blob: 55e29930c941026ab5c4fed918f1bdcaf75b8d74 [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 Petersb7da0902001-09-02 23:01:43 +000098- Stephen Hansen contributed patches sufficient to get a clean compile
99 under Borland C (Windows), but he reports problems running it and ran
100 out of time to complete the port. Volunteers? Expect a MemoryError
101 when importing the types module; this is probably shallow, and
102 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000103
Tim Petersedc99312001-08-22 21:36:50 +0000104Tests
105
106Windows
107
Tim Petersbdee63f2001-09-02 03:40:59 +0000108- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000109 points to command.com (patch from Brian Quinlan).
110
Tim Petersedc99312001-08-22 21:36:50 +0000111
Tim Peters20f51a72001-07-21 02:31:40 +0000112What's New in Python 2.2a2?
113===========================
114
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000115Build
116
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000117- Tim Peters developed a brand new Windows installer using Wise 8.1,
118 generously donated to us by Wise Solutions.
119
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000120- configure supports a new option --enable-unicode, with the values
121 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
122 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000123
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000124- A new configure option --enable-framework builds a Mac OS X framework,
125 which "make frameworkinstall" will install. This provides a starting
126 point for more mac-like functionality, join pythonmac-sig@python.org
127 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000128
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000129- The NeXT platform is no longer supported.
130
131- The `new' module is now statically linked.
132
Tim Peters0afb6092001-08-15 06:06:44 +0000133Tools
134
135- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000136 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000137 the module docstring for details.
138
Tim Peters20f51a72001-07-21 02:31:40 +0000139Tests
140
Tim Peters5e824c32001-08-12 22:25:01 +0000141- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000142 platforms, allowing to give clearer test result output. regrtest
143 also has optional --use/-u switch to run normally disabled tests
144 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000145
Tim Peters20f51a72001-07-21 02:31:40 +0000146- Several new tests in the standard test suite, with special thanks to
147 Nick Mathewson.
148
149Core
150
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000151- The floor division operator // has been added as outlined in PEP
152 238. The / operator still provides classic division (and will until
153 Python 3.0) unless "from __future__ import division" is included, in
154 which case the / operator will provide true division. The operator
155 module provides truediv() and floordiv() functions. Augmented
156 assignment variants are included, as are the equivalent overloadable
157 methods and C API methods. See the PEP for a full discussion:
158 <http://python.sf.net/peps/pep-0238.html>
159
Tim Peters6cd6a822001-08-17 22:11:27 +0000160- Future statements are now effective in simulated interactive shells
161 (like IDLE). This should "just work" by magic, but read Michael
162 Hudson's "Future statements in simulated shells" PEP 264 for full
163 details: <http://python.sf.net/peps/pep-0264.html>.
164
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000165- The type/class unification (PEP 252-253) was integrated into the
166 trunk and is not so tentative any more (the exact specification of
167 some features is still tentative). A lot of work has done on fixing
168 bugs and adding robustness and features (performance still has to
169 come a long way).
170
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000171- Warnings about a mismatch in the Python API during extension import
172 now use the Python warning framework (which makes it possible to
173 write filters for these warnings).
174
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000175- A function's __dict__ (aka func_dict) will now always be a
176 dictionary. It used to be possible to delete it or set it to None,
177 but now both actions raise TypeErrors. It is still legal to set it
178 to a dictionary object. Getting func.__dict__ before any attributes
179 have been assigned now returns an empty dictionary instead of None.
180
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000181Library
182
Tim Peters5e824c32001-08-12 22:25:01 +0000183- New class Differ and new functions ndiff() and restore() in difflib.py.
184 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000185 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000186
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000187- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
188 value using the minimal quoting required for the value; more
189 reliable than using xml.sax.saxutils.escape() for attribute values.
190
191- Readline completion support for cmd.Cmd was added.
192
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000193- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
194
195- Added function threading.BoundedSemaphore()
196
197- Added Ka-Ping Yee's cgitb.py module.
198
199- The `new' module now exposes the CO_xxx flags.
200
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000201New platforms
202
203C API
204
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000205- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
206 which provide a cross-platform implementations for the
207 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
208 the standard sprintf() and vsprintf() C lib APIs, these versions
209 apply bounds checking on the used buffer which enhances protection
210 against buffer overruns.
211
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000212- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000213 and extensions using different Unicode widths is rendered next to
214 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000215 will result in an ImportError. Unicode extensions writers must make
216 sure to check the Unicode width compatibility in their extensions by
217 using at least one of the mangled Unicode APIs in the extension.
218
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000219- Two new flags METH_NOARGS and METH_O are available in method definition
220 tables to simplify implementation of methods with no arguments and a
221 single untyped argument. Calling such methods is more efficient than
222 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
223 deprecated.
224
Tim Petersc1731372001-08-04 08:12:36 +0000225Windows
226
227- "import module" now compiles module.pyw if it exists and nothing else
228 relevant is found.
229
Tim Peters20f51a72001-07-21 02:31:40 +0000230
Guido van Rossum55a78992001-07-17 17:22:32 +0000231What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000232===========================
233
234Core
Tim Petersa814db52001-05-14 07:05:58 +0000235
Tim Peters6d6c1a32001-08-02 04:15:00 +0000236- TENTATIVELY, a large amount of code implementing much of what's
237 described in PEP 252 (Making Types Look More Like Classes) and PEP
238 253 (Subtyping Built-in Types) was added. This will be released
239 with Python 2.2a1. Documentation will be provided separately
240 through http://www.python.org/2.2/. The purpose of releasing this
241 with Python 2.2a1 is to test backwards compatibility. It is
242 possible, though not likely, that a decision is made not to release
243 this code as part of 2.2 final, if any serious backwards
244 incompapatibilities are found during alpha testing that cannot be
245 repaired.
246
Guido van Rossum55a78992001-07-17 17:22:32 +0000247- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000248 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000249 more 'yield' statements. See PEP 255. Since this adds a new
250 keyword to the language, this feature must be enabled by including a
251 future statement: "from __future__ import generators" (see PEP 236).
252 Generators will become a standard feature in a future release
253 (probably 2.3). Without this future statement, 'yield' remains an
254 ordinary identifier, but a warning is issued each time it is used.
255 (These warnings currently don't conform to the warnings framework of
256 PEP 230; we intend to fix this in 2.2a2.)
257
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000258- The UTF-16 codec was modified to be more RFC compliant. It will now
259 only remove BOM characters at the start of the string and then
260 only if running in native mode (UTF-16-LE and -BE won't remove a
261 leading BMO character).
262
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000263- Strings now have a new method .decode() to complement the already
264 existing .encode() method. These two methods provide direct access
265 to the corresponding decoders and encoders of the registered codecs.
266
267 To enhance the usability of the .encode() method, the special
268 casing of Unicode object return values was dropped (Unicode objects
269 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000270
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000271 Both methods will now return whatever the codec in charge of the
272 requested encoding returns as object, e.g. Unicode codecs will
273 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
274 will return u"äöü"). This enables codec writer to create codecs
275 for various simple to use conversions.
276
277 New codecs were added to demonstrate these new features (the .encode()
278 and .decode() columns indicate the type of the returned objects):
279
280 Name | .encode() | .decode() | Description
281 ----------------------------------------------------------------------
282 uu | string | string | UU codec (e.g. for email)
283 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000284 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000285 zlib | string | string | zlib compression
286 hex | string | string | 2-byte hex codec
287 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
288
Mark Hammond2a0af792001-05-14 03:09:36 +0000289- Some operating systems now support the concept of a default Unicode
290 encoding for file system operations. Notably, Windows supports 'mbcs'
291 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000292 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000293 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000294
295 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000296 functions that return filenames (such as os.listdir()) to return Python
297 string objects pre-encoded using the default file system encoding for
298 the platform. As this encoding is likely to be different from Python's
299 default encoding, converting this name to a Unicode object before passing
300 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000301 would attempt to use its default encoding (generally ASCII) rather than
302 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000303
Tim Petersa814db52001-05-14 07:05:58 +0000304 In general, this change simply removes surprises when working with
305 Unicode and the file system, making these operations work as you expect,
306 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000307 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000308
Tim Peters61dff2b2001-05-08 15:43:37 +0000309- Float (and complex) literals in source code were evaluated to full
310 precision only when running from a .py file; the same code loaded from a
311 .pyc (or .pyo) file could suffer numeric differences starting at about the
312 12th significant decimal digit. For example, on a machine with IEEE-754
313 floating arithmetic,
314
315 x = 9007199254740992.0
316 print long(x)
317
318 printed 9007199254740992 if run directly from .py, but 9007199254740000
319 if from a compiled (.pyc or .pyo) file. This was due to marshal using
320 str(float) instead of repr(float) when building code objects. marshal
321 now uses repr(float) instead, which should reproduce floats to full
322 machine precision (assuming the platform C float<->string I/O conversion
323 functions are of good quality).
324
325 This may cause floating-point results to change in some cases, and
326 usually for the better, but may also cause numerically unstable
327 algorithms to break.
