is run only in verbose mode, and
1939 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001940
1941Internals
1942
1943- PyOS_CheckStack() has been disabled on Win64, where it caused
1944 test_sre to fail.
1945
1946Build issues
1947
1948- Changed compiler flags, so that gcc is always invoked with -Wall and
1949 -Wstrict-prototypes. Users compiling Python with GCC should see
1950 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001951 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001952 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001953
Tim Petersa3a3a032000-11-30 05:22:44 +00001954- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001955
1956Tools and other miscellany
1957
1958- The compiler in Tools/compiler was updated to support the new
1959 language features introduced in 2.0: extended print statement, list
1960 comprehensions, and augmented assignments. The new compiler should
1961 also be backwards compatible with Python 1.5.2; the compiler will
1962 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001963 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001964
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001965What's new in 2.0 release candidate 1 (since beta 2)?
1966=====================================================
1967
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001968What is release candidate 1?
1969
1970We believe that release candidate 1 will fix all known bugs that we
1971intend to fix for the 2.0 final release. This release should be a bit
1972more stable than the previous betas. We would like to see even more
1973widespread testing before the final release, so we are producing this
1974release candidate. The final release will be exactly the same unless
1975any show-stopping (or brown bag) bugs are found by testers of the
1976release candidate.
1977
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001978All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001979to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001980
1981Core language, builtins, and interpreter
1982
1983- A bug that caused crashes when __coerce__ was used with augmented
1984 assignment, e.g. +=, was fixed.
1985
1986- Raise ZeroDivisionError when raising zero to a negative number,
1987 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1988 power operator and the result of math.pow(0.0, -2.0) will vary by
1989 platform. On Linux, it raises a ValueError.
1990
1991- A bug in Unicode string interpolation was fixed that occasionally
1992 caused errors with formats including "%%". For example, the
1993 following expression "%% %s" % u"abc" no longer raises a TypeError.
1994
1995- Compilation of deeply nested expressions raises MemoryError instead
1996 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1997
1998- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1999 rendering them useless. They are now written in binary mode again.
2000
2001Standard library
2002
2003- Keyword arguments are now accepted for most pattern and match object
2004 methods in SRE, the standard regular expression engine.
2005
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002006- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002007 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002008
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002009- Several bugs in the Unicode handling and error handling in _tkinter
2010 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002011
2012- Fix memory management errors in Merge() and Tkapp_Call() routines.
2013
2014- Several changes were made to cStringIO to make it compatible with
2015 the file-like object interface and with StringIO. If operations are
2016 performed on a closed object, an exception is raised. The truncate
2017 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002018 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002019
2020- There were many changes made to the linuxaudiodev module and its
2021 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002022 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002023
2024 Note that this module is named poorly, because it should work
2025 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002026 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002027
2028 The module now raises exceptions when errors occur instead of
2029 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2030 audio) and defines a getptr() method that calls the
2031 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2032
2033- The library_version attribute, introduced in an earlier beta, was
2034 removed because it can not be supported with early versions of the C
2035 readline library, which provides no way to determine the version at
2036 compile-time.
2037
2038- The binascii module is now enabled on Win64.
2039
Tim Peters46446d62000-10-09 21:19:31 +00002040- tokenize.py no longer suffers "recursion depth" errors when parsing
2041 programs with very long string literals.
2042
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002043Internals
2044
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002045- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002046 which is called when the interpreter starts up to determine where
2047 the standard library is installed. These vulnerabilities affect all
2048 previous versions of Python and can be exploited by setting very
2049 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2050 setuid Python script, although use of the wrapper in
2051 Misc/setuid-prog.c will eliminate the vulnerability.
2052
2053- Fixed garbage collection bugs in instance creation that were
2054 triggered when errors occurred during initialization. The solution,
2055 applied in cPickle and in PyInstance_New(), is to call
2056 PyObject_GC_Init() after the initialization of the object's
2057 container attributes is complete.
2058
2059- pyexpat adds definitions of PyModule_AddStringConstant and
2060 PyModule_AddObject if the Python version is less than 2.0, which
2061 provides compatibility with PyXML on Python 1.5.2.
2062
2063- If the platform has a bogus definition for LONG_BIT (the number of
2064 bits in a long), an error will be reported at compile time.
2065
2066- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2067 collection crashes and possibly other, unreported crashes.
2068
2069- Fixed a memory leak in _PyUnicode_Fini().
