blob: 9857d6acb77328ceac2ca344ae9bef8b69610e7d [file] [log] [blame]
Tim Petersedc99312001-08-22 21:36:50 +00001What's New in Python 2.2a3?
2===========================
3
4Core
5
Tim Petersbdee63f2001-09-02 03:40:59 +00006- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00007 than raising OverflowError. This is a partial implementation of PEP
8 237. You can use -Wdefault::OverflowWarning to enable a warning for
9 this situation, and -Werror::OverflowWarning to revert to the old
10 OverflowError exception.
11
Tim Petersbdee63f2001-09-02 03:40:59 +000012- A new command line option, -D<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +000013 warnings for the use of classic division. (See PEP 238.) Possible
14 values are -Dold, -Dwarn, and -Dnew. The default is -Dold, meaning
15 the / operator has its classic meaning and no warnings are issued.
16 Using -Dwarn issues a run-time warning about all uses of classic
17 division for int, long, float and complex arguments. Using -Dnew is
18 questionable; it turns on new division by default, but only in the
19 __main__ module. You can usefully combine -Dwarn and -Dnew: this
20 gives the __main__ module new division, and warns about classic
21 division everywhere else.
22
Tim Petersbdee63f2001-09-02 03:40:59 +000023- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +000024 long, float, str, unicode, and tuple. (The types complex, list and
25 dictionary can also be subclassed; this was introduced earlier.)
26 Note that restrictions apply when subclassing immutable built-in
27 types: you can only affect the value of the instance by overloading
28 __new__. You can add mutable attributes, and the subclass instances
29 will have a __dict__ attribute, but you cannot change the "value"
30 (as implemented by the base class) of an immutable subclass instance
31 once it is created.
32
Guido van Rossumaaf80c82001-09-02 13:44:35 +000033- The dictionary constructor now takes an optional argument, a
34 mapping-like object, and initializes the dictionary from its
35 (key, value) pairs.
36
Tim Petersbdee63f2001-09-02 03:40:59 +000037- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +000038 "cooperative super calls" in a multiple inheritance setting. For an
39 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
40
Tim Petersbdee63f2001-09-02 03:40:59 +000041- A new built-in type, getset, has been added. This enables the
Guido van Rossumae457142001-08-31 18:31:35 +000042 creation of "computed attributes". Such attributes are implemented
43 by getter and setter functions (or only one of these for read-only
44 or write-only attributes), without the need to override
45 __getattr__. See http://www.python.org/2.2/descrintro.html#getset
46
Tim Petersbdee63f2001-09-02 03:40:59 +000047- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +000048 liberalized, to allow leading zeroes. Examples of literals now
49 legal that were SyntaxErrors before:
50
51 00.0 0e3 0100j 07.5 00000000000000000008.
52
Tim Petersbdee63f2001-09-02 03:40:59 +000053- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +000054 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
55
Tim Petersedc99312001-08-22 21:36:50 +000056Library
57
Tim Petersbdee63f2001-09-02 03:40:59 +000058- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +000059 currently held. See the docs for the imp module.
60
Tim Petersbdee63f2001-09-02 03:40:59 +000061- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +000062 dumps containing ints written on platforms where Python ints are 8 bytes.
63 When read on a box where Python ints are 4 bytes, such values are
64 converted to Python longs.
65
Tim Petersbdee63f2001-09-02 03:40:59 +000066- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +000067 code objects is no longer allowed. This plugs a security hole.
68
Tim Petersedc99312001-08-22 21:36:50 +000069Tools
70
71Build
72
Tim Peters69232342001-08-30 05:16:13 +000073API
74
Tim Petersbdee63f2001-09-02 03:40:59 +000075- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +000076 compile but will not participate in GC. To upgrade an extension
77 module:
78
79 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +000080
Neil Schemenauer4042c692001-08-30 15:38:01 +000081 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
82 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +000083
Neil Schemenauer4042c692001-08-30 15:38:01 +000084 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
85 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +000086
Neil Schemenauer4042c692001-08-30 15:38:01 +000087 - remove PyGC_HEAD_SIZE from object size calculations
88
89 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
90
Tim Petersbdee63f2001-09-02 03:40:59 +000091- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +000092 These can be used safely to construct string objects from a
93 sprintf-style format string (similar to the format string supported
94 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +000095
Tim Petersedc99312001-08-22 21:36:50 +000096New platforms
97
Tim Petersbdee63f2001-09-02 03:40:59 +000098- Patches from Stephen Hansen for the Borland C compiler (under Windows)
99 are reported to yield a clean compile, but a Python that doesn't yet
100 run correctly. Volunteers?
101
Tim Petersedc99312001-08-22 21:36:50 +0000102Tests
103
104Windows
105
Tim Petersbdee63f2001-09-02 03:40:59 +0000106- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000107 points to command.com (patch from Brian Quinlan).
108
Tim Petersedc99312001-08-22 21:36:50 +0000109
Tim Peters20f51a72001-07-21 02:31:40 +0000110What's New in Python 2.2a2?
111===========================
112
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000113Build
114
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000115- Tim Peters developed a brand new Windows installer using Wise 8.1,
116 generously donated to us by Wise Solutions.
117
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000118- configure supports a new option --enable-unicode, with the values
119 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
120 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000121
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000122- A new configure option --enable-framework builds a Mac OS X framework,
123 which "make frameworkinstall" will install. This provides a starting
124 point for more mac-like functionality, join pythonmac-sig@python.org
125 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000126
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000127- The NeXT platform is no longer supported.
128
129- The `new' module is now statically linked.
130
Tim Peters0afb6092001-08-15 06:06:44 +0000131Tools
132
133- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000134 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000135 the module docstring for details.
136
Tim Peters20f51a72001-07-21 02:31:40 +0000137Tests
138
Tim Peters5e824c32001-08-12 22:25:01 +0000139- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000140 platforms, allowing to give clearer test result output. regrtest
141 also has optional --use/-u switch to run normally disabled tests
142 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000143
Tim Peters20f51a72001-07-21 02:31:40 +0000144- Several new tests in the standard test suite, with special thanks to
145 Nick Mathewson.
146
147Core
148
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000149- The floor division operator // has been added as outlined in PEP
150 238. The / operator still provides classic division (and will until
151 Python 3.0) unless "from __future__ import division" is included, in
152 which case the / operator will provide true division. The operator
153 module provides truediv() and floordiv() functions. Augmented
154 assignment variants are included, as are the equivalent overloadable
155 methods and C API methods. See the PEP for a full discussion:
156 <http://python.sf.net/peps/pep-0238.html>
157
Tim Peters6cd6a822001-08-17 22:11:27 +0000158- Future statements are now effective in simulated interactive shells
159 (like IDLE). This should "just work" by magic, but read Michael
160 Hudson's "Future statements in simulated shells" PEP 264 for full
161 details: <http://python.sf.net/peps/pep-0264.html>.
162
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000163- The type/class unification (PEP 252-253) was integrated into the
164 trunk and is not so tentative any more (the exact specification of
165 some features is still tentative). A lot of work has done on fixing
166 bugs and adding robustness and features (performance still has to
167 come a long way).
168
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000169- Warnings about a mismatch in the Python API during extension import
170 now use the Python warning framework (which makes it possible to
171 write filters for these warnings).
172
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000173- A function's __dict__ (aka func_dict) will now always be a
174 dictionary. It used to be possible to delete it or set it to None,
175 but now both actions raise TypeErrors. It is still legal to set it
176 to a dictionary object. Getting func.__dict__ before any attributes
177 have been assigned now returns an empty dictionary instead of None.
178
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000179Library
180
Tim Peters5e824c32001-08-12 22:25:01 +0000181- New class Differ and new functions ndiff() and restore() in difflib.py.
182 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000183 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000184
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000185- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
186 value using the minimal quoting required for the value; more
187 reliable than using xml.sax.saxutils.escape() for attribute values.
188
189- Readline completion support for cmd.Cmd was added.
190
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000191- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
192
193- Added function threading.BoundedSemaphore()
194
195- Added Ka-Ping Yee's cgitb.py module.
196
197- The `new' module now exposes the CO_xxx flags.
198
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000199New platforms
200
201C API
202
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000203- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
204 which provide a cross-platform implementations for the
205 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
206 the standard sprintf() and vsprintf() C lib APIs, these versions
207 apply bounds checking on the used buffer which enhances protection
208 against buffer overruns.
209
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000210- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000211 and extensions using different Unicode widths is rendered next to
212 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000213 will result in an ImportError. Unicode extensions writers must make
214 sure to check the Unicode width compatibility in their extensions by
215 using at least one of the mangled Unicode APIs in the extension.
216
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000217- Two new flags METH_NOARGS and METH_O are available in method definition
218 tables to simplify implementation of methods with no arguments and a
219 single untyped argument. Calling such methods is more efficient than
220 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
221 deprecated.
222
Tim Petersc1731372001-08-04 08:12:36 +0000223Windows
224
225- "import module" now compiles module.pyw if it exists and nothing else
226 relevant is found.
227
Tim Peters20f51a72001-07-21 02:31:40 +0000228
Guido van Rossum55a78992001-07-17 17:22:32 +0000229What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000230===========================
231
232Core
Tim Petersa814db52001-05-14 07:05:58 +0000233
Tim Peters6d6c1a32001-08-02 04:15:00 +0000234- TENTATIVELY, a large amount of code implementing much of what's
235 described in PEP 252 (Making Types Look More Like Classes) and PEP
236 253 (Subtyping Built-in Types) was added. This will be released
237 with Python 2.2a1. Documentation will be provided separately
238 through http://www.python.org/2.2/. The purpose of releasing this
239 with Python 2.2a1 is to test backwards compatibility. It is
240 possible, though not likely, that a decision is made not to release
241 this code as part of 2.2 final, if any serious backwards
242 incompapatibilities are found during alpha testing that cannot be
243 repaired.
244
Guido van Rossum55a78992001-07-17 17:22:32 +0000245- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000246 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000247 more 'yield' statements. See PEP 255. Since this adds a new
248 keyword to the language, this feature must be enabled by including a
249 future statement: "from __future__ import generators" (see PEP 236).
250 Generators will become a standard feature in a future release
251 (probably 2.3). Without this future statement, 'yield' remains an
252 ordinary identifier, but a warning is issued each time it is used.