328
Tim Peters2f228e72001-05-13 00:19:31 +0000329- The implementation of dicts suffers fewer collisions, which has speed
330 benefits. However, the order in which dict entries appear in dict.keys(),
331 dict.values() and dict.items() may differ from previous releases for a
332 given dict. Nothing is defined about this order, so no program should
333 rely on it. Nevertheless, it's easy to write test cases that rely on the
334 order by accident, typically because of printing the str() or repr() of a
335 dict to an "expected results" file. See Lib/test/test_support.py's new
336 sortdict(dict) function for a simple way to display a dict in sorted
337 order.
338
Tim Peters7a3bfc32001-06-12 01:22:22 +0000339- Many other small changes to dicts were made, resulting in faster
340 operation along the most common code paths.
341
Guido van Rossum10315822001-05-01 20:54:30 +0000342- Dictionary objects now support the "in" operator: "x in dict" means
343 the same as dict.has_key(x).
344
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000345- The update() method of dictionaries now accepts generic mapping
346 objects. Specifically the argument object must support the .keys()
347 and __getitem__() methods. This allows you to say, for example,
348 {}.update(UserDict())
349
Guido van Rossum10315822001-05-01 20:54:30 +0000350- Iterators were added; this is a generalized way of providing values
351 to a for loop. See PEP 234. There's a new built-in function iter()
352 to return an iterator. There's a new protocol to get the next value
353 from an iterator using the next() method (in Python) or the
354 tp_iternext slot (in C). There's a new protocol to get iterators
355 using the __iter__() method (in Python) or the tp_iter slot (in C).
356 Iterating (i.e. a for loop) over a dictionary generates its keys.
357 Iterating over a file generates its lines.
358
Tim Petersf553f892001-05-01 20:45:31 +0000359- The following functions were generalized to work nicely with iterator
360 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000361 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000362 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
363 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000364 join() method of strings
365 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000366 'x in y' and 'x not in y' (PySequence_Contains() in C API)
367 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000368 right-hand side of assignment statements with multiple targets, such as
369 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000370
Tim Petersd85e1022001-05-11 21:51:48 +0000371- Accessing module attributes is significantly faster (for example,
372 random.random or os.path or yourPythonModule.yourAttribute).
373
Tim Peterse63415e2001-05-08 04:38:29 +0000374- Comparing dictionary objects via == and != is faster, and now works even
375 if the keys and values don't support comparisons other than ==.
376
Tim Peters95bf9392001-05-10 08:32:44 +0000377- Comparing dictionaries in ways other than == and != is slower: there were
378 insecurities in the dict comparison implementation that could cause Python
379 to crash if the element comparison routines for the dict keys and/or
380 values mutated the dicts. Making the code bulletproof slowed it down.
381
Tim Peterseb28ef22001-06-02 05:27:19 +0000382- Collisions in dicts are resolved via a new approach, which can help
383 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000384 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000385 faster now. Thanks to Christian Tismer for pointing out the cause and
386 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000387
Tim Peters52e155e2001-06-16 05:42:57 +0000388- repr() is much faster for large containers (dict, list, tuple).
389
390
Tim Petersa814db52001-05-14 07:05:58 +0000391Library
392
Fred Drake960fdf92001-07-20 18:38:26 +0000393- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
394 were added to the string module. These a locale-indenpendent
395 constants, unlike letters, lowercase, and uppercase. These are now
396 use in appropriate locations in the standard library.
397
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000398- The flags used in dlopen calls can now be configured using
399 sys.setdlopenflags and queried using sys.getdlopenflags.
400
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000401- Fredrik Lundh's xmlrpclib is now a standard library module. This
402 provides full client-side XML-RPC support. In addition,
403 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
404 one asyncore-based). Thanks to Eric Raymond for the documentation.
405
Guido van Rossum643d3912001-07-05 14:46:25 +0000406- The xrange() object is simplified: it no longer supports slicing,
407 repetition, comparisons, efficient 'in' checking, the tolist()
408 method, or the start, stop and step attributes. See PEP 260.
409
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000410- A new function fnmatch.filter to filter lists of file names was added.
411
Barry Warsawffd674d2001-05-22 16:00:10 +0000412- calendar.py uses month and day names based on the current locale.
413
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000414- strop is now *really* obsolete (this was announced before with 1.6),
415 and issues DeprecationWarning when used (except for the four items
416 that are still imported into string.py).
417
Tim Petersa814db52001-05-14 07:05:58 +0000418- Cookie.py now sorts key+value pairs by key in output strings.
419
420- pprint.isrecursive(object) didn't correctly identify recursive objects.
421 Now it does.
422
Tim Peters95b3f782001-05-14 18:39:41 +0000423- pprint functions now much faster for large containers (tuple, list, dict).
424
Tim Peters7b9542a2001-06-10 23:40:19 +0000425- New 'q' and 'Q' format codes in the struct module, corresponding to C
426 types "long long" and "unsigned long long" (on Windows, __int64). In
427 native mode, these can be used only when the platform C compiler supports
428 these types (when HAVE_LONG_LONG is #define'd by the Python config
429 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000430 In standard mode, 'q' and 'Q' are supported on all platforms, and are
431 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000432
Guido van Rossum83213cc2001-06-12 16:48:52 +0000433- The site module installs a new built-in function 'help' that invokes
434 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
435 it displays a message reminding the user to use 'help()' or
436 'help(object)'.
437
Tim Petersa814db52001-05-14 07:05:58 +0000438Tests
439
440- New test_mutants.py runs dict comparisons where the key and value
441 comparison operators mutute the dicts randomly during comparison. This
442 rapidly causes Python to crash under earlier releases (not for the faint
443 of heart: it can also cause Win9x to freeze or reboot!).
444
445- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000446 pprint.isreadable() return sensible results. Also verifies that simple
447 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000448
Tim Peters4324aa32001-05-28 22:30:08 +0000449C API
450
451- Removed the unused last_is_sticky argument from the internal
452 _PyTuple_Resize(). If this affects you, you were cheating.
453
454
Guido van Rossum55a78992001-07-17 17:22:32 +0000455======================================================================
456
457
Guido van Rossumffe13be2001-04-16 18:46:45 +0000458What's New in Python 2.1 (final)?
459=================================
460
461We only changed a few things since the last release candidate, all in
462Python library code:
463
464- A bug in the locale module was fixed that affected locales which
465 define no grouping for numeric formatting.
466
467- A few bugs in the weakref module's implementations of weak
468 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
469 and the test suite was updated to check for these bugs.
470
471- An old bug in the os.path.walk() function (introduced in Python
472 2.0!) was fixed: a non-existent file would cause an exception
473 instead of being ignored.
474
475- Fixed a few bugs in the new symtable module found by Neil Norwitz's
476 PyChecker.
477
478
Guido van Rossum5b08f132001-04-16 02:05:23 +0000479What's New in Python 2.1c2?
480===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000481
Guido van Rossum5b08f132001-04-16 02:05:23 +0000482A flurry of small changes, and one showstopper fixed in the nick of
483time made it necessary to release another release candidate. The list
484here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000485
Guido van Rossum5b08f132001-04-16 02:05:23 +0000486Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000487
Guido van Rossum5b08f132001-04-16 02:05:23 +0000488- Tim discovered a nasty bug in the dictionary code, caused by
489 PyDict_Next() calling dict_resize(), and the GC code's use of
490 PyDict_Next() violating an assumption in dict_items(). This was
491 fixed with considerable amounts of band-aid, but the net effect is a
492 saner and more robust implementation.
493
494- Made a bunch of symbols static that were accidentally global.
495
496Build and Ports
497
498- The setup.py script didn't check for a new enough version of zlib
499 (1.1.3 is needed). Now it does.
500
501- Changed "make clean" target to also remove shared libraries.
502
503- Added a more general warning about the SGI Irix optimizer to README.
504
505Library
506
507- Fix a bug in urllib.basejoin("http://host", "../file.html") which
508 omitted the slash between host and file.html.
509
510- The mailbox module's _Mailbox class contained a completely broken
511 and undocumented seek() method. Ripped it out.
512
513- Fixed a bunch of typos in various library modules (urllib2, smtpd,
514 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
515
516- Fixed a few last-minute bugs in unittest.
517
518Extensions
519
520- Reverted the patch to the OpenSSL code in socketmodule.c to support
521 RAND_status() and the EGD, and the subsequent patch that tried to
522 fix it for pre-0.9.5 versions; the problem with the patch is that on
523 some systems it issues a warning whenever socket is imported, and
524 that's unacceptable.
525
526Tests
527
528- Fixed the pickle tests to work with "import test.test_pickle".
529
530- Tweaked test_locale.py to actually run the test Windows.
531
532- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
533 not "wb" (which is not a valid mode at all).
534
535- Fix pstats browser crashes. Import readline if it exists to make
536 the user interface nicer.
537
538- Add "import thread" to the top of test modules that import the
539 threading module (test_asynchat and test_threadedtempfile). This
540 prevents test failures caused by a broken threading module resulting
541 from a previously caught failed import.