2070
2071Build issues
2072
2073- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002074 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002075 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002076
2077- The mmap.PAGESIZE constant is now initialized using sysconf when
2078 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2079
2080- The md5 file should now compile on all platforms.
2081
2082- The select module now compiles on platforms that do not define
2083 POLLRDNORM and related constants.
2084
2085- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002086 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002087
Jeremy Hylton10921202000-10-09 18:34:12 +00002088- BeOS: A number of changes were made to the build and installation
2089 process. ar-fake now operates on a directory of object files.
2090 dl_export.h is gone, and its macros now appear on the mwcc command
2091 line during build on PPC BeOS.
2092
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002093- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002094 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002095
2096- Cygwin: Support for shared libraries, Tkinter, and sockets.
2097
2098- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2099
2100Tools and other miscellany
2101
2102- Removed debugging prints from main used with freeze.
2103
Tim Peters46446d62000-10-09 21:19:31 +00002104- IDLE auto-indent no longer crashes when it encounters Unicode
2105 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002106
2107What's new in 2.0 beta 2 (since beta 1)?
2108========================================
2109
2110Core language, builtins, and interpreter
2111
Tim Peters482c0212000-09-26 06:33:09 +00002112- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002113 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002114
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002115- Add -h and -V command line options to print the usage message and
2116 Python version number and exit immediately.
2117
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002118- eval() and exec accept Unicode objects as code parameters.
2119
2120- getattr() and setattr() now also accept Unicode objects for the
2121 attribute name, which are converted to strings using the default
2122 encoding before lookup.
2123
2124- Multiplication on string and Unicode now does proper bounds
2125 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2126 string is too long."
2127
2128- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002129 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002130
Jeremy Hylton1b618592000-09-26 05:32:36 +00002131
2132Standard library and extensions
2133
Guido van Rossum5b08f132001-04-16 02:05:23 +00002134- socket module: the OpenSSL code now adds support for RAND_status()
2135 and EGD (Entropy Gathering Device).
2136
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002137- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002138 argument checking; it still takes no arguments.
2139
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002140- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002141
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002142- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002143
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002144- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002145
2146- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002147 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002148
2149- copy: Copy Unicode objects atomically.
2150
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002151- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002152
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002153- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002154
Fred Drake67233bc2000-09-26 16:40:27 +00002155- dbm: Add get() and setdefault() methods to dbm object. Add constant
2156 `library' to module that names the library used. Added doc strings
2157 and method names to error messages. Uses configure to determine
2158 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2159 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002160
2161- distutils: Update to version 0.9.3.
2162
2163- dl: Add several dl.RTLD_ constants.
2164
2165- fpectl: Now supported on FreeBSD.
2166
2167- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2168 found by the collector will be saved in gc.garbage. This is useful
2169 for debugging a program that creates reference cycles.
2170
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002171- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002172 of HTTP class. Do not close socket on zero-length response. Do not
2173 crash when server sends invalid content-length header.
2174
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002175- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002176
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002177- marshal: When reading a short, sign-extend on platforms where shorts
2178 are bigger than 16 bits. When reading a long, repair the unportable
2179 sign extension that was being done for 64-bit machines. (It assumed
2180 that signed right shift sign-extends.)
2181
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002182- operator: Add contains(), invert(), __invert__() as aliases for
2183 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002184
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002185- os: Add support for popen2() and popen3() on all platforms where
2186 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002187
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002188- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002189 clicking on a file in Explorer (or passing the file name to the
2190 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002191
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002192- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002193 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002194
2195- pickle: Now raises ValueError when an invalid pickle that contains
2196 a non-string repr where a string repr was expected. This behavior
2197 matches cPickle.
2198
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002199- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002200
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002201- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002202
2203- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002204 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002205 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002206
2207- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002208 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002209
2210- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002211 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002212 few cycles during startup since the first call to
2213 setdefaultencoding() will initialize the codec registry and the
2214 encodings package.
2215
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002216- socket: Support for size hint in readlines() method of object returned
2217 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002218
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002219- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002220 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002221 is followed by whitespace.
2222
Tim Petersa3a3a032000-11-30 05:22:44 +00002223- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002224
2225- struct: Check ranges for bytes and shorts.
2226
2227- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002228 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002229
2230- Tkinter: Image objects are now guaranteed to have unique ids. Set
2231 event.delta to zero if Tk version doesn't support mousewheel.