253 (These warnings currently don't conform to the warnings framework of
254 PEP 230; we intend to fix this in 2.2a2.)
255
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000256- The UTF-16 codec was modified to be more RFC compliant. It will now
257 only remove BOM characters at the start of the string and then
258 only if running in native mode (UTF-16-LE and -BE won't remove a
259 leading BMO character).
260
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000261- Strings now have a new method .decode() to complement the already
262 existing .encode() method. These two methods provide direct access
263 to the corresponding decoders and encoders of the registered codecs.
264
265 To enhance the usability of the .encode() method, the special
266 casing of Unicode object return values was dropped (Unicode objects
267 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000268
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000269 Both methods will now return whatever the codec in charge of the
270 requested encoding returns as object, e.g. Unicode codecs will
271 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
272 will return u"äöü"). This enables codec writer to create codecs
273 for various simple to use conversions.
274
275 New codecs were added to demonstrate these new features (the .encode()
276 and .decode() columns indicate the type of the returned objects):
277
278 Name | .encode() | .decode() | Description
279 ----------------------------------------------------------------------
280 uu | string | string | UU codec (e.g. for email)
281 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000282 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000283 zlib | string | string | zlib compression
284 hex | string | string | 2-byte hex codec
285 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
286
Mark Hammond2a0af792001-05-14 03:09:36 +0000287- Some operating systems now support the concept of a default Unicode
288 encoding for file system operations. Notably, Windows supports 'mbcs'
289 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000290 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000291 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000292
293 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000294 functions that return filenames (such as os.listdir()) to return Python
295 string objects pre-encoded using the default file system encoding for
296 the platform. As this encoding is likely to be different from Python's
297 default encoding, converting this name to a Unicode object before passing
298 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000299 would attempt to use its default encoding (generally ASCII) rather than
300 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000301
Tim Petersa814db52001-05-14 07:05:58 +0000302 In general, this change simply removes surprises when working with
303 Unicode and the file system, making these operations work as you expect,
304 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000305 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000306
Tim Peters61dff2b2001-05-08 15:43:37 +0000307- Float (and complex) literals in source code were evaluated to full
308 precision only when running from a .py file; the same code loaded from a
309 .pyc (or .pyo) file could suffer numeric differences starting at about the
310 12th significant decimal digit. For example, on a machine with IEEE-754
311 floating arithmetic,
312
313 x = 9007199254740992.0
314 print long(x)
315
316 printed 9007199254740992 if run directly from .py, but 9007199254740000
317 if from a compiled (.pyc or .pyo) file. This was due to marshal using
318 str(float) instead of repr(float) when building code objects. marshal
319 now uses repr(float) instead, which should reproduce floats to full
320 machine precision (assuming the platform C float<->string I/O conversion
321 functions are of good quality).
322
323 This may cause floating-point results to change in some cases, and
324 usually for the better, but may also cause numerically unstable
325 algorithms to break.
326
Tim Peters2f228e72001-05-13 00:19:31 +0000327- The implementation of dicts suffers fewer collisions, which has speed
328 benefits. However, the order in which dict entries appear in dict.keys(),
329 dict.values() and dict.items() may differ from previous releases for a
330 given dict. Nothing is defined about this order, so no program should
331 rely on it. Nevertheless, it's easy to write test cases that rely on the
332 order by accident, typically because of printing the str() or repr() of a
333 dict to an "expected results" file. See Lib/test/test_support.py's new
334 sortdict(dict) function for a simple way to display a dict in sorted
335 order.
336
Tim Peters7a3bfc32001-06-12 01:22:22 +0000337- Many other small changes to dicts were made, resulting in faster
338 operation along the most common code paths.
339
Guido van Rossum10315822001-05-01 20:54:30 +0000340- Dictionary objects now support the "in" operator: "x in dict" means
341 the same as dict.has_key(x).
342
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000343- The update() method of dictionaries now accepts generic mapping
344 objects. Specifically the argument object must support the .keys()
345 and __getitem__() methods. This allows you to say, for example,
346 {}.update(UserDict())
347
Guido van Rossum10315822001-05-01 20:54:30 +0000348- Iterators were added; this is a generalized way of providing values
349 to a for loop. See PEP 234. There's a new built-in function iter()
350 to return an iterator. There's a new protocol to get the next value
351 from an iterator using the next() method (in Python) or the
352 tp_iternext slot (in C). There's a new protocol to get iterators
353 using the __iter__() method (in Python) or the tp_iter slot (in C).
354 Iterating (i.e. a for loop) over a dictionary generates its keys.
355 Iterating over a file generates its lines.
356
Tim Petersf553f892001-05-01 20:45:31 +0000357- The following functions were generalized to work nicely with iterator
358 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000359 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000360 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
361 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000362 join() method of strings
363 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000364 'x in y' and 'x not in y' (PySequence_Contains() in C API)
365 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000366 right-hand side of assignment statements with multiple targets, such as
367 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000368
Tim Petersd85e1022001-05-11 21:51:48 +0000369- Accessing module attributes is significantly faster (for example,
370 random.random or os.path or yourPythonModule.yourAttribute).
371
Tim Peterse63415e2001-05-08 04:38:29 +0000372- Comparing dictionary objects via == and != is faster, and now works even
373 if the keys and values don't support comparisons other than ==.
374
Tim Peters95bf9392001-05-10 08:32:44 +0000375- Comparing dictionaries in ways other than == and != is slower: there were
376 insecurities in the dict comparison implementation that could cause Python
377 to crash if the element comparison routines for the dict keys and/or
378 values mutated the dicts. Making the code bulletproof slowed it down.
379
Tim Peterseb28ef22001-06-02 05:27:19 +0000380- Collisions in dicts are resolved via a new approach, which can help
381 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000382 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000383 faster now. Thanks to Christian Tismer for pointing out the cause and
384 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000385
Tim Peters52e155e2001-06-16 05:42:57 +0000386- repr() is much faster for large containers (dict, list, tuple).
387
388
Tim Petersa814db52001-05-14 07:05:58 +0000389Library
390
Fred Drake960fdf92001-07-20 18:38:26 +0000391- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
392 were added to the string module. These a locale-indenpendent
393 constants, unlike letters, lowercase, and uppercase. These are now
394 use in appropriate locations in the standard library.
395
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000396- The flags used in dlopen calls can now be configured using
397 sys.setdlopenflags and queried using sys.getdlopenflags.
398
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000399- Fredrik Lundh's xmlrpclib is now a standard library module. This
400 provides full client-side XML-RPC support. In addition,
401 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
402 one asyncore-based). Thanks to Eric Raymond for the documentation.
403
Guido van Rossum643d3912001-07-05 14:46:25 +0000404- The xrange() object is simplified: it no longer supports slicing,
405 repetition, comparisons, efficient 'in' checking, the tolist()
406 method, or the start, stop and step attributes. See PEP 260.
407
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000408- A new function fnmatch.filter to filter lists of file names was added.
409
Barry Warsawffd674d2001-05-22 16:00:10 +0000410- calendar.py uses month and day names based on the current locale.
411
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000412- strop is now *really* obsolete (this was announced before with 1.6),
413 and issues DeprecationWarning when used (except for the four items
414 that are still imported into string.py).
415
Tim Petersa814db52001-05-14 07:05:58 +0000416- Cookie.py now sorts key+value pairs by key in output strings.
417
418- pprint.isrecursive(object) didn't correctly identify recursive objects.
419 Now it does.
420
Tim Peters95b3f782001-05-14 18:39:41 +0000421- pprint functions now much faster for large containers (tuple, list, dict).
422
Tim Peters7b9542a2001-06-10 23:40:19 +0000423- New 'q' and 'Q' format codes in the struct module, corresponding to C
424 types "long long" and "unsigned long long" (on Windows, __int64). In
425 native mode, these can be used only when the platform C compiler supports
426 these types (when HAVE_LONG_LONG is #define'd by the Python config
427 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000428 In standard mode, 'q' and 'Q' are supported on all platforms, and are
429 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000430
Guido van Rossum83213cc2001-06-12 16:48:52 +0000431- The site module installs a new built-in function 'help' that invokes
432 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
433 it displays a message reminding the user to use 'help()' or
434 'help(object)'.
435
Tim Petersa814db52001-05-14 07:05:58 +0000436Tests
437
438- New test_mutants.py runs dict comparisons where the key and value
439 comparison operators mutute the dicts randomly during comparison. This
440 rapidly causes Python to crash under earlier releases (not for the faint
441 of heart: it can also cause Win9x to freeze or reboot!).
442
443- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000444 pprint.isreadable() return sensible results. Also verifies that simple
445 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000446
Tim Peters4324aa32001-05-28 22:30:08 +0000447C API
448
449- Removed the unused last_is_sticky argument from the internal
450 _PyTuple_Resize(). If this affects you, you were cheating.
451
452
Guido van Rossum55a78992001-07-17 17:22:32 +0000453======================================================================
454
455
Guido van Rossumffe13be2001-04-16 18:46:45 +0000456What's New in Python 2.1 (final)?
457=================================
458
459We only changed a few things since the last release candidate, all in
460Python library code:
461
462- A bug in the locale module was fixed that affected locales which
463 define no grouping for numeric formatting.
464
465- A few bugs in the weakref module's implementations of weak
466 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
467 and the test suite was updated to check for these bugs.
468
469- An old bug in the os.path.walk() function (introduced in Python
470 2.0!) was fixed: a non-existent file would cause an exception
471 instead of being ignored.
472
473- Fixed a few bugs in the new symtable module found by Neil Norwitz's
474 PyChecker.
475
476
Guido van Rossum5b08f132001-04-16 02:05:23 +0000477What's New in Python 2.1c2?
478===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000479
Guido van Rossum5b08f132001-04-16 02:05:23 +0000480A flurry of small changes, and one showstopper fixed in the nick of
481time made it necessary to release another release candidate. The list
482here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000483
Guido van Rossum5b08f132001-04-16 02:05:23 +0000484Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000485
Guido van Rossum5b08f132001-04-16 02:05:23 +0000486- Tim discovered a nasty bug in the dictionary code, caused by
487 PyDict_Next() calling dict_resize(), and the GC code's use of
488 PyDict_Next() violating an assumption in dict_items(). This was
489 fixed with considerable amounts of band-aid, but the net effect is a
490 saner and more robust implementation.
491
492- Made a bunch of symbols static that were accidentally global.