542
543- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
544 needed on some platforms (e.g. Solaris 8) when the tests are run
545 twice in succession.
546
547- Skip rather than fail test_sunaudiodev if no audio device is found.
548
549
550What's New in Python 2.1c1?
551===========================
552
553This list was significantly updated when 2.1c2 was released; the 2.1c1
554release didn't mention most changes that were actually part of 2.1c1:
555
556Legal
557
558- Copyright was assigned to the Python Software Foundation (PSF) and a
559 PSF license (very similar to the CNRI license) was added.
560
561- The CNRI copyright notice was updated to include 2001.
562
563Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000564
Guido van Rossumc9932722001-04-12 02:31:27 +0000565- After a public outcry, assignment to __debug__ is no longer illegal;
566 instead, a warning is issued. It will become illegal in 2.2.
567
Guido van Rossum5b08f132001-04-16 02:05:23 +0000568- Fixed a core dump with "%#x" % 0, and changed the semantics so that
569 "%#x" now always prepends "0x", even if the value is zero.
570
571- Fixed some nits in the bytecode compiler.
572
573- Fixed core dumps when calling certain kinds of non-functions.
574
575- Fixed various core dumps caused by reference count bugs.
576
577Build and Ports
578
579- Use INSTALL_SCRIPT to install script files.
580
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000581- New port: SCO Unixware 7, by Billy G. Allie.
582
Guido van Rossum5b08f132001-04-16 02:05:23 +0000583- Updated RISCOS port.
584
585- Updated BeOS port and notes.
586
587- Various other porting problems resolved.
588
589Library
590
591- The TERMIOS and SOCKET modules are now truly obsolete and
592 unnecessary. Their symbols are incorporated in the termios and
593 socket modules.
594
595- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
596 better tests for pickling.
597
598- threading: make Condition.wait() robust against KeyboardInterrupt.
599
600- zipfile: add support to zipfile to support opening an archive
601 represented by an open file rather than a file name. Fix bug where
602 the archive was not properly closed. Fixed a bug in this bugfix
603 where flush() was called for a read-only file.
604
605- imputil: added an uninstall() method to the ImportManager.
606
607- Canvas: fixed bugs in lower() and tkraise() methods.
608
609- SocketServer: API change (added overridable close_request() method)
610 so that the TCP server can explicitly close the request.
611
612- pstats: Eric Raymond added a simple interactive statistics browser,
613 invoked when the module is run as a script.
614
615- locale: fixed a problem in format().
616
617- webbrowser: made it work when the BROWSER environment variable has a
618 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
619 KDE 2. Fixed some other nits.
620
621- unittest: changes to allow using a different exception than
622 AssertionError, and added a few more function aliases. Some other
623 small changes.
624
625- urllib, urllib2: fixed redirect problems and a coupleof other nits.
626
627- asynchat: fixed a critical bug in asynchat that slipped through the
628 2.1b2 release. Fixed another rare bug.
629
630- Fix some unqualified except: clauses (always a bad code example).
631
632XML
633
634- pyexpat: new API get_version_string().
635
636- Fixed some minidom bugs.
637
638Extensions
639
640- Fixed a core dump in _weakref. Removed the weakref.mapping()
641 function (it adds nothing to the API).
642
643- Rationalized the use of header files in the readline module, to make
644 it compile (albeit with some warnings) with the very recent readline
645 4.2, without breaking for earlier versions.
646
647- Hopefully fixed a buffering problem in linuxaudiodev.
648
649- Attempted a fix to make the OpenSSL support in the socket module
650 work again with pre-0.9.5 versions of OpenSSL.
651
652Tests
653
654- Added a test case for asynchat and asyncore.
655
656- Removed coupling between tests where one test failing could break
657 another.
658
659Tools
660
661- Ping added an interactive help browser to pydoc, fixed some nits
662 in the rest of the pydoc code, and added some features to his
663 inspect module.
664
665- An updated python-mode.el version 4.1 which integrates Ken
666 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
667 much nicer in XEmacs and Emacs. When stepping through your program
668 with pdb, in either the shell window or the *Python* window, the
669 source file and line will be tracked by an arrow. Very cool!
670
671- IDLE: syntax warnings in interactive mode are changed into errors.
672
673- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000674 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000675
676- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000677
Barry Warsaw11e89c72001-04-11 20:37:57 +0000678
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000679What's New in Python 2.1 beta 2?
680================================
681
Guido van Rossum053ae352001-03-22 14:17:21 +0000682(Unlisted are many fixed bugs, more documentation, etc.)
683
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000684Core language, builtins, and interpreter
685
Guido van Rossum053ae352001-03-22 14:17:21 +0000686- The nested scopes work (enabled by "from __future__ import
687 nested_scopes") is completed; in particular, the future now extends
688 into code executed through exec, eval() and execfile(), and into the
689 interactive interpreter.
690
691- When calling a base class method (e.g. BaseClass.__init__(self)),
692 this is now allowed even if self is not strictly spoken a class
693 instance (e.g. when using metaclasses or the Don Beaudry hook).
694
695- Slice objects are now comparable but not hashable; this prevents
696 dict[:] from being accepted but meaningless.
697
698- Complex division is now calculated using less braindead algorithms.
699 This doesn't change semantics except it's more likely to give useful
700 results in extreme cases. Complex repr() now uses full precision
701 like float repr().
702
703- sgmllib.py now calls handle_decl() for simple <!...> declarations.
704
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000705- It is illegal to assign to the name __debug__, which is set when the
706 interpreter starts. It is effectively a compile-time constant.
707
708- A warning will be issued if a global statement for a variable
709 follows a use or assignment of that variable.
710
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000711Standard library
712
Guido van Rossum053ae352001-03-22 14:17:21 +0000713- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
714 inspired by JUnit), is now part of the standard library. You now
715 have a choice of two testing frameworks: unittest requires you to
716 write testcases as separate code, doctest gathers them from
717 docstrings. Both approaches have their advantages and
718 disadvantages.
719
720- A new module Tix was added, which wraps the Tix extension library
721 for Tk. With that module, it is not necessary to statically link
722 Tix with _tkinter, since Tix will be loaded with Tcl's "package
723 require" command. See Demo/tix/.
724
725- tzparse.py is now obsolete.
726
727- In gzip.py, the seek() and tell() methods are removed -- they were
728 non-functional anyway, and it's better if callers can test for their
729 existence with hasattr().
730
731Python/C API
732
733- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
734 that's already in the dictionary during a PyDict_Next() iteration.
735 This used to fail occasionally when a dictionary resize operation
736 could be triggered that would rehash all the keys. All other
737 modifications to the dictionary are still off-limits during a
738 PyDict_Next() iteration!
739
740- New extended APIs related to passing compiler variables around.
741
742- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
743 implement isinstance() and issubclass().
744
745- Py_BuildValue() now has a "D" conversion to create a Python complex
746 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000747
Fred Drake4e262a92001-03-22 18:26:47 +0000748- Extensions types which support weak references must now set the
749 field allocated for the weak reference machinery to NULL themselves;
750 this is done to avoid the cost of checking each object for having a
751 weakly referencable type in PyObject_INIT(), since most types are
752 not weakly referencable.
753
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000754- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
755 free variables and cell variables to and from the frame's f_locals.
756
757- Variants of several functions defined in pythonrun.h have been added
758 to support the nested_scopes future statement. The variants all end
759 in Flags and take an extra argument, a PyCompilerFlags *; examples:
760 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
761 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000762 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000763
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000764Distutils
765
766- the sdist command now writes a PKG-INFO file, as described in PEP 241,
767 into the release tree.
768
Tim Peters0e57abf2001-05-02 07:39:38 +0000769- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000770 (an uninstaller, more customization of the installer's display)
771
772- from Jack Jansen: added Mac-specific code to generate a dialog for
773 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000774 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000775 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000776
777- added 'platforms' and 'keywords' to the set of metadata that can be
778 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000779
780- applied patches from Jason Tishler to make the compiler class work with
781 Cygwin.
782
783
Tim Peters2fe289a2001-03-01 22:19:38 +0000784What's New in Python 2.1 beta 1?
785================================
Tim Petersd66595f2001-02-04 03:09:53 +0000786
787Core language, builtins, and interpreter
788
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000789- Following an outcry from the community about the amount of code
790 broken by the nested scopes feature introduced in 2.1a2, we decided
791 to make this feature optional, and to wait until Python 2.2 (or at
792 least 6 months) to make it standard. The option can be enabled on a
793 per-module basis by adding "from __future__ import nested_scopes" at
794 the beginning of a module (before any other statements, but after
795 comments and an optional docstring). See PEP 236 (Back to the
796 __future__) for a description of the __future__ statement. PEP 227
797 (Statically Nested Scopes) has been updated to reflect this change,
798 and to clarify the semantics in a number of endcases.
799
800- The nested scopes code, when enabled, has been hardened, and most
801 bugs and memory leaks in it have been fixed.