2232 Removed some debugging prints.
2233
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002234- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002235
Fred Drake67233bc2000-09-26 16:40:27 +00002236- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002237 which works around a bug in Norton AntiVirus 2000 that leads directly
2238 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002239
2240- xml: New version detection code allows PyXML to override standard
2241 XML package if PyXML version is greater than 0.6.1.
2242
Fred Drake64bb3802000-09-26 16:21:35 +00002243- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2244 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2245 tree only for nodes which are sufficiently interesting to a specific
2246 application. Does not provide the HTML-specific extensions. Still
2247 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002248
Fred Drake64bb3802000-09-26 16:21:35 +00002249- xml.sax: SAX 2 support for Python, including all the handler
2250 interfaces needed to process XML 1.0 compliant XML. Some
2251 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002252
Fred Drake64bb3802000-09-26 16:21:35 +00002253- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2254 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002255
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002256
Jeremy Hylton1b618592000-09-26 05:32:36 +00002257C API
2258
2259- Add three new convenience functions for module initialization --
2260 PyModule_AddObject(), PyModule_AddIntConstant(), and
2261 PyModule_AddStringConstant().
2262
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002263- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002264 removed and add #error to Python.h if NULL isn't defined after
2265 #include of stdio.h.
2266
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002267- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002268 backwards compatibility (at the source level) with old extensions.
2269
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002270- A wrapper API was added for signal() and sigaction(). Instead of
2271 either function, always use PyOS_getsig() to get a signal handler
2272 and PyOS_setsig() to set one. A new convenience typedef
2273 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002274
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002275- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002276 internal data buffer and size of a string object -- or the default
2277 encoded version of a Unicode object.
2278
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002279- PyString_Size() and PyString_AsString() accept Unicode objects.
2280
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002281- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002282 exists). INT_MAX and LONG_MAX will always be defined, even if
2283 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002284
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002285- PyFloat_FromString takes a second argument, pend, that was
2286 effectively useless. It is now officially useless but preserved for
2287 backwards compatibility. If the pend argument is not NULL, *pend is
2288 set to NULL.
2289
2290- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2291 for the attribute name. See note on getattr() above.
2292
2293- A few bug fixes to argument processing for Unicode.
2294 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2295 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2296 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002297 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002298
2299- Py_BuildValue accepts B format (for bgen-generated code).
2300
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002301
Jeremy Hylton1b618592000-09-26 05:32:36 +00002302Internals
2303
2304- On Unix, fix code for finding Python installation directory so that
2305 it works when argv[0] is a relative path.
2306
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002307- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002308 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002309 rather than by generating a copy of the object.
2310
Tim Peters482c0212000-09-26 06:33:09 +00002311- Several of the internal Unicode tables are much smaller now, and
2312 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002313
Jeremy Hylton97693b02000-09-26 17:42:51 +00002314- In the garbage collector: Fixed bug in collection of tuples. Fixed
2315 bug that caused some instances to be removed from the container set
2316 while they were still live. Fixed parsing in gc.set_debug() for
2317 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002318
2319- Fixed refcount problem in instance deallocation that only occurred
2320 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2321
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002322- On Windows, getpythonregpath is now protected against null data in
2323 registry key.
2324
2325- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002326 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002327
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002328
Jeremy Hylton1b618592000-09-26 05:32:36 +00002329Build and platform-specific issues
2330
2331- Better support of GNU Pth via --with-pth configure option.
2332
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002333- Python/C API now properly exposed to dynamically-loaded extension
2334 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002335
2336- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2337 Don't define MS_SYNC to be zero when it is undefined. Added missing
2338 prototypes in posixmodule.c.
2339
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002340- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002341 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002342
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002343- Fix largefile support on older NetBSD systems and OpenBSD by adding
2344 define for TELL64.
2345
2346
2347Tools and other miscellany
2348
2349- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2350
2351- freeze: The modulefinder now works with 2.0 opcodes.
2352
Tim Petersa3a3a032000-11-30 05:22:44 +00002353- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002354 Move hackery of sys.argv until after the Tk instance has been
2355 created, which allows the application-specific Tkinter
2356 initialization to be executed if present; also pass an explicit
2357 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002358
Jeremy Hylton1b618592000-09-26 05:32:36 +00002359
2360What's new in 2.0 beta 1?
2361=========================
2362
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002363Source Incompatibilities
2364------------------------
2365
2366None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2367such as single-argument append(), connect() and bind(), and changes to
2368str(long) and repr(float).
2369
2370
2371Binary Incompatibilities
2372------------------------
2373
2374- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2375with Python 2.0; these extensions will have to be rebuilt for Python
23762.0.