493
494Build and Ports
495
496- The setup.py script didn't check for a new enough version of zlib
497 (1.1.3 is needed). Now it does.
498
499- Changed "make clean" target to also remove shared libraries.
500
501- Added a more general warning about the SGI Irix optimizer to README.
502
503Library
504
505- Fix a bug in urllib.basejoin("http://host", "../file.html") which
506 omitted the slash between host and file.html.
507
508- The mailbox module's _Mailbox class contained a completely broken
509 and undocumented seek() method. Ripped it out.
510
511- Fixed a bunch of typos in various library modules (urllib2, smtpd,
512 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
513
514- Fixed a few last-minute bugs in unittest.
515
516Extensions
517
518- Reverted the patch to the OpenSSL code in socketmodule.c to support
519 RAND_status() and the EGD, and the subsequent patch that tried to
520 fix it for pre-0.9.5 versions; the problem with the patch is that on
521 some systems it issues a warning whenever socket is imported, and
522 that's unacceptable.
523
524Tests
525
526- Fixed the pickle tests to work with "import test.test_pickle".
527
528- Tweaked test_locale.py to actually run the test Windows.
529
530- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
531 not "wb" (which is not a valid mode at all).
532
533- Fix pstats browser crashes. Import readline if it exists to make
534 the user interface nicer.
535
536- Add "import thread" to the top of test modules that import the
537 threading module (test_asynchat and test_threadedtempfile). This
538 prevents test failures caused by a broken threading module resulting
539 from a previously caught failed import.
540
541- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
542 needed on some platforms (e.g. Solaris 8) when the tests are run
543 twice in succession.
544
545- Skip rather than fail test_sunaudiodev if no audio device is found.
546
547
548What's New in Python 2.1c1?
549===========================
550
551This list was significantly updated when 2.1c2 was released; the 2.1c1
552release didn't mention most changes that were actually part of 2.1c1:
553
554Legal
555
556- Copyright was assigned to the Python Software Foundation (PSF) and a
557 PSF license (very similar to the CNRI license) was added.
558
559- The CNRI copyright notice was updated to include 2001.
560
561Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000562
Guido van Rossumc9932722001-04-12 02:31:27 +0000563- After a public outcry, assignment to __debug__ is no longer illegal;
564 instead, a warning is issued. It will become illegal in 2.2.
565
Guido van Rossum5b08f132001-04-16 02:05:23 +0000566- Fixed a core dump with "%#x" % 0, and changed the semantics so that
567 "%#x" now always prepends "0x", even if the value is zero.
568
569- Fixed some nits in the bytecode compiler.
570
571- Fixed core dumps when calling certain kinds of non-functions.
572
573- Fixed various core dumps caused by reference count bugs.
574
575Build and Ports
576
577- Use INSTALL_SCRIPT to install script files.
578
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000579- New port: SCO Unixware 7, by Billy G. Allie.
580
Guido van Rossum5b08f132001-04-16 02:05:23 +0000581- Updated RISCOS port.
582
583- Updated BeOS port and notes.
584
585- Various other porting problems resolved.
586
587Library
588
589- The TERMIOS and SOCKET modules are now truly obsolete and
590 unnecessary. Their symbols are incorporated in the termios and
591 socket modules.
592
593- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
594 better tests for pickling.
595
596- threading: make Condition.wait() robust against KeyboardInterrupt.
597
598- zipfile: add support to zipfile to support opening an archive
599 represented by an open file rather than a file name. Fix bug where
600 the archive was not properly closed. Fixed a bug in this bugfix
601 where flush() was called for a read-only file.
602
603- imputil: added an uninstall() method to the ImportManager.
604
605- Canvas: fixed bugs in lower() and tkraise() methods.
606
607- SocketServer: API change (added overridable close_request() method)
608 so that the TCP server can explicitly close the request.
609
610- pstats: Eric Raymond added a simple interactive statistics browser,
611 invoked when the module is run as a script.
612
613- locale: fixed a problem in format().
614
615- webbrowser: made it work when the BROWSER environment variable has a
616 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
617 KDE 2. Fixed some other nits.
618
619- unittest: changes to allow using a different exception than
620 AssertionError, and added a few more function aliases. Some other
621 small changes.
622
623- urllib, urllib2: fixed redirect problems and a coupleof other nits.
624
625- asynchat: fixed a critical bug in asynchat that slipped through the
626 2.1b2 release. Fixed another rare bug.
627
628- Fix some unqualified except: clauses (always a bad code example).
629
630XML
631
632- pyexpat: new API get_version_string().
633
634- Fixed some minidom bugs.
635
636Extensions
637
638- Fixed a core dump in _weakref. Removed the weakref.mapping()
639 function (it adds nothing to the API).
640
641- Rationalized the use of header files in the readline module, to make
642 it compile (albeit with some warnings) with the very recent readline
643 4.2, without breaking for earlier versions.
644
645- Hopefully fixed a buffering problem in linuxaudiodev.
646
647- Attempted a fix to make the OpenSSL support in the socket module
648 work again with pre-0.9.5 versions of OpenSSL.
649
650Tests
651
652- Added a test case for asynchat and asyncore.
653
654- Removed coupling between tests where one test failing could break
655 another.
656
657Tools
658
659- Ping added an interactive help browser to pydoc, fixed some nits
660 in the rest of the pydoc code, and added some features to his
661 inspect module.
662
663- An updated python-mode.el version 4.1 which integrates Ken
664 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
665 much nicer in XEmacs and Emacs. When stepping through your program
666 with pdb, in either the shell window or the *Python* window, the
667 source file and line will be tracked by an arrow. Very cool!
668
669- IDLE: syntax warnings in interactive mode are changed into errors.
670
671- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000672 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000673
674- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000675
Barry Warsaw11e89c72001-04-11 20:37:57 +0000676
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000677What's New in Python 2.1 beta 2?
678================================
679
Guido van Rossum053ae352001-03-22 14:17:21 +0000680(Unlisted are many fixed bugs, more documentation, etc.)
681
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000682Core language, builtins, and interpreter
683
Guido van Rossum053ae352001-03-22 14:17:21 +0000684- The nested scopes work (enabled by "from __future__ import
685 nested_scopes") is completed; in particular, the future now extends
686 into code executed through exec, eval() and execfile(), and into the
687 interactive interpreter.
688
689- When calling a base class method (e.g. BaseClass.__init__(self)),
690 this is now allowed even if self is not strictly spoken a class
691 instance (e.g. when using metaclasses or the Don Beaudry hook).
692
693- Slice objects are now comparable but not hashable; this prevents
694 dict[:] from being accepted but meaningless.
695
696- Complex division is now calculated using less braindead algorithms.
697 This doesn't change semantics except it's more likely to give useful
698 results in extreme cases. Complex repr() now uses full precision
699 like float repr().
700
701- sgmllib.py now calls handle_decl() for simple <!...> declarations.
702
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000703- It is illegal to assign to the name __debug__, which is set when the
704 interpreter starts. It is effectively a compile-time constant.
705
706- A warning will be issued if a global statement for a variable
707 follows a use or assignment of that variable.
708
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000709Standard library
710
Guido van Rossum053ae352001-03-22 14:17:21 +0000711- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
712 inspired by JUnit), is now part of the standard library. You now
713 have a choice of two testing frameworks: unittest requires you to
714 write testcases as separate code, doctest gathers them from
715 docstrings. Both approaches have their advantages and
716 disadvantages.
717
718- A new module Tix was added, which wraps the Tix extension library
719 for Tk. With that module, it is not necessary to statically link
720 Tix with _tkinter, since Tix will be loaded with Tcl's "package
721 require" command. See Demo/tix/.
722
723- tzparse.py is now obsolete.
724
725- In gzip.py, the seek() and tell() methods are removed -- they were
726 non-functional anyway, and it's better if callers can test for their
727 existence with hasattr().
728
729Python/C API
730
731- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
732 that's already in the dictionary during a PyDict_Next() iteration.
733 This used to fail occasionally when a dictionary resize operation
734 could be triggered that would rehash all the keys. All other
735 modifications to the dictionary are still off-limits during a
736 PyDict_Next() iteration!
737
738- New extended APIs related to passing compiler variables around.
739
740- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
741 implement isinstance() and issubclass().
742
743- Py_BuildValue() now has a "D" conversion to create a Python complex
744 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000745
Fred Drake4e262a92001-03-22 18:26:47 +0000746- Extensions types which support weak references must now set the
747 field allocated for the weak reference machinery to NULL themselves;
748 this is done to avoid the cost of checking each object for having a
749 weakly referencable type in PyObject_INIT(), since most types are
750 not weakly referencable.
751
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000752- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
753 free variables and cell variables to and from the frame's f_locals.
754
755- Variants of several functions defined in pythonrun.h have been added
756 to support the nested_scopes future statement. The variants all end
757 in Flags and take an extra argument, a PyCompilerFlags *; examples:
758 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
759 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000760 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000761
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000762Distutils
763
764- the sdist command now writes a PKG-INFO file, as described in PEP 241,
765 into the release tree.
766
Tim Peters0e57abf2001-05-02 07:39:38 +0000767- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000768 (an uninstaller, more customization of the installer's display)
769
770- from Jack Jansen: added Mac-specific code to generate a dialog for
771 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000772 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000773 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000774
775- added 'platforms' and 'keywords' to the set of metadata that can be
776 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000777
778- applied patches from Jason Tishler to make the compiler class work with
779 Cygwin.
780
781
Tim Peters2fe289a2001-03-01 22:19:38 +0000782What's New in Python 2.1 beta 1?
783================================
Tim Petersd66595f2001-02-04 03:09:53 +0000784
785Core language, builtins, and interpreter
786
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000787- Following an outcry from the community about the amount of code
788 broken by the nested scopes feature introduced in 2.1a2, we decided
789 to make this feature optional, and to wait until Python 2.2 (or at
790 least 6 months) to make it standard. The option can be enabled on a
791 per-module basis by adding "from __future__ import nested_scopes" at
792 the beginning of a module (before any other statements, but after
793 comments and an optional docstring). See PEP 236 (Back to the
794 __future__) for a description of the __future__ statement. PEP 227
795 (Statically Nested Scopes) has been updated to reflect this change,
796 and to clarify the semantics in a number of endcases.
797
798- The nested scopes code, when enabled, has been hardened, and most
799 bugs and memory leaks in it have been fixed.