802
803- Compile-time warnings are now generated for a number of conditions
804 that will break or change in meaning when nested scopes are enabled:
805
806 - Using "from...import *" or "exec" without in-clause in a function
807 scope that also defines a lambda or nested function with one or
808 more free (non-local) variables. The presence of the import* or
809 bare exec makes it impossible for the compiler to determine the
810 exact set of local variables in the outer scope, which makes it
811 impossible to determine the bindings for free variables in the
812 inner scope. To avoid the warning about import *, change it into
813 an import of explicitly name object, or move the import* statement
814 to the global scope; to avoid the warning about bare exec, use
815 exec...in... (a good idea anyway -- there's a possibility that
816 bare exec will be deprecated in the future).
817
818 - Use of a global variable in a nested scope with the same name as a
819 local variable in a surrounding scope. This will change in
820 meaning with nested scopes: the name in the inner scope will
821 reference the variable in the outer scope rather than the global
822 of the same name. To avoid the warning, either rename the outer
823 variable, or use a global statement in the inner function.
824
Neil Schemenauera35c6882001-02-27 04:45:05 +0000825- An optional object allocator has been included. This allocator is
826 optimized for Python objects and should be faster and use less memory
827 than the standard system allocator. It is not enabled by default
828 because of possible thread safety problems. The allocator is only
829 protected by the Python interpreter lock and it is possible that some
830 extension modules require a thread safe allocator. The object
831 allocator can be enabled by providing the "--with-pymalloc" option to
832 configure.
833
Tim Petersd66595f2001-02-04 03:09:53 +0000834Standard library
835
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000836- pyexpat now detects the expat version if expat.h defines it. A
837 number of additional handlers are provided, which are only available
838 since expat 1.95. In addition, the methods SetParamEntityParsing and
839 GetInputContext of Parser objects are available with 1.95.x
840 only. Parser objects now provide the ordered_attributes and
841 specified_attributes attributes. A new module expat.model was added,
842 which offers a number of additional constants if 1.95.x is used.
843
844- xml.dom offers the new functions registerDOMImplementation and
845 getDOMImplementation.
846
847- xml.dom.minidom offers a toprettyxml method. A number of DOM
848 conformance issues have been resolved. In particular, Element now
849 has an hasAttributes method, and the handling of namespaces was
850 improved.
851
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000852- Ka-Ping Yee contributed two new modules: inspect.py, a module for
853 getting information about live Python code, and pydoc.py, a module
854 for interactively converting docstrings to HTML or text.
855 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000856 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000857 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
858 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000859
Tim Peters1eff7962001-03-01 02:31:33 +0000860- New library module difflib.py, primarily packaging the SequenceMatcher
861 class at the heart of the popular ndiff.py file-comparison tool.
862
863- doctest.py (a framework for verifying Python code examples in docstrings)
864 is now part of the std library.
865
Tim Petersd66595f2001-02-04 03:09:53 +0000866Windows changes
867
Guido van Rossume3955a82001-03-02 14:05:59 +0000868- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
869 small GUI that lets you browse the module docstrings using your
870 default web browser.
871
Tim Peters1eff7962001-03-01 02:31:33 +0000872- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
873 Platforms) is implemented. See
874
875 http://python.sourceforge.net/peps/pep-0235.html
876
877 for full details, especially the "Current Lower-Left Semantics" section.
878 The new Windows import rules are simpler than before:
879
880 A. If the PYTHONCASEOK environment variable exists, same as
881 before: silently accept the first case-insensitive match of any
882 kind; raise ImportError if none found.
883
884 B. Else search sys.path for the first case-sensitive match; raise
885 ImportError if none found.
886
887 The same rules have been implented on other platforms with case-
888 insensitive but case-preserving filesystems too (including Cygwin, and
889 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000890
Tim Peters25a9ce32001-02-19 07:06:36 +0000891- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
892 what it's supposed to do (and does do under NT and 2000) via direct
893 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000894 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000895 all Win9x systems before.
896
Tim Peters1eff7962001-03-01 02:31:33 +0000897- Build: Subproject _test (effectively) renamed to _testcapi.
898
Tim Peters2fe289a2001-03-01 22:19:38 +0000899New platforms
900
901- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
902 Thanks to Steven Majewski!
903
904- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
905 Tishler!
906
Guido van Rossum9089b272001-03-02 06:49:50 +0000907- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
908 Schwertberger! See RISCOS/README for more information -- it seems
909 that because of the bizarre filename conventions on RISCOS, no port
910 to that platform is easy. Note that the new variable os.endsep is
911 silently supported in order to make life easier on this platform,
912 but we don't advertise it because it's not worth for most folks to
913 care about RISCOS portability.
914
Tim Peters25a9ce32001-02-19 07:06:36 +0000915
Tim Petersd7b5e882001-01-25 03:36:26 +0000916What's New in Python 2.1 alpha 2?
917=================================
Tim Peters40ead762001-01-27 05:35:26 +0000918
Tim Petersd7b5e882001-01-25 03:36:26 +0000919Core language, builtins, and interpreter
920
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000921- Scopes nest. If a name is used in a function or class, but is not
922 local, the definition in the nearest enclosing function scope will
923 be used. One consequence of this change is that lambda statements
924 could reference variables in the namespaces where the lambda is
925 defined. In some unusual cases, this change will break code.
926
927 In all previous version of Python, names were resolved in exactly
928 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000929 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000930 function A is defined within a function B, the names bound in B are
931 not visible in A. The new rules make names bound in B visible in A,
932 unless A contains a name binding that hides the binding in B.
933
934 Section 4.1 of the reference manual describes the new scoping rules
935 in detail. The test script in Lib/test/test_scope.py demonstrates
936 some of the effects of the change.
937
938 The new rules will cause existing code to break if it defines nested
939 functions where an outer function has local variables with the same
940 name as globals or builtins used by the inner function. Example:
941
942 def munge(str):
943 def helper(x):
944 return str(x)
945 if type(str) != type(''):
946 str = helper(str)
947 return str.strip()
948
949 Under the old rules, the name str in helper() is bound to the
950 builtin function str(). Under the new rules, it will be bound to
951 the argument named str and an error will occur when helper() is
952 called.
953
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000954- The compiler will report a SyntaxError if "from ... import *" occurs
955 in a function or class scope. The language reference has documented
956 that this case is illegal, but the compiler never checked for it.
957 The recent introduction of nested scope makes the meaning of this
958 form of name binding ambiguous. In a future release, the compiler
959 may allow this form when there is no possibility of ambiguity.
960
Tim Peters40ead762001-01-27 05:35:26 +0000961- repr(string) is easier to read, now using hex escapes instead of octal,
962 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
963
964 >>> "\texample \r\n" + chr(0) + chr(255)
965 '\texample \r\n\x00\xff' # in 2.1
966 '\011example \015\012\000\377' # in 2.0
967
Moshe Zadka6af0ce02001-01-29 06:41:00 +0000968- Functions are now compared and hashed by identity, not by value, since
969 the func_code attribute is writable.
970
Fred Drakefb9d7122001-02-01 20:00:40 +0000971- Weak references (PEP 205) have been added. This involves a few
972 changes in the core, an extension module (_weakref), and a Python
973 module (weakref). The weakref module is the public interface. It
974 includes support for "explicit" weak references, proxy objects, and
975 mappings with weakly held values.
976
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000977- A 'continue' statement can now appear in a try block within the body
978 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +0000979 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +0000980
Tim Petersd7b5e882001-01-25 03:36:26 +0000981Standard library
982
Barry Warsaw30dbd142001-01-31 22:14:01 +0000983- mailbox.py now has a new class, PortableUnixMailbox which is
984 identical to UnixMailbox but uses a more portable scheme for
985 determining From_ separators. Also, the constructors for all the
986 classes in this module have a new optional `factory' argument, which
987 is a callable used when new message classes must be instantiated by
988 the next() method.
989
Tim Petersd7b5e882001-01-25 03:36:26 +0000990- random.py is now self-contained, and offers all the functionality of
991 the now-deprecated whrandom.py. See the docs for details. random.py
992 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +0000993 and restoring the internal state of the generator; and jumpahead(n),
994 for quickly forcing the internal state to be the same as if n calls to
995 random() had been made. The latter is particularly useful for multi-
996 threaded programs, creating one instance of the random.Random() class for
997 each thread, then using .jumpahead() to force each instance to use a
998 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +0000999
Tim Peters0de88fc2001-02-01 04:59:18 +00001000- random.py's seed() function is new. For bit-for-bit compatibility with
1001 prior releases, use the whseed function instead. The new seed function
1002 addresses two problems: (1) The old function couldn't produce more than
1003 about 2**24 distinct internal states; the new one about 2**45 (the best
1004 that can be done in the Wichmann-Hill generator). (2) The old function
1005 sometimes produced identical internal states when passed distinct
1006 integers, and there was no simple way to predict when that would happen;
1007 the new one guarantees to produce distinct internal states for all
1008 arguments in [0, 27814431486576L).
1009
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001010- The socket module now supports raw packets on Linux. The socket
1011 family is AF_PACKET.