2377
2378- On Windows, attempting to import a third party extension built for
2379Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2380can do about this. Check your PYTHONPATH environment variable!
2381
2382- Python bytecode files (*.pyc and *.pyo) are not compatible between
2383releases.
2384
2385
2386Overview of Changes Since 1.6
2387-----------------------------
2388
2389There are many new modules (including brand new XML support through
2390the xml package, and i18n support through the gettext module); a list
2391of all new modules is included below. Lots of bugs have been fixed.
2392
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002393The process for making major new changes to the language has changed
2394since Python 1.6. Enhancements must now be documented by a Python
2395Enhancement Proposal (PEP) before they can be accepted.
2396
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002397There are several important syntax enhancements, described in more
2398detail below:
2399
2400 - Augmented assignment, e.g. x += 1
2401
2402 - List comprehensions, e.g. [x**2 for x in range(10)]
2403
2404 - Extended import statement, e.g. import Module as Name
2405
2406 - Extended print statement, e.g. print >> file, "Hello"
2407
2408Other important changes:
2409
2410 - Optional collection of cyclical garbage
2411
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002412Python Enhancement Proposal (PEP)
2413---------------------------------
2414
2415PEP stands for Python Enhancement Proposal. A PEP is a design
2416document providing information to the Python community, or describing
2417a new feature for Python. The PEP should provide a concise technical
2418specification of the feature and a rationale for the feature.
2419
2420We intend PEPs to be the primary mechanisms for proposing new
2421features, for collecting community input on an issue, and for
2422documenting the design decisions that have gone into Python. The PEP
2423author is responsible for building consensus within the community and
2424documenting dissenting opinions.
2425
2426The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002427
2428Augmented Assignment
2429--------------------
2430
2431This must have been the most-requested feature of the past years!
2432Eleven new assignment operators were added:
2433
Guido van Rossume905e952000-09-05 12:42:46 +00002434 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002435
2436For example,
2437
2438 A += B
2439
2440is similar to
2441
2442 A = A + B
2443
2444except that A is evaluated only once (relevant when A is something
2445like dict[index].attr).
2446
2447However, if A is a mutable object, A may be modified in place. Thus,
2448if A is a number or a string, A += B has the same effect as A = A+B
2449(except A is only evaluated once); but if a is a list, A += B has the
2450same effect as A.extend(B)!
2451
2452Classes and built-in object types can override the new operators in
2453order to implement the in-place behavior; the not-in-place behavior is
2454used automatically as a fallback when an object doesn't implement the
2455in-place behavior. For classes, the method name is derived from the
2456method name for the corresponding not-in-place operator by inserting
2457an 'i' in front of the name, e.g. __iadd__ implements in-place
2458__add__.
2459
2460Augmented assignment was implemented by Thomas Wouters.
2461
2462
2463List Comprehensions
2464-------------------
2465
2466This is a flexible new notation for lists whose elements are computed
2467from another list (or lists). The simplest form is:
2468
2469 [<expression> for <variable> in <sequence>]
2470
Guido van Rossum56db0952000-09-06 23:34:25 +00002471For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002472This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002473
2474You can also add a condition:
2475
2476 [<expression> for <variable> in <sequence> if <condition>]
2477
2478For example, [w for w in words if w == w.lower()] would yield the list
2479of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002480than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002481
2482You can also have nested for loops and more than one 'if' clause. For
2483example, here's a function that flattens a sequence of sequences::
2484
2485 def flatten(seq):
2486 return [x for subseq in seq for x in subseq]
2487
2488 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2489
2490This prints
2491
2492 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2493
2494List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002495Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002496
2497
2498Extended Import Statement
2499-------------------------
2500
2501Many people have asked for a way to import a module under a different
2502name. This can be accomplished like this:
2503
2504 import foo
2505 bar = foo
2506 del foo
2507
2508but this common idiom gets old quickly. A simple extension of the
2509import statement now allows this to be written as follows:
2510
2511 import foo as bar
2512
2513There's also a variant for 'from ... import':
2514
2515 from foo import bar as spam
2516
2517This also works with packages; e.g. you can write this:
2518
2519 import test.regrtest as regrtest
2520
2521Note that 'as' is not a new keyword -- it is recognized only in this
2522context (this is only possible because the syntax for the import
2523statement doesn't involve expressions).
2524
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002525Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002526
2527
2528Extended Print Statement
2529------------------------
2530
2531Easily the most controversial new feature, this extension to the print
2532statement adds an option to make the output go to a different file
2533than the default sys.stdout.