800
801- Compile-time warnings are now generated for a number of conditions
802 that will break or change in meaning when nested scopes are enabled:
803
804 - Using "from...import *" or "exec" without in-clause in a function
805 scope that also defines a lambda or nested function with one or
806 more free (non-local) variables. The presence of the import* or
807 bare exec makes it impossible for the compiler to determine the
808 exact set of local variables in the outer scope, which makes it
809 impossible to determine the bindings for free variables in the
810 inner scope. To avoid the warning about import *, change it into
811 an import of explicitly name object, or move the import* statement
812 to the global scope; to avoid the warning about bare exec, use
813 exec...in... (a good idea anyway -- there's a possibility that
814 bare exec will be deprecated in the future).
815
816 - Use of a global variable in a nested scope with the same name as a
817 local variable in a surrounding scope. This will change in
818 meaning with nested scopes: the name in the inner scope will
819 reference the variable in the outer scope rather than the global
820 of the same name. To avoid the warning, either rename the outer
821 variable, or use a global statement in the inner function.
822
Neil Schemenauera35c6882001-02-27 04:45:05 +0000823- An optional object allocator has been included. This allocator is
824 optimized for Python objects and should be faster and use less memory
825 than the standard system allocator. It is not enabled by default
826 because of possible thread safety problems. The allocator is only
827 protected by the Python interpreter lock and it is possible that some
828 extension modules require a thread safe allocator. The object
829 allocator can be enabled by providing the "--with-pymalloc" option to
830 configure.
831
Tim Petersd66595f2001-02-04 03:09:53 +0000832Standard library
833
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000834- pyexpat now detects the expat version if expat.h defines it. A
835 number of additional handlers are provided, which are only available
836 since expat 1.95. In addition, the methods SetParamEntityParsing and
837 GetInputContext of Parser objects are available with 1.95.x
838 only. Parser objects now provide the ordered_attributes and
839 specified_attributes attributes. A new module expat.model was added,
840 which offers a number of additional constants if 1.95.x is used.
841
842- xml.dom offers the new functions registerDOMImplementation and
843 getDOMImplementation.
844
845- xml.dom.minidom offers a toprettyxml method. A number of DOM
846 conformance issues have been resolved. In particular, Element now
847 has an hasAttributes method, and the handling of namespaces was
848 improved.
849
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000850- Ka-Ping Yee contributed two new modules: inspect.py, a module for
851 getting information about live Python code, and pydoc.py, a module
852 for interactively converting docstrings to HTML or text.
853 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000854 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000855 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
856 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000857
Tim Peters1eff7962001-03-01 02:31:33 +0000858- New library module difflib.py, primarily packaging the SequenceMatcher
859 class at the heart of the popular ndiff.py file-comparison tool.
860
861- doctest.py (a framework for verifying Python code examples in docstrings)
862 is now part of the std library.
863
Tim Petersd66595f2001-02-04 03:09:53 +0000864Windows changes
865
Guido van Rossume3955a82001-03-02 14:05:59 +0000866- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
867 small GUI that lets you browse the module docstrings using your
868 default web browser.
869
Tim Peters1eff7962001-03-01 02:31:33 +0000870- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
871 Platforms) is implemented. See
872
873 http://python.sourceforge.net/peps/pep-0235.html
874
875 for full details, especially the "Current Lower-Left Semantics" section.
876 The new Windows import rules are simpler than before:
877
878 A. If the PYTHONCASEOK environment variable exists, same as
879 before: silently accept the first case-insensitive match of any
880 kind; raise ImportError if none found.
881
882 B. Else search sys.path for the first case-sensitive match; raise
883 ImportError if none found.
884
885 The same rules have been implented on other platforms with case-
886 insensitive but case-preserving filesystems too (including Cygwin, and
887 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000888
Tim Peters25a9ce32001-02-19 07:06:36 +0000889- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
890 what it's supposed to do (and does do under NT and 2000) via direct
891 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000892 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000893 all Win9x systems before.
894
Tim Peters1eff7962001-03-01 02:31:33 +0000895- Build: Subproject _test (effectively) renamed to _testcapi.
896
Tim Peters2fe289a2001-03-01 22:19:38 +0000897New platforms
898
899- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
900 Thanks to Steven Majewski!
901
902- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
903 Tishler!
904
Guido van Rossum9089b272001-03-02 06:49:50 +0000905- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
906 Schwertberger! See RISCOS/README for more information -- it seems
907 that because of the bizarre filename conventions on RISCOS, no port
908 to that platform is easy. Note that the new variable os.endsep is
909 silently supported in order to make life easier on this platform,
910 but we don't advertise it because it's not worth for most folks to
911 care about RISCOS portability.
912
Tim Peters25a9ce32001-02-19 07:06:36 +0000913
Tim Petersd7b5e882001-01-25 03:36:26 +0000914What's New in Python 2.1 alpha 2?
915=================================
Tim Peters40ead762001-01-27 05:35:26 +0000916
Tim Petersd7b5e882001-01-25 03:36:26 +0000917Core language, builtins, and interpreter
918
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000919- Scopes nest. If a name is used in a function or class, but is not
920 local, the definition in the nearest enclosing function scope will
921 be used. One consequence of this change is that lambda statements
922 could reference variables in the namespaces where the lambda is
923 defined. In some unusual cases, this change will break code.
924
925 In all previous version of Python, names were resolved in exactly
926 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000927 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000928 function A is defined within a function B, the names bound in B are
929 not visible in A. The new rules make names bound in B visible in A,
930 unless A contains a name binding that hides the binding in B.
931
932 Section 4.1 of the reference manual describes the new scoping rules
933 in detail. The test script in Lib/test/test_scope.py demonstrates
934 some of the effects of the change.
935
936 The new rules will cause existing code to break if it defines nested
937 functions where an outer function has local variables with the same
938 name as globals or builtins used by the inner function. Example:
939
940 def munge(str):
941 def helper(x):
942 return str(x)
943 if type(str) != type(''):
944 str = helper(str)
945 return str.strip()
946
947 Under the old rules, the name str in helper() is bound to the
948 builtin function str(). Under the new rules, it will be bound to
949 the argument named str and an error will occur when helper() is
950 called.
951
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000952- The compiler will report a SyntaxError if "from ... import *" occurs
953 in a function or class scope. The language reference has documented
954 that this case is illegal, but the compiler never checked for it.
955 The recent introduction of nested scope makes the meaning of this
956 form of name binding ambiguous. In a future release, the compiler
957 may allow this form when there is no possibility of ambiguity.
958
Tim Peters40ead762001-01-27 05:35:26 +0000959- repr(string) is easier to read, now using hex escapes instead of octal,
960 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
961
962 >>> "\texample \r\n" + chr(0) + chr(255)
963 '\texample \r\n\x00\xff' # in 2.1
964 '\011example \015\012\000\377' # in 2.0
965
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000966- Functions are now compared and hashed by identity, not by value, since
967 the func_code attribute is writable.
968
Fred Drakefb9d7122001-02-01 20:00:40 +0000969- Weak references (PEP 205) have been added. This involves a few
970 changes in the core, an extension module (_weakref), and a Python
971 module (weakref). The weakref module is the public interface. It
972 includes support for "explicit" weak references, proxy objects, and
973 mappings with weakly held values.
974
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000975- A 'continue' statement can now appear in a try block within the body
976 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000977 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000978
Tim Petersd7b5e882001-01-25 03:36:26 +0000979Standard library
980
Barry Warsaw30dbd142001-01-31 22:14:01 +0000981- mailbox.py now has a new class, PortableUnixMailbox which is
982 identical to UnixMailbox but uses a more portable scheme for
983 determining From_ separators. Also, the constructors for all the
984 classes in this module have a new optional `factory' argument, which
985 is a callable used when new message classes must be instantiated by
986 the next() method.
987
Tim Petersd7b5e882001-01-25 03:36:26 +0000988- random.py is now self-contained, and offers all the functionality of
989 the now-deprecated whrandom.py. See the docs for details. random.py
990 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000991 and restoring the internal state of the generator; and jumpahead(n),
992 for quickly forcing the internal state to be the same as if n calls to
993 random() had been made. The latter is particularly useful for multi-
994 threaded programs, creating one instance of the random.Random() class for
995 each thread, then using .jumpahead() to force each instance to use a
996 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000997
Tim Peters0de88fc2001-02-01 04:59:18 +0000998- random.py's seed() function is new. For bit-for-bit compatibility with
999 prior releases, use the whseed function instead. The new seed function
1000 addresses two problems: (1) The old function couldn't produce more than
1001 about 2**24 distinct internal states; the new one about 2**45 (the best
1002 that can be done in the Wichmann-Hill generator). (2) The old function
1003 sometimes produced identical internal states when passed distinct
1004 integers, and there was no simple way to predict when that would happen;
1005 the new one guarantees to produce distinct internal states for all
1006 arguments in [0, 27814431486576L).
1007
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001008- The socket module now supports raw packets on Linux. The socket
1009 family is AF_PACKET.
1010
Tim Peters9ea17ac2001-02-02 05:57:15 +00001011- test_capi.py is a start at running tests of the Python C API. The tests
1012 are implemented by the new Modules/_testmodule.c.
1013
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001014- A new extension module, _symtable, provides provisional access to the
1015 internal symbol table used by the Python compiler. A higher-level
1016 interface will be added on top of _symtable in a future release.
1017
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001018- Removed the obsolete soundex module.
1019
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001020- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1021 the isSameNode method; NamedNodeMap the get method.
1022
1023- xml.sax.expatreader supports the lexical handler property; it
1024 generates comment, startCDATA, and endCDATA events.
1025
Tim Petersee826f82001-01-31 19:39:44 +00001026Windows changes
1027
1028- Build procedure: the zlib project is built in a different way that
1029 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001030 the zlib binary used. See PCbuild\readme.txt for details. Your old
1031 zlib-related directories can be deleted; you'll need to download fresh
1032 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001033
Tim Peters9ea17ac2001-02-02 05:57:15 +00001034- Build: New subproject _test for the benefit of test_capi.py (see above).
1035
Tim Petersb16c56f2001-02-02 21:24:51 +00001036- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1037 interface to some Python compiler internals).
1038
1039- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001040 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001041
Tim Petersa3a3a032000-11-30 05:22:44 +00001042What's New in Python 2.1 alpha 1?