1012
Tim Peters9ea17ac2001-02-02 05:57:15 +00001013- test_capi.py is a start at running tests of the Python C API. The tests
1014 are implemented by the new Modules/_testmodule.c.
1015
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001016- A new extension module, _symtable, provides provisional access to the
1017 internal symbol table used by the Python compiler. A higher-level
1018 interface will be added on top of _symtable in a future release.
1019
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001020- Removed the obsolete soundex module.
1021
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001022- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1023 the isSameNode method; NamedNodeMap the get method.
1024
1025- xml.sax.expatreader supports the lexical handler property; it
1026 generates comment, startCDATA, and endCDATA events.
1027
Tim Petersee826f82001-01-31 19:39:44 +00001028Windows changes
1029
1030- Build procedure: the zlib project is built in a different way that
1031 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001032 the zlib binary used. See PCbuild\readme.txt for details. Your old
1033 zlib-related directories can be deleted; you'll need to download fresh
1034 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001035
Tim Peters9ea17ac2001-02-02 05:57:15 +00001036- Build: New subproject _test for the benefit of test_capi.py (see above).
1037
Tim Petersb16c56f2001-02-02 21:24:51 +00001038- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1039 interface to some Python compiler internals).
1040
1041- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001042 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001043
Tim Petersa3a3a032000-11-30 05:22:44 +00001044What's New in Python 2.1 alpha 1?
1045=================================
1046
1047Core language, builtins, and interpreter
1048
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001049- There is a new Unicode companion to the PyObject_Str() API
1050 called PyObject_Unicode(). It behaves in the same way as the
1051 former, but assures that the returned value is an Unicode object
1052 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001053
Guido van Rossumf98eda02001-01-17 15:54:45 +00001054- The comparison operators support "rich comparison overloading" (PEP
1055 207). C extension types can provide a rich comparison function in
1056 the new tp_richcompare slot in the type object. The cmp() function
1057 and the C function PyObject_Compare() first try the new rich
1058 comparison operators before trying the old 3-way comparison. There
1059 is also a new C API PyObject_RichCompare() (which also falls back on
1060 the old 3-way comparison, but does not constrain the outcome of the
1061 rich comparison to a Boolean result).
1062
1063 The rich comparison function takes two objects (at least one of
1064 which is guaranteed to have the type that provided the function) and
1065 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1066 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1067 object, which may be NotImplemented (in which case the tp_compare
1068 slot function is used as a fallback, if defined).
1069
1070 Classes can overload individual comparison operators by defining one
1071 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001072 __ge__. There are no explicit "reflected argument" versions of
1073 these; instead, __lt__ and __gt__ are each other's reflection,
1074 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1075 reflection (similar at the C level). No other implications are
1076 made; in particular, Python does not assume that == is the Boolean
1077 inverse of !=, or that < is the Boolean inverse of >=. This makes
1078 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001079
1080 Classes or types that want to implement (in)equality tests but not
1081 the ordering operators (i.e. unordered types) should implement ==
1082 and !=, and raise an error for the ordering operators.
1083
Guido van Rossuma88479f2001-01-18 14:28:08 +00001084 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001085 Boolean; e.g. a matrix type might want to return a matrix of bits
1086 for A < B, giving elementwise comparisons. Such types should ensure
1087 that any interpretation of their value in a Boolean context raises
1088 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1089 at the C level) to always raise an exception.
1090
Guido van Rossuma88479f2001-01-18 14:28:08 +00001091- Complex numbers use rich comparisons to define == and != but raise
1092 an exception for <, <=, > and >=. Unfortunately, this also means
1093 that cmp() of two complex numbers raises an exception when the two
1094 numbers differ. Since it is not mathematically meaningful to compare
1095 complex numbers except for equality, I hope that this doesn't break
1096 too much code.
1097
Tim Peters3389f192001-02-18 08:48:49 +00001098- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001099 not defined by the language, other than that it's arbitrary but
1100 consistent (see the Reference Manual). An implementation detail changed
1101 in 2.1a1 such that None now compares less than any other object. Code
1102 relying on this new behavior (like code that relied on the previous
1103 behavior) does so at its own risk.
1104
Barry Warsaw573b5412001-01-15 20:43:18 +00001105- Functions and methods now support getting and setting arbitrarily
1106 named attributes (PEP 232). Functions have a new __dict__
1107 (a.k.a. func_dict) which hold the function attributes. Methods get
1108 and set attributes on their underlying im_func. It is a TypeError
1109 to set an attribute on a bound method.
1110
Guido van Rossum051e3352001-01-15 19:11:10 +00001111- The xrange() object implementation has been improved so that
1112 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1113 limitation that in this case len(xrange(sys.maxint)) can't be
1114 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1115 work fine as long as the index i doesn't actually reach 2**31.
1116 (Python uses regular ints for sequence and string indices; fixing
1117 that is much more work.)
1118
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001119- Two changes to from...import:
1120
Guido van Rossumba381232001-02-03 15:06:40 +00001121 1) "from M import X" now works even if (after loading module M)
1122 sys.modules['M'] is not a real module; it's basically a getattr()
1123 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001124
1125 2) "from M import *" now looks for M.__all__ to decide which names to
1126 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1127 filters out names starting with '_' as before. Whether or not
1128 __all__ exists, there's no restriction on the type of M.
1129
Guido van Rossumf61f1662001-01-10 20:13:55 +00001130- File objects have a new method, xreadlines(). This is the fastest
1131 way to iterate over all lines in a file:
1132
1133 for line in file.xreadlines():
1134 ...do something to line...
1135
1136 See the xreadlines module (mentioned below) for how to do this for
1137 other file-like objects.
1138
1139- Even if you don't use file.xreadlines(), you may expect a speedup on
1140 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001141 quite a bit in platform-specific ways: on systems (like Linux) that
1142 support flockfile(), getc_unlocked(), and funlockfile(), those are
1143 used by default. On systems (like Windows) without getc_unlocked(),
1144 a complicated (but still thread-safe) method using fgets() is used by
1145 default.
1146
Tim Petersd52269b2001-01-25 06:23:18 +00001147 You can force use of the fgets() method by #define'ing
1148 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001149 getc_unlocked()).
1150
Tim Petersd52269b2001-01-25 06:23:18 +00001151 You can force fgets() not to be used by #define'ing
1152 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001153 test_bufio.py fails -- and let us know if it does!).
1154
1155- In addition, the fileinput module, while still slower than the other
1156 methods on most platforms, has been sped up too, by using
1157 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001158
1159- Support for run-time warnings has been added, including a new
1160 command line option (-W) to specify the disposition of warnings.
1161 See the description of the warnings module below.
1162
1163- Extensive changes have been made to the coercion code. This mostly
1164 affects extension modules (which can now implement mixed-type
1165 numerical operators without having to use coercion), but
1166 occasionally, in boundary cases the coercion semantics have changed
1167 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001168 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001169 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001170 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001171
Guido van Rossumf98eda02001-01-17 15:54:45 +00001172- In connection with the coercion changes, a new built-in singleton
1173 object, NotImplemented is defined. This can be returned for
1174 operations that wish to indicate they are not implemented for a
1175 particular combination of arguments. From C, this is
1176 Py_NotImplemented.
1177
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001178- The interpreter accepts now bytecode files on the command line even
1179 if they do not have a .pyc or .pyo extension. On Linux, after executing
1180
Martin v. Löwise214baa2001-02-04 22:37:56 +00001181import imp,sys,string
1182magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1183reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1184open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001185
1186 any byte code file can be used as an executable (i.e. as an argument
1187 to execve(2)).
1188
Tim Peters9940b802000-12-01 07:59:35 +00001189- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001190 character. In 1.6 and earlier, they never produced a sign,
1191 and raised an error if the value of the long was too large
1192 to fit in a Python int. In 2.0, they produced a sign if and
1193 only if too large to fit in an int. This was inconsistent
1194 across platforms (because the size of an int varies across
1195 platforms), and inconsistent with hex() and oct(). Example:
1196
1197 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001198 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001199 'ffffffbe' # in 2.0 and before, on 32-bit machines
1200 >>> hex(-0x42L)
1201 '-0x42L' # in all versions of Python
1202
Tim Peters9940b802000-12-01 07:59:35 +00001203 The behavior of %d formats for negative Python longs remains
1204 the same as in 2.0 (although in 1.6 and before, they raised
1205 an error if the long didn't fit in a Python int).
1206
1207 %u formats don't make sense for Python longs, but are allowed
1208 and treated the same as %d in 2.1. In 2.0, a negative long
1209 formatted via %u produced a sign if and only if too large to
1210 fit in an int. In 1.6 and earlier, a negative long formatted
1211 via %u raised an error if it was too big to fit in an int.
1212
Guido van Rossum3661d392000-12-12 22:10:31 +00001213- Dictionary objects have an odd new method, popitem(). This removes
1214 an arbitrary item from the dictionary and returns it (in the form of
1215 a (key, value) pair). This can be useful for algorithms that use a
1216 dictionary as a bag of "to do" items and repeatedly need to pick one
1217 item. Such algorithms normally end up running in quadratic time;
1218 using popitem() they can usually be made to run in linear time.