2534
2535For example, to write an error message to sys.stderr, you can now
2536write:
2537
2538 print >> sys.stderr, "Error: bad dog!"
2539
2540As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002541evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002542
2543 print >> None, "Hello world"
2544
2545is equivalent to
2546
2547 print "Hello world"
2548
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002549Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002550
2551
2552Optional Collection of Cyclical Garbage
2553---------------------------------------
2554
2555Python is now equipped with a garbage collector that can hunt down
2556cyclical references between Python objects. It's no replacement for
2557reference counting; in fact, it depends on the reference counts being
2558correct, and decides that a set of objects belong to a cycle if all
2559their reference counts can be accounted for from their references to
2560each other. This devious scheme was first proposed by Eric Tiedemann,
2561and brought to implementation by Neil Schemenauer.
2562
2563There's a module "gc" that lets you control some parameters of the
2564garbage collection. There's also an option to the configure script
2565that lets you enable or disable the garbage collection. In 2.0b1,
2566it's on by default, so that we (hopefully) can collect decent user
2567experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002568performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002569off by default in the final 2.0 release.
2570
2571
2572Smaller Changes
2573---------------
2574
2575A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2576map(None, seq1, seq2, ...) when the sequences have the same length;
2577i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2578the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002579zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002580
2581sys.version_info is a tuple (major, minor, micro, level, serial).
2582
2583Dictionaries have an odd new method, setdefault(key, default).
2584dict.setdefault(key, default) returns dict[key] if it exists; if not,
2585it sets dict[key] to default and returns that value. Thus:
2586
2587 dict.setdefault(key, []).append(item)
2588
2589does the same work as this common idiom:
2590
2591 if not dict.has_key(key):
2592 dict[key] = []
2593 dict[key].append(item)
2594
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002595There are two new variants of SyntaxError that are raised for
2596indentation-related errors: IndentationError and TabError.
2597
2598Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2599escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002600
2601The limits on the size of expressions and file in Python source code
2602have been raised from 2**16 to 2**32. Previous versions of Python
2603were limited because the maximum argument size the Python VM accepted
2604was 2**16. This limited the size of object constructor expressions,
2605e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2606limit was raised thanks to a patch by Charles Waldman that effectively
2607fixes the problem. It is now much more likely that you will be
2608limited by available memory than by an arbitrary limit in Python.
2609
2610The interpreter's maximum recursion depth can be modified by Python
2611programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2612limit is the maximum number of recursive calls that can be made by
2613Python code. The limit exists to prevent infinite recursion from
2614overflowing the C stack and causing a core dump. The default value is
26151000. The maximum safe value for a particular platform can be found
2616by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002617
2618New Modules and Packages
2619------------------------
2620
2621atexit - for registering functions to be called when Python exits.
2622
2623imputil - Greg Stein's alternative API for writing custom import
2624hooks.
2625
2626pyexpat - an interface to the Expat XML parser, contributed by Paul
2627Prescod.
2628
2629xml - a new package with XML support code organized (so far) in three
2630subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2631would fill a volume. There's a special feature whereby a
2632user-installed package named _xmlplus overrides the standard
2633xmlpackage; this is intended to give the XML SIG a hook to distribute
2634backwards-compatible updates to the standard xml package.
2635
2636webbrowser - a platform-independent API to launch a web browser.
2637
2638
Guido van Rossume905e952000-09-05 12:42:46 +00002639Changed Modules
2640---------------
2641
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002642array -- new methods for array objects: count, extend, index, pop, and
2643remove
2644
2645binascii -- new functions b2a_hex and a2b_hex that convert between
2646binary data and its hex representation
2647
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002648calendar -- Many new functions that support features including control
2649over which day of the week is the first day, returning strings instead
2650of printing them. Also new symbolic constants for days of week,
2651e.g. MONDAY, ..., SUNDAY.
2652
2653cgi -- FieldStorage objects have a getvalue method that works like a
2654dictionary's get method and returns the value attribute of the object.
2655
2656ConfigParser -- The parser object has new methods has_option,
2657remove_section, remove_option, set, and write. They allow the module
2658to be used for writing config files as well as reading them.
2659
2660ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002661optionally support the RFC 959 REST command.
2662
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002663gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002664
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002665httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2666the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002667
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002668locale -- implement getdefaultlocale for Win32 and Macintosh
2669
2670marshal -- no longer dumps core when marshaling deeply nested or
2671recursive data structures
2672
2673os -- new functions isatty, seteuid, setegid, setreuid, setregid
2674
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002675os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2676support under Unix.