1043=================================
1044
1045Core language, builtins, and interpreter
1046
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001047- There is a new Unicode companion to the PyObject_Str() API
1048 called PyObject_Unicode(). It behaves in the same way as the
1049 former, but assures that the returned value is an Unicode object
1050 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001051
Guido van Rossumf98eda02001-01-17 15:54:45 +00001052- The comparison operators support "rich comparison overloading" (PEP
1053 207). C extension types can provide a rich comparison function in
1054 the new tp_richcompare slot in the type object. The cmp() function
1055 and the C function PyObject_Compare() first try the new rich
1056 comparison operators before trying the old 3-way comparison. There
1057 is also a new C API PyObject_RichCompare() (which also falls back on
1058 the old 3-way comparison, but does not constrain the outcome of the
1059 rich comparison to a Boolean result).
1060
1061 The rich comparison function takes two objects (at least one of
1062 which is guaranteed to have the type that provided the function) and
1063 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1064 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1065 object, which may be NotImplemented (in which case the tp_compare
1066 slot function is used as a fallback, if defined).
1067
1068 Classes can overload individual comparison operators by defining one
1069 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001070 __ge__. There are no explicit "reflected argument" versions of
1071 these; instead, __lt__ and __gt__ are each other's reflection,
1072 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1073 reflection (similar at the C level). No other implications are
1074 made; in particular, Python does not assume that == is the Boolean
1075 inverse of !=, or that < is the Boolean inverse of >=. This makes
1076 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001077
1078 Classes or types that want to implement (in)equality tests but not
1079 the ordering operators (i.e. unordered types) should implement ==
1080 and !=, and raise an error for the ordering operators.
1081
Guido van Rossuma88479f2001-01-18 14:28:08 +00001082 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001083 Boolean; e.g. a matrix type might want to return a matrix of bits
1084 for A < B, giving elementwise comparisons. Such types should ensure
1085 that any interpretation of their value in a Boolean context raises
1086 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1087 at the C level) to always raise an exception.
1088
Guido van Rossuma88479f2001-01-18 14:28:08 +00001089- Complex numbers use rich comparisons to define == and != but raise
1090 an exception for <, <=, > and >=. Unfortunately, this also means
1091 that cmp() of two complex numbers raises an exception when the two
1092 numbers differ. Since it is not mathematically meaningful to compare
1093 complex numbers except for equality, I hope that this doesn't break
1094 too much code.
1095
Tim Peters3389f192001-02-18 08:48:49 +00001096- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001097 not defined by the language, other than that it's arbitrary but
1098 consistent (see the Reference Manual). An implementation detail changed
1099 in 2.1a1 such that None now compares less than any other object. Code
1100 relying on this new behavior (like code that relied on the previous
1101 behavior) does so at its own risk.
1102
Barry Warsaw573b5412001-01-15 20:43:18 +00001103- Functions and methods now support getting and setting arbitrarily
1104 named attributes (PEP 232). Functions have a new __dict__
1105 (a.k.a. func_dict) which hold the function attributes. Methods get
1106 and set attributes on their underlying im_func. It is a TypeError
1107 to set an attribute on a bound method.
1108
Guido van Rossum051e3352001-01-15 19:11:10 +00001109- The xrange() object implementation has been improved so that
1110 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1111 limitation that in this case len(xrange(sys.maxint)) can't be
1112 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1113 work fine as long as the index i doesn't actually reach 2**31.
1114 (Python uses regular ints for sequence and string indices; fixing
1115 that is much more work.)
1116
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001117- Two changes to from...import:
1118
Guido van Rossumba381232001-02-03 15:06:40 +00001119 1) "from M import X" now works even if (after loading module M)
1120 sys.modules['M'] is not a real module; it's basically a getattr()
1121 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001122
1123 2) "from M import *" now looks for M.__all__ to decide which names to
1124 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1125 filters out names starting with '_' as before. Whether or not
1126 __all__ exists, there's no restriction on the type of M.
1127
Guido van Rossumf61f1662001-01-10 20:13:55 +00001128- File objects have a new method, xreadlines(). This is the fastest
1129 way to iterate over all lines in a file:
1130
1131 for line in file.xreadlines():
1132 ...do something to line...
1133
1134 See the xreadlines module (mentioned below) for how to do this for
1135 other file-like objects.
1136
1137- Even if you don't use file.xreadlines(), you may expect a speedup on
1138 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001139 quite a bit in platform-specific ways: on systems (like Linux) that
1140 support flockfile(), getc_unlocked(), and funlockfile(), those are
1141 used by default. On systems (like Windows) without getc_unlocked(),
1142 a complicated (but still thread-safe) method using fgets() is used by
1143 default.
1144
Tim Petersd52269b2001-01-25 06:23:18 +00001145 You can force use of the fgets() method by #define'ing
1146 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001147 getc_unlocked()).
1148
Tim Petersd52269b2001-01-25 06:23:18 +00001149 You can force fgets() not to be used by #define'ing
1150 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001151 test_bufio.py fails -- and let us know if it does!).
1152
1153- In addition, the fileinput module, while still slower than the other
1154 methods on most platforms, has been sped up too, by using
1155 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001156
1157- Support for run-time warnings has been added, including a new
1158 command line option (-W) to specify the disposition of warnings.
1159 See the description of the warnings module below.
1160
1161- Extensive changes have been made to the coercion code. This mostly
1162 affects extension modules (which can now implement mixed-type
1163 numerical operators without having to use coercion), but
1164 occasionally, in boundary cases the coercion semantics have changed
1165 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001166 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001167 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001168 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001169
Guido van Rossumf98eda02001-01-17 15:54:45 +00001170- In connection with the coercion changes, a new built-in singleton
1171 object, NotImplemented is defined. This can be returned for
1172 operations that wish to indicate they are not implemented for a
1173 particular combination of arguments. From C, this is
1174 Py_NotImplemented.
1175
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001176- The interpreter accepts now bytecode files on the command line even
1177 if they do not have a .pyc or .pyo extension. On Linux, after executing
1178
Martin v. Löwise214baa2001-02-04 22:37:56 +00001179import imp,sys,string
1180magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1181reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1182open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001183
1184 any byte code file can be used as an executable (i.e. as an argument
1185 to execve(2)).
1186
Tim Peters9940b802000-12-01 07:59:35 +00001187- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001188 character. In 1.6 and earlier, they never produced a sign,
1189 and raised an error if the value of the long was too large
1190 to fit in a Python int. In 2.0, they produced a sign if and
1191 only if too large to fit in an int. This was inconsistent
1192 across platforms (because the size of an int varies across
1193 platforms), and inconsistent with hex() and oct(). Example:
1194
1195 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001196 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001197 'ffffffbe' # in 2.0 and before, on 32-bit machines
1198 >>> hex(-0x42L)
1199 '-0x42L' # in all versions of Python
1200
Tim Peters9940b802000-12-01 07:59:35 +00001201 The behavior of %d formats for negative Python longs remains
1202 the same as in 2.0 (although in 1.6 and before, they raised
1203 an error if the long didn't fit in a Python int).
1204
1205 %u formats don't make sense for Python longs, but are allowed
1206 and treated the same as %d in 2.1. In 2.0, a negative long
1207 formatted via %u produced a sign if and only if too large to
1208 fit in an int. In 1.6 and earlier, a negative long formatted
1209 via %u raised an error if it was too big to fit in an int.
1210
Guido van Rossum3661d392000-12-12 22:10:31 +00001211- Dictionary objects have an odd new method, popitem(). This removes
1212 an arbitrary item from the dictionary and returns it (in the form of
1213 a (key, value) pair). This can be useful for algorithms that use a
1214 dictionary as a bag of "to do" items and repeatedly need to pick one
1215 item. Such algorithms normally end up running in quadratic time;
1216 using popitem() they can usually be made to run in linear time.
1217
Tim Peters36cdad12000-12-29 02:06:45 +00001218Standard library
1219
Thomas Woutersfe385252001-01-19 23:16:56 +00001220- In the time module, the time argument to the functions strftime,
1221 localtime, gmtime, asctime and ctime is now optional, defaulting to
1222 the current time (in the local timezone).
1223
Guido van Rossumda91f222001-01-15 16:36:08 +00001224- The ftplib module now defaults to passive mode, which is deemed a
1225 more useful default given that clients are often inside firewalls
1226 these days. Note that this could break if ftplib is used to connect
1227 to a *server* that is inside a firewall, from outside; this is
1228 expected to be a very rare situation. To fix that, you can call
1229 ftp.set_pasv(0).
1230
Martin v. Löwis10a27872001-01-13 09:54:41 +00001231- The module site now treats .pth files not only for path configuration,
1232 but also supports extensions to the initialization code: Lines starting
1233 with import are executed.
1234
Guido van Rossumf61f1662001-01-10 20:13:55 +00001235- There's a new module, warnings, which implements a mechanism for
1236 issuing and filtering warnings. There are some new built-in
1237 exceptions that serve as warning categories, and a new command line
1238 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1239 turns warnings into errors). warnings.warn(message[, category])
1240 issues a warning message; this can also be called from C as
1241 PyErr_Warn(category, message).
1242
1243- A new module xreadlines was added. This exports a single factory
1244 function, xreadlines(). The intention is that this code is the
1245 absolutely fastest way to iterate over all lines in an open
1246 file(-like) object:
1247
1248 import xreadlines
1249 for line in xreadlines.xreadlines(file):
1250 ...do something to line...
1251
1252 This is equivalent to the previous the speed record holder using
1253 file.readlines(sizehint). Note that if file is a real file object
1254 (as opposed to a file-like object), this is equivalent:
1255
1256 for line in file.xreadlines():
1257 ...do something to line...
1258
Tim Peters36cdad12000-12-29 02:06:45 +00001259- The bisect module has new functions bisect_left, insort_left,
1260 bisect_right and insort_right. The old names bisect and insort
1261 are now aliases for bisect_right and insort_right. XXX_right
1262 and XXX_left methods differ in what happens when the new element
1263 compares equal to one or more elements already in the list: the
1264 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001265 right. Code that doesn't care where equal elements end up should
1266 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001267
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001268- The new curses.panel module wraps the panel library that forms part
1269 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1270
Guido van Rossumf61f1662001-01-10 20:13:55 +00001271- The SocketServer module now sets the allow_reuse_address flag by
1272 default in the TCPServer class.