1219
Tim Peters36cdad12000-12-29 02:06:45 +00001220Standard library
1221
Thomas Woutersfe385252001-01-19 23:16:56 +00001222- In the time module, the time argument to the functions strftime,
1223 localtime, gmtime, asctime and ctime is now optional, defaulting to
1224 the current time (in the local timezone).
1225
Guido van Rossumda91f222001-01-15 16:36:08 +00001226- The ftplib module now defaults to passive mode, which is deemed a
1227 more useful default given that clients are often inside firewalls
1228 these days. Note that this could break if ftplib is used to connect
1229 to a *server* that is inside a firewall, from outside; this is
1230 expected to be a very rare situation. To fix that, you can call
1231 ftp.set_pasv(0).
1232
Martin v. Löwis10a27872001-01-13 09:54:41 +00001233- The module site now treats .pth files not only for path configuration,
1234 but also supports extensions to the initialization code: Lines starting
1235 with import are executed.
1236
Guido van Rossumf61f1662001-01-10 20:13:55 +00001237- There's a new module, warnings, which implements a mechanism for
1238 issuing and filtering warnings. There are some new built-in
1239 exceptions that serve as warning categories, and a new command line
1240 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1241 turns warnings into errors). warnings.warn(message[, category])
1242 issues a warning message; this can also be called from C as
1243 PyErr_Warn(category, message).
1244
1245- A new module xreadlines was added. This exports a single factory
1246 function, xreadlines(). The intention is that this code is the
1247 absolutely fastest way to iterate over all lines in an open
1248 file(-like) object:
1249
1250 import xreadlines
1251 for line in xreadlines.xreadlines(file):
1252 ...do something to line...
1253
1254 This is equivalent to the previous the speed record holder using
1255 file.readlines(sizehint). Note that if file is a real file object
1256 (as opposed to a file-like object), this is equivalent:
1257
1258 for line in file.xreadlines():
1259 ...do something to line...
1260
Tim Peters36cdad12000-12-29 02:06:45 +00001261- The bisect module has new functions bisect_left, insort_left,
1262 bisect_right and insort_right. The old names bisect and insort
1263 are now aliases for bisect_right and insort_right. XXX_right
1264 and XXX_left methods differ in what happens when the new element
1265 compares equal to one or more elements already in the list: the
1266 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001267 right. Code that doesn't care where equal elements end up should
1268 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001269
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001270- The new curses.panel module wraps the panel library that forms part
1271 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1272
Guido van Rossumf61f1662001-01-10 20:13:55 +00001273- The SocketServer module now sets the allow_reuse_address flag by
1274 default in the TCPServer class.
1275
1276- A new function, sys._getframe(), returns the stack frame pointer of
1277 the caller. This is intended only as a building block for
1278 higher-level mechanisms such as string interpolation.
1279
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001280- The pyexpat module supports a number of new handlers, which are
1281 available only in expat 1.2. If invocation of a callback fails, it
1282 will report an additional frame in the traceback. Parser objects
1283 participate now in garbage collection. If expat reports an unknown
1284 encoding, pyexpat will try to use a Python codec; that works only
1285 for single-byte charsets. The parser type objects is exposed as
1286 XMLParserObject.
1287
1288- xml.dom now offers standard definitions for symbolic node type and
1289 exception code constants, and a hierarchy of DOM exceptions. minidom
1290 was adjusted to use them.
1291
1292- The conformance of xml.dom.minidom to the DOM specification was
1293 improved. It detects a number of additional error cases; the
1294 previous/next relationship works even when the tree is modified;
1295 Node supports the normalize() method; NamedNodeMap, DocumentType and
1296 DOMImplementation classes were added; Element supports the
1297 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1298 method.
1299
Guido van Rossumf61f1662001-01-10 20:13:55 +00001300Build issues
1301
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001302- For Unix (and Unix-compatible) builds, configuration and building of
1303 extension modules is now greatly automated. Rather than having to
1304 edit the Modules/Setup file to indicate which modules should be
1305 built and where their include files and libraries are, a
1306 distutils-based setup.py script now takes care of building most
1307 extension modules. All extension modules built this way are built
1308 as shared libraries. Only a few modules that must be linked
1309 statically are still listed in the Setup file; you won't need to
1310 edit their configuration.
1311
1312- Python should now build out of the box on Cygwin. If it doesn't,
1313 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001314
1315- Python now always uses its own (renamed) implementation of getopt()
1316 -- there's too much variation among C library getopt()
1317 implementations.
1318
1319- C++ compilers are better supported; the CXX macro is always set to a
1320 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001321
Tim Petersd92dfe02000-12-12 01:18:41 +00001322Windows changes
1323
1324- select module: By default under Windows, a select() call
1325 can specify no more than 64 sockets. Python now boosts
1326 this Microsoft default to 512. If you need even more than
1327 that, see the MS docs (you'll need to #define FD_SETSIZE
1328 and recompile Python from source).
1329
Guido van Rossumf61f1662001-01-10 20:13:55 +00001330- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1331 subdirectory is no more!
1332
Tim Petersa3a3a032000-11-30 05:22:44 +00001333
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001334What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001335=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001336
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001337Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001338changes are in the file HISTORY. If you are making the jump directly
1339from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1340HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001341
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001342Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1343the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1344http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001345
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001346--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001347
1348======================================================================
1349
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001350What's new in 2.0 (since release candidate 1)?
1351==============================================
1352
1353Standard library
1354
1355- The copy_reg module was modified to clarify its intended use: to
1356 register pickle support for extension types, not for classes.
1357 pickle() will raise a TypeError if it is passed a class.
1358
1359- Fixed a bug in gettext's "normalize and expand" code that prevented
1360 it from finding an existing .mo file.
1361
1362- Restored support for HTTP/0.9 servers in httplib.
1363
Tim Peters989b7b92000-10-16 20:24:53 +00001364- The math module was changed to stop raising OverflowError in case of
1365 underflow, and return 0 instead in underflow cases. Whether Python
1366 used to raise OverflowError in case of underflow was platform-
1367 dependent (it did when the platform math library set errno to ERANGE
1368 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001369
1370- Fixed a bug in StringIO that occurred when the file position was not
1371 at the end of the file and write() was called with enough data to
1372 extend past the end of the file.
1373
1374- Fixed a bug that caused Tkinter error messages to get lost on
1375 Windows. The bug was fixed by replacing direct use of
1376 interp->result with Tcl_GetStringResult(interp).
1377
1378- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1379 redirect response.
1380
1381- Several changes were made to distutils: Some debugging code was
1382 removed from util. Fixed the installer used when an external zip
1383 program (like WinZip) is not found; the source code for this
1384 installer is in Misc/distutils. check_lib() was modified to behave
1385 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1386 test for whether installed modules are on sys.path was changed to
1387 use both normcase() and normpath().
1388
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001389- Several minor bugs were fixed in the xml package (the minidom,
1390 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001391
1392- The regression test driver (regrtest.py) behavior when invoked with
1393 -l changed: It now reports a count of objects that are recognized as
1394 garbage but not freed by the garbage collector.
1395
Tim Peters989b7b92000-10-16 20:24:53 +00001396- The regression test for the math module was changed to test
1397 exceptional behavior when the test is run in verbose mode. Python
1398 cannot yet guarantee consistent exception behavior across platforms,
1399 so the exception part of test_math is run only in verbose mode, and
1400 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001401
1402Internals
1403
1404- PyOS_CheckStack() has been disabled on Win64, where it caused
1405 test_sre to fail.
1406
1407Build issues
1408
1409- Changed compiler flags, so that gcc is always invoked with -Wall and
1410 -Wstrict-prototypes. Users compiling Python with GCC should see
1411 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001412 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001413 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001414
Tim Petersa3a3a032000-11-30 05:22:44 +00001415- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001416
1417Tools and other miscellany
1418
1419- The compiler in Tools/compiler was updated to support the new
1420 language features introduced in 2.0: extended print statement, list
1421 comprehensions, and augmented assignments. The new compiler should
1422 also be backwards compatible with Python 1.5.2; the compiler will
1423 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001424 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001425
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001426What's new in 2.0 release candidate 1 (since beta 2)?
1427=====================================================
1428
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001429What is release candidate 1?
1430
1431We believe that release candidate 1 will fix all known bugs that we
1432intend to fix for the 2.0 final release. This release should be a bit
1433more stable than the previous betas. We would like to see even more
1434widespread testing before the final release, so we are producing this
1435release candidate. The final release will be exactly the same unless
1436any show-stopping (or brown bag) bugs are found by testers of the
1437release candidate.
1438
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001439All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001440to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001441
1442Core language, builtins, and interpreter
1443
1444- A bug that caused crashes when __coerce__ was used with augmented
1445 assignment, e.g. +=, was fixed.
1446
1447- Raise ZeroDivisionError when raising zero to a negative number,
1448 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1449 power operator and the result of math.pow(0.0, -2.0) will vary by
1450 platform. On Linux, it raises a ValueError.