2677
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002678os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002679
2680os.path -- fix semantics of os.path.commonprefix
2681
2682smtplib -- support for sending very long messages
2683
2684socket -- new function getfqdn()
2685
2686readline -- new functions to read, write and truncate history files.
2687The readline section of the library reference manual contains an
2688example.
2689
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002690select -- add interface to poll system call
2691
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002692shutil -- new copyfileobj function
2693
2694SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2695HTTP server.
2696
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002697Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002698
2699urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002700e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002701
2702whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002703
2704
2705Obsolete Modules
2706----------------
2707
2708None. However note that 1.6 made a whole slew of modules obsolete:
2709stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2710poly, zmod, strop, util, whatsound.
2711
2712
2713Changed, New, Obsolete Tools
2714----------------------------
2715
Tim Peters8b092332000-09-05 20:15:25 +00002716None.
Guido van Rossume905e952000-09-05 12:42:46 +00002717
2718
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002719C-level Changes
2720---------------
2721
2722Several cleanup jobs were carried out throughout the source code.
2723
2724All C code was converted to ANSI C; we got rid of all uses of the
2725Py_PROTO() macro, which makes the header files a lot more readable.
2726
2727Most of the portability hacks were moved to a new header file,
2728pyport.h; several other new header files were added and some old
2729header files were removed, in an attempt to create a more rational set
2730of header files. (Few of these ever need to be included explicitly;
2731they are all included by Python.h.)
2732
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002733Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002734and Win64, especially for the new Intel Itanium processor. Mick also
2735added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002736
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002737The C APIs to return an object's size have been update to consistently
2738use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2739previous versions, the abstract interfaces used PyXXX_Length and the
2740concrete interfaces used PyXXX_Size. The old names,
2741e.g. PyObject_Length, are still available for backwards compatibility
2742at the API level, but are deprecated.
2743
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002744The PyOS_CheckStack function has been implemented on Windows by
2745Fredrik Lundh. It prevents Python from failing with a stack overflow
2746on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002747
2748The GC changes resulted in creation of two new slots on object,
2749tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002750the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002751
2752The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002753C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002754
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002755PyErr_Format has been updated to automatically calculate the size of
2756the buffer needed to hold the formatted result string. This change
2757prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002758
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002759New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002760
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002761PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2762that are the same as their non-Ex counterparts except they take an
2763extra flag argument that tells them to close the file when done.
2764
2765XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002766
Tim Peters8b092332000-09-05 20:15:25 +00002767
2768Windows Changes
2769---------------
2770
2771New popen2/popen3/peopen4 in os module (see Changed Modules above).
2772
2773os.popen is much more usable on Windows 95 and 98. See Microsoft
2774Knowledge Base article Q150956. The Win9x workaround described there
2775is implemented by the new w9xpopen.exe helper in the root of your
2776Python installation. Note that Python uses this internally; it is not
2777a standalone program.
2778
2779Administrator privileges are no longer required to install Python
2780on Windows NT or Windows 2000. If you have administrator privileges,
2781Python's registry info will be written under HKEY_LOCAL_MACHINE.
2782Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002783under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002784uses of Python, but will prevent some advanced uses from working
2785(for example, running a Python script as an NT service, or possibly
2786from CGI).
2787
2788[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2789installer; instead, it installs the needed Tcl/Tk files directly in the
2790Python directory. If you already have a Tcl/Tk installation, this
2791wastes some disk space (about 4 Megs) but avoids problems with
2792conflicting Tcl/Tk installations, and makes it much easier for Python
2793to ensure that Tcl/Tk can find all its files.
2794
2795[This was new in 1.6] The Windows installer now installs by default in
2796\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2797
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002798
2799Updates to the changes between 1.5.2 and 1.6
2800--------------------------------------------
2801
2802The 1.6 NEWS file can't be changed after the release is done, so here
2803is some late-breaking news:
2804
2805New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2806and changes to getlocale() and setlocale().
2807
2808The new module is now enabled per default.
2809
2810It is not true that the encodings codecs cannot be used for normal
2811strings: the string.encode() (which is also present on 8-bit strings
2812!) allows using them for 8-bit strings too, e.g. to convert files from
2813cp1252 (Windows) to latin-1 or vice-versa.
2814
2815Japanese codecs are available from Tamito KAJIYAMA:
2816http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2817
2818
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002819======================================================================