1273
1274- A new function, sys._getframe(), returns the stack frame pointer of
1275 the caller. This is intended only as a building block for
1276 higher-level mechanisms such as string interpolation.
1277
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001278- The pyexpat module supports a number of new handlers, which are
1279 available only in expat 1.2. If invocation of a callback fails, it
1280 will report an additional frame in the traceback. Parser objects
1281 participate now in garbage collection. If expat reports an unknown
1282 encoding, pyexpat will try to use a Python codec; that works only
1283 for single-byte charsets. The parser type objects is exposed as
1284 XMLParserObject.
1285
1286- xml.dom now offers standard definitions for symbolic node type and
1287 exception code constants, and a hierarchy of DOM exceptions. minidom
1288 was adjusted to use them.
1289
1290- The conformance of xml.dom.minidom to the DOM specification was
1291 improved. It detects a number of additional error cases; the
1292 previous/next relationship works even when the tree is modified;
1293 Node supports the normalize() method; NamedNodeMap, DocumentType and
1294 DOMImplementation classes were added; Element supports the
1295 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1296 method.
1297
Guido van Rossumf61f1662001-01-10 20:13:55 +00001298Build issues
1299
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001300- For Unix (and Unix-compatible) builds, configuration and building of
1301 extension modules is now greatly automated. Rather than having to
1302 edit the Modules/Setup file to indicate which modules should be
1303 built and where their include files and libraries are, a
1304 distutils-based setup.py script now takes care of building most
1305 extension modules. All extension modules built this way are built
1306 as shared libraries. Only a few modules that must be linked
1307 statically are still listed in the Setup file; you won't need to
1308 edit their configuration.
1309
1310- Python should now build out of the box on Cygwin. If it doesn't,
1311 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001312
1313- Python now always uses its own (renamed) implementation of getopt()
1314 -- there's too much variation among C library getopt()
1315 implementations.
1316
1317- C++ compilers are better supported; the CXX macro is always set to a
1318 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001319
Tim Petersd92dfe02000-12-12 01:18:41 +00001320Windows changes
1321
1322- select module: By default under Windows, a select() call
1323 can specify no more than 64 sockets. Python now boosts
1324 this Microsoft default to 512. If you need even more than
1325 that, see the MS docs (you'll need to #define FD_SETSIZE
1326 and recompile Python from source).
1327
Guido van Rossumf61f1662001-01-10 20:13:55 +00001328- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1329 subdirectory is no more!
1330
Tim Petersa3a3a032000-11-30 05:22:44 +00001331
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001332What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001333=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001334
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001335Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001336changes are in the file HISTORY. If you are making the jump directly
1337from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1338HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001339
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001340Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1341the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1342http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001343
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001344--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001345
1346======================================================================
1347
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001348What's new in 2.0 (since release candidate 1)?
1349==============================================
1350
1351Standard library
1352
1353- The copy_reg module was modified to clarify its intended use: to
1354 register pickle support for extension types, not for classes.
1355 pickle() will raise a TypeError if it is passed a class.
1356
1357- Fixed a bug in gettext's "normalize and expand" code that prevented
1358 it from finding an existing .mo file.
1359
1360- Restored support for HTTP/0.9 servers in httplib.
1361
Tim Peters989b7b92000-10-16 20:24:53 +00001362- The math module was changed to stop raising OverflowError in case of
1363 underflow, and return 0 instead in underflow cases. Whether Python
1364 used to raise OverflowError in case of underflow was platform-
1365 dependent (it did when the platform math library set errno to ERANGE
1366 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001367
1368- Fixed a bug in StringIO that occurred when the file position was not
1369 at the end of the file and write() was called with enough data to
1370 extend past the end of the file.
1371
1372- Fixed a bug that caused Tkinter error messages to get lost on
1373 Windows. The bug was fixed by replacing direct use of
1374 interp->result with Tcl_GetStringResult(interp).
1375
1376- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1377 redirect response.
1378
1379- Several changes were made to distutils: Some debugging code was
1380 removed from util. Fixed the installer used when an external zip
1381 program (like WinZip) is not found; the source code for this
1382 installer is in Misc/distutils. check_lib() was modified to behave
1383 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1384 test for whether installed modules are on sys.path was changed to
1385 use both normcase() and normpath().
1386
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001387- Several minor bugs were fixed in the xml package (the minidom,
1388 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001389
1390- The regression test driver (regrtest.py) behavior when invoked with
1391 -l changed: It now reports a count of objects that are recognized as
1392 garbage but not freed by the garbage collector.
1393
Tim Peters989b7b92000-10-16 20:24:53 +00001394- The regression test for the math module was changed to test
1395 exceptional behavior when the test is run in verbose mode. Python
1396 cannot yet guarantee consistent exception behavior across platforms,
1397 so the exception part of test_math is run only in verbose mode, and
1398 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001399
1400Internals
1401
1402- PyOS_CheckStack() has been disabled on Win64, where it caused
1403 test_sre to fail.
1404
1405Build issues
1406
1407- Changed compiler flags, so that gcc is always invoked with -Wall and
1408 -Wstrict-prototypes. Users compiling Python with GCC should see
1409 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001410 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001411 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001412
Tim Petersa3a3a032000-11-30 05:22:44 +00001413- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001414
1415Tools and other miscellany
1416
1417- The compiler in Tools/compiler was updated to support the new
1418 language features introduced in 2.0: extended print statement, list
1419 comprehensions, and augmented assignments. The new compiler should
1420 also be backwards compatible with Python 1.5.2; the compiler will
1421 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001422 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001423
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001424What's new in 2.0 release candidate 1 (since beta 2)?
1425=====================================================
1426
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001427What is release candidate 1?
1428
1429We believe that release candidate 1 will fix all known bugs that we
1430intend to fix for the 2.0 final release. This release should be a bit
1431more stable than the previous betas. We would like to see even more
1432widespread testing before the final release, so we are producing this
1433release candidate. The final release will be exactly the same unless
1434any show-stopping (or brown bag) bugs are found by testers of the
1435release candidate.
1436
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001437All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001438to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001439
1440Core language, builtins, and interpreter
1441
1442- A bug that caused crashes when __coerce__ was used with augmented
1443 assignment, e.g. +=, was fixed.
1444
1445- Raise ZeroDivisionError when raising zero to a negative number,
1446 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1447 power operator and the result of math.pow(0.0, -2.0) will vary by
1448 platform. On Linux, it raises a ValueError.
1449
1450- A bug in Unicode string interpolation was fixed that occasionally
1451 caused errors with formats including "%%". For example, the
1452 following expression "%% %s" % u"abc" no longer raises a TypeError.
1453
1454- Compilation of deeply nested expressions raises MemoryError instead
1455 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1456
1457- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1458 rendering them useless. They are now written in binary mode again.
1459
1460Standard library
1461
1462- Keyword arguments are now accepted for most pattern and match object
1463 methods in SRE, the standard regular expression engine.
1464
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001465- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001466 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001467
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001468- Several bugs in the Unicode handling and error handling in _tkinter
1469 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001470
1471- Fix memory management errors in Merge() and Tkapp_Call() routines.
1472
1473- Several changes were made to cStringIO to make it compatible with
1474 the file-like object interface and with StringIO. If operations are
1475 performed on a closed object, an exception is raised. The truncate
1476 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001477 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001478
1479- There were many changes made to the linuxaudiodev module and its
1480 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001481 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001482
1483 Note that this module is named poorly, because it should work
1484 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001485 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001486
1487 The module now raises exceptions when errors occur instead of
1488 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1489 audio) and defines a getptr() method that calls the
1490 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1491
1492- The library_version attribute, introduced in an earlier beta, was
1493 removed because it can not be supported with early versions of the C
1494 readline library, which provides no way to determine the version at
1495 compile-time.
1496
1497- The binascii module is now enabled on Win64.
1498
Tim Peters46446d62000-10-09 21:19:31 +00001499- tokenize.py no longer suffers "recursion depth" errors when parsing
1500 programs with very long string literals.
1501
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001502Internals
1503
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001504- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001505 which is called when the interpreter starts up to determine where
1506 the standard library is installed. These vulnerabilities affect all
1507 previous versions of Python and can be exploited by setting very
1508 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1509 setuid Python script, although use of the wrapper in
1510 Misc/setuid-prog.c will eliminate the vulnerability.
1511
1512- Fixed garbage collection bugs in instance creation that were
1513 triggered when errors occurred during initialization. The solution,
1514 applied in cPickle and in PyInstance_New(), is to call
1515 PyObject_GC_Init() after the initialization of the object's
1516 container attributes is complete.
1517
1518- pyexpat adds definitions of PyModule_AddStringConstant and
1519 PyModule_AddObject if the Python version is less than 2.0, which
1520 provides compatibility with PyXML on Python 1.5.2.
1521
1522- If the platform has a bogus definition for LONG_BIT (the number of
1523 bits in a long), an error will be reported at compile time.
1524
1525- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1526 collection crashes and possibly other, unreported crashes.
1527
1528- Fixed a memory leak in _PyUnicode_Fini().
1529
1530Build issues
1531
1532- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001533 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001534 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001535
1536- The mmap.PAGESIZE constant is now initialized using sysconf when
1537 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1538
1539- The md5 file should now compile on all platforms.
1540
1541- The select module now compiles on platforms that do not define
1542 POLLRDNORM and related constants.
1543
1544- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001545 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001546
Jeremy Hylton10921202000-10-09 18:34:12 +00001547- BeOS: A number of changes were made to the build and installation
1548 process. ar-fake now operates on a directory of object files.
1549 dl_export.h is gone, and its macros now appear on the mwcc command
1550 line during build on PPC BeOS.
1551
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001552- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001553 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001554
1555- Cygwin: Support for shared libraries, Tkinter, and sockets.
1556
1557- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1558
1559Tools and other miscellany
1560
1561- Removed debugging prints from main used with freeze.
1562
Tim Peters46446d62000-10-09 21:19:31 +00001563- IDLE auto-indent no longer crashes when it encounters Unicode
1564 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001565
1566What's new in 2.0 beta 2 (since beta 1)?
1567========================================
1568
1569Core language, builtins, and interpreter
1570
Tim Peters482c0212000-09-26 06:33:09 +00001571- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001572 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001573
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001574- Add -h and -V command line options to print the usage message and
1575 Python version number and exit immediately.
1576
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001577- eval() and exec accept Unicode objects as code parameters.