1451
1452- A bug in Unicode string interpolation was fixed that occasionally
1453 caused errors with formats including "%%". For example, the
1454 following expression "%% %s" % u"abc" no longer raises a TypeError.
1455
1456- Compilation of deeply nested expressions raises MemoryError instead
1457 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1458
1459- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1460 rendering them useless. They are now written in binary mode again.
1461
1462Standard library
1463
1464- Keyword arguments are now accepted for most pattern and match object
1465 methods in SRE, the standard regular expression engine.
1466
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001467- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001468 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001469
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001470- Several bugs in the Unicode handling and error handling in _tkinter
1471 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001472
1473- Fix memory management errors in Merge() and Tkapp_Call() routines.
1474
1475- Several changes were made to cStringIO to make it compatible with
1476 the file-like object interface and with StringIO. If operations are
1477 performed on a closed object, an exception is raised. The truncate
1478 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001479 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001480
1481- There were many changes made to the linuxaudiodev module and its
1482 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001483 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001484
1485 Note that this module is named poorly, because it should work
1486 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001487 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001488
1489 The module now raises exceptions when errors occur instead of
1490 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1491 audio) and defines a getptr() method that calls the
1492 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1493
1494- The library_version attribute, introduced in an earlier beta, was
1495 removed because it can not be supported with early versions of the C
1496 readline library, which provides no way to determine the version at
1497 compile-time.
1498
1499- The binascii module is now enabled on Win64.
1500
Tim Peters46446d62000-10-09 21:19:31 +00001501- tokenize.py no longer suffers "recursion depth" errors when parsing
1502 programs with very long string literals.
1503
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001504Internals
1505
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001506- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001507 which is called when the interpreter starts up to determine where
1508 the standard library is installed. These vulnerabilities affect all
1509 previous versions of Python and can be exploited by setting very
1510 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1511 setuid Python script, although use of the wrapper in
1512 Misc/setuid-prog.c will eliminate the vulnerability.
1513
1514- Fixed garbage collection bugs in instance creation that were
1515 triggered when errors occurred during initialization. The solution,
1516 applied in cPickle and in PyInstance_New(), is to call
1517 PyObject_GC_Init() after the initialization of the object's
1518 container attributes is complete.
1519
1520- pyexpat adds definitions of PyModule_AddStringConstant and
1521 PyModule_AddObject if the Python version is less than 2.0, which
1522 provides compatibility with PyXML on Python 1.5.2.
1523
1524- If the platform has a bogus definition for LONG_BIT (the number of
1525 bits in a long), an error will be reported at compile time.
1526
1527- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1528 collection crashes and possibly other, unreported crashes.
1529
1530- Fixed a memory leak in _PyUnicode_Fini().
1531
1532Build issues
1533
1534- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001535 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001536 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001537
1538- The mmap.PAGESIZE constant is now initialized using sysconf when
1539 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1540
1541- The md5 file should now compile on all platforms.
1542
1543- The select module now compiles on platforms that do not define
1544 POLLRDNORM and related constants.
1545
1546- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001547 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001548
Jeremy Hylton10921202000-10-09 18:34:12 +00001549- BeOS: A number of changes were made to the build and installation
1550 process. ar-fake now operates on a directory of object files.
1551 dl_export.h is gone, and its macros now appear on the mwcc command
1552 line during build on PPC BeOS.
1553
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001554- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001555 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001556
1557- Cygwin: Support for shared libraries, Tkinter, and sockets.
1558
1559- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1560
1561Tools and other miscellany
1562
1563- Removed debugging prints from main used with freeze.
1564
Tim Peters46446d62000-10-09 21:19:31 +00001565- IDLE auto-indent no longer crashes when it encounters Unicode
1566 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001567
1568What's new in 2.0 beta 2 (since beta 1)?
1569========================================
1570
1571Core language, builtins, and interpreter
1572
Tim Peters482c0212000-09-26 06:33:09 +00001573- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001574 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001575
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001576- Add -h and -V command line options to print the usage message and
1577 Python version number and exit immediately.
1578
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001579- eval() and exec accept Unicode objects as code parameters.
1580
1581- getattr() and setattr() now also accept Unicode objects for the
1582 attribute name, which are converted to strings using the default
1583 encoding before lookup.
1584
1585- Multiplication on string and Unicode now does proper bounds
1586 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1587 string is too long."
1588
1589- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001590 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001591
Jeremy Hylton1b618592000-09-26 05:32:36 +00001592
1593Standard library and extensions
1594
Guido van Rossum5b08f132001-04-16 02:05:23 +00001595- socket module: the OpenSSL code now adds support for RAND_status()
1596 and EGD (Entropy Gathering Device).
1597
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001598- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001599 argument checking; it still takes no arguments.
1600
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001601- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001602
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001603- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001604
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001605- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001606
1607- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001608 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001609
1610- copy: Copy Unicode objects atomically.
1611
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001612- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001613
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001614- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001615
Fred Drake67233bc2000-09-26 16:40:27 +00001616- dbm: Add get() and setdefault() methods to dbm object. Add constant
1617 `library' to module that names the library used. Added doc strings
1618 and method names to error messages. Uses configure to determine
1619 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1620 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001621
1622- distutils: Update to version 0.9.3.
1623
1624- dl: Add several dl.RTLD_ constants.
1625
1626- fpectl: Now supported on FreeBSD.
1627
1628- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1629 found by the collector will be saved in gc.garbage. This is useful
1630 for debugging a program that creates reference cycles.
1631
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001632- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001633 of HTTP class. Do not close socket on zero-length response. Do not
1634 crash when server sends invalid content-length header.
1635
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001636- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001637
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001638- marshal: When reading a short, sign-extend on platforms where shorts
1639 are bigger than 16 bits. When reading a long, repair the unportable
1640 sign extension that was being done for 64-bit machines. (It assumed
1641 that signed right shift sign-extends.)
1642
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001643- operator: Add contains(), invert(), __invert__() as aliases for
1644 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001645
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001646- os: Add support for popen2() and popen3() on all platforms where
1647 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001648
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001649- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001650 clicking on a file in Explorer (or passing the file name to the
1651 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001652
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001653- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001654 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001655
1656- pickle: Now raises ValueError when an invalid pickle that contains
1657 a non-string repr where a string repr was expected. This behavior
1658 matches cPickle.
1659
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001660- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001661
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001662- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001663
1664- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001665 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001666 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001667
1668- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001669 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001670
1671- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001672 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001673 few cycles during startup since the first call to
1674 setdefaultencoding() will initialize the codec registry and the
1675 encodings package.
1676
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001677- socket: Support for size hint in readlines() method of object returned
1678 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001679
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001680- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001681 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001682 is followed by whitespace.
1683
Tim Petersa3a3a032000-11-30 05:22:44 +00001684- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001685
1686- struct: Check ranges for bytes and shorts.
1687
1688- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001689 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001690
1691- Tkinter: Image objects are now guaranteed to have unique ids. Set
1692 event.delta to zero if Tk version doesn't support mousewheel.
1693 Removed some debugging prints.
1694
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001695- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001696
Fred Drake67233bc2000-09-26 16:40:27 +00001697- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001698 which works around a bug in Norton AntiVirus 2000 that leads directly
1699 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001700
1701- xml: New version detection code allows PyXML to override standard
1702 XML package if PyXML version is greater than 0.6.1.
1703
Fred Drake64bb3802000-09-26 16:21:35 +00001704- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1705 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1706 tree only for nodes which are sufficiently interesting to a specific
1707 application. Does not provide the HTML-specific extensions. Still
1708 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001709
Fred Drake64bb3802000-09-26 16:21:35 +00001710- xml.sax: SAX 2 support for Python, including all the handler
1711 interfaces needed to process XML 1.0 compliant XML. Some
1712 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001713
Fred Drake64bb3802000-09-26 16:21:35 +00001714- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1715 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001716
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001717
Jeremy Hylton1b618592000-09-26 05:32:36 +00001718C API
1719
1720- Add three new convenience functions for module initialization --
1721 PyModule_AddObject(), PyModule_AddIntConstant(), and
1722 PyModule_AddStringConstant().
1723
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001724- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001725 removed and add #error to Python.h if NULL isn't defined after
1726 #include of stdio.h.
1727
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001728- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001729 backwards compatibility (at the source level) with old extensions.
1730
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001731- A wrapper API was added for signal() and sigaction(). Instead of
1732 either function, always use PyOS_getsig() to get a signal handler
1733 and PyOS_setsig() to set one. A new convenience typedef
1734 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001735
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001736- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001737 internal data buffer and size of a string object -- or the default
1738 encoded version of a Unicode object.
1739
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001740- PyString_Size() and PyString_AsString() accept Unicode objects.
1741
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001742- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001743 exists). INT_MAX and LONG_MAX will always be defined, even if
1744 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001745
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001746- PyFloat_FromString takes a second argument, pend, that was
1747 effectively useless. It is now officially useless but preserved for
1748 backwards compatibility. If the pend argument is not NULL, *pend is
1749 set to NULL.