1578
1579- getattr() and setattr() now also accept Unicode objects for the
1580 attribute name, which are converted to strings using the default
1581 encoding before lookup.
1582
1583- Multiplication on string and Unicode now does proper bounds
1584 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1585 string is too long."
1586
1587- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001588 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001589
Jeremy Hylton1b618592000-09-26 05:32:36 +00001590
1591Standard library and extensions
1592
Guido van Rossum5b08f132001-04-16 02:05:23 +00001593- socket module: the OpenSSL code now adds support for RAND_status()
1594 and EGD (Entropy Gathering Device).
1595
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001596- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001597 argument checking; it still takes no arguments.
1598
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001599- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001600
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001601- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001602
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001603- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001604
1605- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001606 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001607
1608- copy: Copy Unicode objects atomically.
1609
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001610- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001611
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001612- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001613
Fred Drake67233bc2000-09-26 16:40:27 +00001614- dbm: Add get() and setdefault() methods to dbm object. Add constant
1615 `library' to module that names the library used. Added doc strings
1616 and method names to error messages. Uses configure to determine
1617 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1618 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001619
1620- distutils: Update to version 0.9.3.
1621
1622- dl: Add several dl.RTLD_ constants.
1623
1624- fpectl: Now supported on FreeBSD.
1625
1626- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1627 found by the collector will be saved in gc.garbage. This is useful
1628 for debugging a program that creates reference cycles.
1629
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001630- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001631 of HTTP class. Do not close socket on zero-length response. Do not
1632 crash when server sends invalid content-length header.
1633
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001634- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001635
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001636- marshal: When reading a short, sign-extend on platforms where shorts
1637 are bigger than 16 bits. When reading a long, repair the unportable
1638 sign extension that was being done for 64-bit machines. (It assumed
1639 that signed right shift sign-extends.)
1640
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001641- operator: Add contains(), invert(), __invert__() as aliases for
1642 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001643
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001644- os: Add support for popen2() and popen3() on all platforms where
1645 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001646
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001647- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001648 clicking on a file in Explorer (or passing the file name to the
1649 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001650
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001651- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001652 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001653
1654- pickle: Now raises ValueError when an invalid pickle that contains
1655 a non-string repr where a string repr was expected. This behavior
1656 matches cPickle.
1657
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001658- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001659
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001660- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001661
1662- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001663 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001664 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001665
1666- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001667 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001668
1669- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001670 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001671 few cycles during startup since the first call to
1672 setdefaultencoding() will initialize the codec registry and the
1673 encodings package.
1674
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001675- socket: Support for size hint in readlines() method of object returned
1676 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001677
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001678- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001679 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001680 is followed by whitespace.
1681
Tim Petersa3a3a032000-11-30 05:22:44 +00001682- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001683
1684- struct: Check ranges for bytes and shorts.
1685
1686- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001687 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001688
1689- Tkinter: Image objects are now guaranteed to have unique ids. Set
1690 event.delta to zero if Tk version doesn't support mousewheel.
1691 Removed some debugging prints.
1692
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001693- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001694
Fred Drake67233bc2000-09-26 16:40:27 +00001695- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001696 which works around a bug in Norton AntiVirus 2000 that leads directly
1697 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001698
1699- xml: New version detection code allows PyXML to override standard
1700 XML package if PyXML version is greater than 0.6.1.
1701
Fred Drake64bb3802000-09-26 16:21:35 +00001702- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1703 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1704 tree only for nodes which are sufficiently interesting to a specific
1705 application. Does not provide the HTML-specific extensions. Still
1706 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001707
Fred Drake64bb3802000-09-26 16:21:35 +00001708- xml.sax: SAX 2 support for Python, including all the handler
1709 interfaces needed to process XML 1.0 compliant XML. Some
1710 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001711
Fred Drake64bb3802000-09-26 16:21:35 +00001712- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1713 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001714
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001715
Jeremy Hylton1b618592000-09-26 05:32:36 +00001716C API
1717
1718- Add three new convenience functions for module initialization --
1719 PyModule_AddObject(), PyModule_AddIntConstant(), and
1720 PyModule_AddStringConstant().
1721
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001722- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001723 removed and add #error to Python.h if NULL isn't defined after
1724 #include of stdio.h.
1725
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001726- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001727 backwards compatibility (at the source level) with old extensions.
1728
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001729- A wrapper API was added for signal() and sigaction(). Instead of
1730 either function, always use PyOS_getsig() to get a signal handler
1731 and PyOS_setsig() to set one. A new convenience typedef
1732 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001733
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001734- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001735 internal data buffer and size of a string object -- or the default
1736 encoded version of a Unicode object.
1737
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001738- PyString_Size() and PyString_AsString() accept Unicode objects.
1739
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001740- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001741 exists). INT_MAX and LONG_MAX will always be defined, even if
1742 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001743
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001744- PyFloat_FromString takes a second argument, pend, that was
1745 effectively useless. It is now officially useless but preserved for
1746 backwards compatibility. If the pend argument is not NULL, *pend is
1747 set to NULL.
1748
1749- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1750 for the attribute name. See note on getattr() above.
1751
1752- A few bug fixes to argument processing for Unicode.
1753 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1754 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1755 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001756 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001757
1758- Py_BuildValue accepts B format (for bgen-generated code).
1759
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001760
Jeremy Hylton1b618592000-09-26 05:32:36 +00001761Internals
1762
1763- On Unix, fix code for finding Python installation directory so that
1764 it works when argv[0] is a relative path.
1765
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001766- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001767 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001768 rather than by generating a copy of the object.
1769
Tim Peters482c0212000-09-26 06:33:09 +00001770- Several of the internal Unicode tables are much smaller now, and
1771 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001772
Jeremy Hylton97693b02000-09-26 17:42:51 +00001773- In the garbage collector: Fixed bug in collection of tuples. Fixed
1774 bug that caused some instances to be removed from the container set
1775 while they were still live. Fixed parsing in gc.set_debug() for
1776 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001777
1778- Fixed refcount problem in instance deallocation that only occurred
1779 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1780
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001781- On Windows, getpythonregpath is now protected against null data in
1782 registry key.
1783
1784- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001785 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001786
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001787
Jeremy Hylton1b618592000-09-26 05:32:36 +00001788Build and platform-specific issues
1789
1790- Better support of GNU Pth via --with-pth configure option.
1791
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001792- Python/C API now properly exposed to dynamically-loaded extension
1793 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001794
1795- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1796 Don't define MS_SYNC to be zero when it is undefined. Added missing
1797 prototypes in posixmodule.c.
1798
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001799- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001800 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001801
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001802- Fix largefile support on older NetBSD systems and OpenBSD by adding
1803 define for TELL64.
1804
1805
1806Tools and other miscellany
1807
1808- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1809
1810- freeze: The modulefinder now works with 2.0 opcodes.
1811
Tim Petersa3a3a032000-11-30 05:22:44 +00001812- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001813 Move hackery of sys.argv until after the Tk instance has been
1814 created, which allows the application-specific Tkinter
1815 initialization to be executed if present; also pass an explicit
1816 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001817
Jeremy Hylton1b618592000-09-26 05:32:36 +00001818
1819What's new in 2.0 beta 1?
1820=========================
1821
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001822Source Incompatibilities
1823------------------------
1824
1825None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1826such as single-argument append(), connect() and bind(), and changes to
1827str(long) and repr(float).
1828
1829
1830Binary Incompatibilities
1831------------------------
1832
1833- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1834with Python 2.0; these extensions will have to be rebuilt for Python
18352.0.
1836
1837- On Windows, attempting to import a third party extension built for
1838Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1839can do about this. Check your PYTHONPATH environment variable!
1840
1841- Python bytecode files (*.pyc and *.pyo) are not compatible between
1842releases.
1843
1844
1845Overview of Changes Since 1.6
1846-----------------------------
1847
1848There are many new modules (including brand new XML support through
1849the xml package, and i18n support through the gettext module); a list
1850of all new modules is included below. Lots of bugs have been fixed.
1851
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001852The process for making major new changes to the language has changed
1853since Python 1.6. Enhancements must now be documented by a Python
1854Enhancement Proposal (PEP) before they can be accepted.
1855
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001856There are several important syntax enhancements, described in more
1857detail below:
1858
1859 - Augmented assignment, e.g. x += 1
1860
1861 - List comprehensions, e.g. [x**2 for x in range(10)]
1862
1863 - Extended import statement, e.g. import Module as Name
1864
1865 - Extended print statement, e.g. print >> file, "Hello"
1866
1867Other important changes:
1868
1869 - Optional collection of cyclical garbage
1870
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001871Python Enhancement Proposal (PEP)
1872---------------------------------
1873
1874PEP stands for Python Enhancement Proposal. A PEP is a design
1875document providing information to the Python community, or describing
1876a new feature for Python. The PEP should provide a concise technical
1877specification of the feature and a rationale for the feature.
1878
1879We intend PEPs to be the primary mechanisms for proposing new
1880features, for collecting community input on an issue, and for
1881documenting the design decisions that have gone into Python. The PEP
1882author is responsible for building consensus within the community and
1883documenting dissenting opinions.
1884
1885The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001886
1887Augmented Assignment
1888--------------------
1889
1890This must have been the most-requested feature of the past years!
1891Eleven new assignment operators were added:
1892
Guido van Rossume905e952000-09-05 12:42:46 +00001893 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001894
1895For example,
1896
1897 A += B
1898
1899is similar to
1900
1901 A = A + B
1902
1903except that A is evaluated only once (relevant when A is something
1904like dict[index].attr).
1905
1906However, if A is a mutable object, A may be modified in place. Thus,
1907if A is a number or a string, A += B has the same effect as A = A+B
1908(except A is only evaluated once); but if a is a list, A += B has the
1909same effect as A.extend(B)!
1910
1911Classes and built-in object types can override the new operators in
1912order to implement the in-place behavior; the not-in-place behavior is
1913used automatically as a fallback when an object doesn't implement the
1914in-place behavior. For classes, the method name is derived from the
1915method name for the corresponding not-in-place operator by inserting
1916an 'i' in front of the name, e.g. __iadd__ implements in-place
1917__add__.
1918
1919Augmented assignment was implemented by Thomas Wouters.
1920
1921
1922List Comprehensions
1923-------------------
1924
1925This is a flexible new notation for lists whose elements are computed
1926from another list (or lists). The simplest form is:
1927
1928 [<expression> for <variable> in <sequence>]
1929
Guido van Rossum56db0952000-09-06 23:34:25 +00001930For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001931This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001932
1933You can also add a condition:
1934
1935 [<expression> for <variable> in <sequence> if <condition>]
1936
1937For example, [w for w in words if w == w.lower()] would yield the list
1938of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001939than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001940
1941You can also have nested for loops and more than one 'if' clause. For
1942example, here's a function that flattens a sequence of sequences::
1943
1944 def flatten(seq):
1945 return [x for subseq in seq for x in subseq]
1946
1947 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1948
1949This prints
1950
1951 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1952
1953List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001954Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001955
1956
1957Extended Import Statement
1958-------------------------
1959
1960Many people have asked for a way to import a module under a different
1961name. This can be accomplished like this:
1962
1963 import foo
1964 bar = foo
1965 del foo
1966
1967but this common idiom gets old quickly. A simple extension of the
1968import statement now allows this to be written as follows:
1969
1970 import foo as bar
1971
1972There's also a variant for 'from ... import':
1973
1974 from foo import bar as spam
1975
1976This also works with packages; e.g. you can write this:
1977
1978 import test.regrtest as regrtest
1979
1980Note that 'as' is not a new keyword -- it is recognized only in this
1981context (this is only possible because the syntax for the import
1982statement doesn't involve expressions).
1983
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001984Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001985
1986
1987Extended Print Statement
1988------------------------
1989
1990Easily the most controversial new feature, this extension to the print
1991statement adds an option to make the output go to a different file
1992than the default sys.stdout.
1993
1994For example, to write an error message to sys.stderr, you can now
1995write:
1996
1997 print >> sys.stderr, "Error: bad dog!"
1998
1999As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002000evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002001
2002 print >> None, "Hello world"
2003
2004is equivalent to
2005
2006 print "Hello world"
2007
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002008Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002009
2010
2011Optional Collection of Cyclical Garbage
2012---------------------------------------
2013
2014Python is now equipped with a garbage collector that can hunt down
2015cyclical references between Python objects. It's no replacement for
2016reference counting; in fact, it depends on the reference counts being
2017correct, and decides that a set of objects belong to a cycle if all
2018their reference counts can be accounted for from their references to
2019each other. This devious scheme was first proposed by Eric Tiedemann,
2020and brought to implementation by Neil Schemenauer.
2021
2022There's a module "gc" that lets you control some parameters of the
2023garbage collection. There's also an option to the configure script
2024that lets you enable or disable the garbage collection. In 2.0b1,
2025it's on by default, so that we (hopefully) can collect decent user
2026experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002027performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002028off by default in the final 2.0 release.
2029
2030
2031Smaller Changes
2032---------------
2033
2034A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2035map(None, seq1, seq2, ...) when the sequences have the same length;
2036i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2037the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002038zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002039
2040sys.version_info is a tuple (major, minor, micro, level, serial).
2041
2042Dictionaries have an odd new method, setdefault(key, default).
2043dict.setdefault(key, default) returns dict[key] if it exists; if not,
2044it sets dict[key] to default and returns that value. Thus:
2045
2046 dict.setdefault(key, []).append(item)
2047
2048does the same work as this common idiom:
2049
2050 if not dict.has_key(key):
2051 dict[key] = []
2052 dict[key].append(item)
2053
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002054There are two new variants of SyntaxError that are raised for
2055indentation-related errors: IndentationError and TabError.
2056
2057Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2058escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002059
2060The limits on the size of expressions and file in Python source code
2061have been raised from 2**16 to 2**32. Previous versions of Python
2062were limited because the maximum argument size the Python VM accepted
2063was 2**16. This limited the size of object constructor expressions,
2064e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2065limit was raised thanks to a patch by Charles Waldman that effectively
2066fixes the problem. It is now much more likely that you will be
2067limited by available memory than by an arbitrary limit in Python.
2068
2069The interpreter's maximum recursion depth can be modified by Python
2070programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2071limit is the maximum number of recursive calls that can be made by
2072Python code. The limit exists to prevent infinite recursion from
2073overflowing the C stack and causing a core dump. The default value is
20741000. The maximum safe value for a particular platform can be found
2075by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002076
2077New Modules and Packages
2078------------------------
2079
2080atexit - for registering functions to be called when Python exits.
2081
2082imputil - Greg Stein's alternative API for writing custom import
2083hooks.
2084
2085pyexpat - an interface to the Expat XML parser, contributed by Paul
2086Prescod.
2087
2088xml - a new package with XML support code organized (so far) in three
2089subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2090would fill a volume. There's a special feature whereby a
2091user-installed package named _xmlplus overrides the standard
2092xmlpackage; this is intended to give the XML SIG a hook to distribute
2093backwards-compatible updates to the standard xml package.
2094
2095webbrowser - a platform-independent API to launch a web browser.
2096
2097
Guido van Rossume905e952000-09-05 12:42:46 +00002098Changed Modules
2099---------------
2100
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002101array -- new methods for array objects: count, extend, index, pop, and
2102remove
2103
2104binascii -- new functions b2a_hex and a2b_hex that convert between
2105binary data and its hex representation
2106
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002107calendar -- Many new functions that support features including control
2108over which day of the week is the first day, returning strings instead
2109of printing them. Also new symbolic constants for days of week,
2110e.g. MONDAY, ..., SUNDAY.
2111
2112cgi -- FieldStorage objects have a getvalue method that works like a
2113dictionary's get method and returns the value attribute of the object.
2114
2115ConfigParser -- The parser object has new methods has_option,
2116remove_section, remove_option, set, and write. They allow the module
2117to be used for writing config files as well as reading them.
2118
2119ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002120optionally support the RFC 959 REST command.
2121
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002122gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002123
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002124httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2125the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002126
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002127locale -- implement getdefaultlocale for Win32 and Macintosh
2128
2129marshal -- no longer dumps core when marshaling deeply nested or
2130recursive data structures
2131
2132os -- new functions isatty, seteuid, setegid, setreuid, setregid
2133
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002134os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2135support under Unix.
2136
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002137os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002138
2139os.path -- fix semantics of os.path.commonprefix
2140
2141smtplib -- support for sending very long messages
2142
2143socket -- new function getfqdn()
2144
2145readline -- new functions to read, write and truncate history files.
2146The readline section of the library reference manual contains an
2147example.
2148
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002149select -- add interface to poll system call
2150
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002151shutil -- new copyfileobj function
2152
2153SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2154HTTP server.
2155
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002156Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002157
2158urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002159e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002160
2161whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002162
2163
2164Obsolete Modules
2165----------------
2166
2167None. However note that 1.6 made a whole slew of modules obsolete:
2168stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2169poly, zmod, strop, util, whatsound.
2170
2171
2172Changed, New, Obsolete Tools
2173----------------------------
2174
Tim Peters8b092332000-09-05 20:15:25 +00002175None.
Guido van Rossume905e952000-09-05 12:42:46 +00002176
2177
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002178C-level Changes
2179---------------
2180
2181Several cleanup jobs were carried out throughout the source code.
2182
2183All C code was converted to ANSI C; we got rid of all uses of the
2184Py_PROTO() macro, which makes the header files a lot more readable.
2185
2186Most of the portability hacks were moved to a new header file,
2187pyport.h; several other new header files were added and some old
2188header files were removed, in an attempt to create a more rational set
2189of header files. (Few of these ever need to be included explicitly;
2190they are all included by Python.h.)
2191
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002192Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002193and Win64, especially for the new Intel Itanium processor. Mick also
2194added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002195
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002196The C APIs to return an object's size have been update to consistently
2197use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2198previous versions, the abstract interfaces used PyXXX_Length and the
2199concrete interfaces used PyXXX_Size. The old names,
2200e.g. PyObject_Length, are still available for backwards compatibility
2201at the API level, but are deprecated.
2202
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002203The PyOS_CheckStack function has been implemented on Windows by
2204Fredrik Lundh. It prevents Python from failing with a stack overflow
2205on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002206
2207The GC changes resulted in creation of two new slots on object,
2208tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002209the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002210
2211The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002212C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002213
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002214PyErr_Format has been updated to automatically calculate the size of
2215the buffer needed to hold the formatted result string. This change
2216prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002217
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002218New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002219
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002220PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2221that are the same as their non-Ex counterparts except they take an
2222extra flag argument that tells them to close the file when done.
2223
2224XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002225
Tim Peters8b092332000-09-05 20:15:25 +00002226
2227Windows Changes
2228---------------
2229
2230New popen2/popen3/peopen4 in os module (see Changed Modules above).
2231
2232os.popen is much more usable on Windows 95 and 98. See Microsoft
2233Knowledge Base article Q150956. The Win9x workaround described there
2234is implemented by the new w9xpopen.exe helper in the root of your
2235Python installation. Note that Python uses this internally; it is not
2236a standalone program.
2237
2238Administrator privileges are no longer required to install Python
2239on Windows NT or Windows 2000. If you have administrator privileges,
2240Python's registry info will be written under HKEY_LOCAL_MACHINE.
2241Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002242under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002243uses of Python, but will prevent some advanced uses from working
2244(for example, running a Python script as an NT service, or possibly
2245from CGI).
2246
2247[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2248installer; instead, it installs the needed Tcl/Tk files directly in the
2249Python directory. If you already have a Tcl/Tk installation, this
2250wastes some disk space (about 4 Megs) but avoids problems with
2251conflicting Tcl/Tk installations, and makes it much easier for Python
2252to ensure that Tcl/Tk can find all its files.
2253
2254[This was new in 1.6] The Windows installer now installs by default in
2255\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2256
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002257
2258Updates to the changes between 1.5.2 and 1.6
2259--------------------------------------------
2260
2261The 1.6 NEWS file can't be changed after the release is done, so here
2262is some late-breaking news:
2263
2264New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2265and changes to getlocale() and setlocale().
2266
2267The new module is now enabled per default.
2268
2269It is not true that the encodings codecs cannot be used for normal
2270strings: the string.encode() (which is also present on 8-bit strings
2271!) allows using them for 8-bit strings too, e.g. to convert files from
2272cp1252 (Windows) to latin-1 or vice-versa.
2273
2274Japanese codecs are available from Tamito KAJIYAMA:
2275http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2276
2277
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002278======================================================================