1750
1751- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1752 for the attribute name. See note on getattr() above.
1753
1754- A few bug fixes to argument processing for Unicode.
1755 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1756 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1757 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001758 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001759
1760- Py_BuildValue accepts B format (for bgen-generated code).
1761
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001762
Jeremy Hylton1b618592000-09-26 05:32:36 +00001763Internals
1764
1765- On Unix, fix code for finding Python installation directory so that
1766 it works when argv[0] is a relative path.
1767
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001768- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001769 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001770 rather than by generating a copy of the object.
1771
Tim Peters482c0212000-09-26 06:33:09 +00001772- Several of the internal Unicode tables are much smaller now, and
1773 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001774
Jeremy Hylton97693b02000-09-26 17:42:51 +00001775- In the garbage collector: Fixed bug in collection of tuples. Fixed
1776 bug that caused some instances to be removed from the container set
1777 while they were still live. Fixed parsing in gc.set_debug() for
1778 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001779
1780- Fixed refcount problem in instance deallocation that only occurred
1781 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1782
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001783- On Windows, getpythonregpath is now protected against null data in
1784 registry key.
1785
1786- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001787 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001788
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001789
Jeremy Hylton1b618592000-09-26 05:32:36 +00001790Build and platform-specific issues
1791
1792- Better support of GNU Pth via --with-pth configure option.
1793
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001794- Python/C API now properly exposed to dynamically-loaded extension
1795 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001796
1797- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1798 Don't define MS_SYNC to be zero when it is undefined. Added missing
1799 prototypes in posixmodule.c.
1800
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001801- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001802 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001803
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001804- Fix largefile support on older NetBSD systems and OpenBSD by adding
1805 define for TELL64.
1806
1807
1808Tools and other miscellany
1809
1810- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1811
1812- freeze: The modulefinder now works with 2.0 opcodes.
1813
Tim Petersa3a3a032000-11-30 05:22:44 +00001814- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001815 Move hackery of sys.argv until after the Tk instance has been
1816 created, which allows the application-specific Tkinter
1817 initialization to be executed if present; also pass an explicit
1818 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001819
Jeremy Hylton1b618592000-09-26 05:32:36 +00001820
1821What's new in 2.0 beta 1?
1822=========================
1823
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001824Source Incompatibilities
1825------------------------
1826
1827None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1828such as single-argument append(), connect() and bind(), and changes to
1829str(long) and repr(float).
1830
1831
1832Binary Incompatibilities
1833------------------------
1834
1835- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1836with Python 2.0; these extensions will have to be rebuilt for Python
18372.0.
1838
1839- On Windows, attempting to import a third party extension built for
1840Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1841can do about this. Check your PYTHONPATH environment variable!
1842
1843- Python bytecode files (*.pyc and *.pyo) are not compatible between
1844releases.
1845
1846
1847Overview of Changes Since 1.6
1848-----------------------------
1849
1850There are many new modules (including brand new XML support through
1851the xml package, and i18n support through the gettext module); a list
1852of all new modules is included below. Lots of bugs have been fixed.
1853
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001854The process for making major new changes to the language has changed
1855since Python 1.6. Enhancements must now be documented by a Python
1856Enhancement Proposal (PEP) before they can be accepted.
1857
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001858There are several important syntax enhancements, described in more
1859detail below:
1860
1861 - Augmented assignment, e.g. x += 1
1862
1863 - List comprehensions, e.g. [x**2 for x in range(10)]
1864
1865 - Extended import statement, e.g. import Module as Name
1866
1867 - Extended print statement, e.g. print >> file, "Hello"
1868
1869Other important changes:
1870
1871 - Optional collection of cyclical garbage
1872
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001873Python Enhancement Proposal (PEP)
1874---------------------------------
1875
1876PEP stands for Python Enhancement Proposal. A PEP is a design
1877document providing information to the Python community, or describing
1878a new feature for Python. The PEP should provide a concise technical
1879specification of the feature and a rationale for the feature.
1880
1881We intend PEPs to be the primary mechanisms for proposing new
1882features, for collecting community input on an issue, and for
1883documenting the design decisions that have gone into Python. The PEP
1884author is responsible for building consensus within the community and
1885documenting dissenting opinions.
1886
1887The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001888
1889Augmented Assignment
1890--------------------
1891
1892This must have been the most-requested feature of the past years!
1893Eleven new assignment operators were added:
1894
Guido van Rossume905e952000-09-05 12:42:46 +00001895 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001896
1897For example,
1898
1899 A += B
1900
1901is similar to
1902
1903 A = A + B
1904
1905except that A is evaluated only once (relevant when A is something
1906like dict[index].attr).
1907
1908However, if A is a mutable object, A may be modified in place. Thus,
1909if A is a number or a string, A += B has the same effect as A = A+B
1910(except A is only evaluated once); but if a is a list, A += B has the
1911same effect as A.extend(B)!
1912
1913Classes and built-in object types can override the new operators in
1914order to implement the in-place behavior; the not-in-place behavior is
1915used automatically as a fallback when an object doesn't implement the
1916in-place behavior. For classes, the method name is derived from the
1917method name for the corresponding not-in-place operator by inserting
1918an 'i' in front of the name, e.g. __iadd__ implements in-place
1919__add__.
1920
1921Augmented assignment was implemented by Thomas Wouters.
1922
1923
1924List Comprehensions
1925-------------------
1926
1927This is a flexible new notation for lists whose elements are computed
1928from another list (or lists). The simplest form is:
1929
1930 [<expression> for <variable> in <sequence>]
1931
Guido van Rossum56db0952000-09-06 23:34:25 +00001932For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001933This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001934
1935You can also add a condition:
1936
1937 [<expression> for <variable> in <sequence> if <condition>]
1938
1939For example, [w for w in words if w == w.lower()] would yield the list
1940of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001941than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001942
1943You can also have nested for loops and more than one 'if' clause. For
1944example, here's a function that flattens a sequence of sequences::
1945
1946 def flatten(seq):
1947 return [x for subseq in seq for x in subseq]
1948
1949 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
1950
1951This prints
1952
1953 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
1954
1955List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001956Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001957
1958
1959Extended Import Statement
1960-------------------------
1961
1962Many people have asked for a way to import a module under a different
1963name. This can be accomplished like this:
1964
1965 import foo
1966 bar = foo
1967 del foo
1968
1969but this common idiom gets old quickly. A simple extension of the
1970import statement now allows this to be written as follows:
1971
1972 import foo as bar
1973
1974There's also a variant for 'from ... import':
1975
1976 from foo import bar as spam
1977
1978This also works with packages; e.g. you can write this:
1979
1980 import test.regrtest as regrtest
1981
1982Note that 'as' is not a new keyword -- it is recognized only in this
1983context (this is only possible because the syntax for the import
1984statement doesn't involve expressions).
1985
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001986Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001987
1988
1989Extended Print Statement
1990------------------------
1991
1992Easily the most controversial new feature, this extension to the print
1993statement adds an option to make the output go to a different file
1994than the default sys.stdout.
1995
1996For example, to write an error message to sys.stderr, you can now
1997write:
1998
1999 print >> sys.stderr, "Error: bad dog!"
2000
2001As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002002evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002003
2004 print >> None, "Hello world"
2005
2006is equivalent to
2007
2008 print "Hello world"
2009
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002010Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002011
2012
2013Optional Collection of Cyclical Garbage
2014---------------------------------------
2015
2016Python is now equipped with a garbage collector that can hunt down
2017cyclical references between Python objects. It's no replacement for
2018reference counting; in fact, it depends on the reference counts being
2019correct, and decides that a set of objects belong to a cycle if all
2020their reference counts can be accounted for from their references to
2021each other. This devious scheme was first proposed by Eric Tiedemann,
2022and brought to implementation by Neil Schemenauer.
2023
2024There's a module "gc" that lets you control some parameters of the
2025garbage collection. There's also an option to the configure script
2026that lets you enable or disable the garbage collection. In 2.0b1,
2027it's on by default, so that we (hopefully) can collect decent user
2028experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002029performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002030off by default in the final 2.0 release.
2031
2032
2033Smaller Changes
2034---------------
2035
2036A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2037map(None, seq1, seq2, ...) when the sequences have the same length;
2038i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2039the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002040zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002041
2042sys.version_info is a tuple (major, minor, micro, level, serial).
2043
2044Dictionaries have an odd new method, setdefault(key, default).
2045dict.setdefault(key, default) returns dict[key] if it exists; if not,
2046it sets dict[key] to default and returns that value. Thus:
2047
2048 dict.setdefault(key, []).append(item)
2049
2050does the same work as this common idiom:
2051
2052 if not dict.has_key(key):
2053 dict[key] = []
2054 dict[key].append(item)
2055
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002056There are two new variants of SyntaxError that are raised for
2057indentation-related errors: IndentationError and TabError.
2058
2059Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2060escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002061
2062The limits on the size of expressions and file in Python source code
2063have been raised from 2**16 to 2**32. Previous versions of Python
2064were limited because the maximum argument size the Python VM accepted
2065was 2**16. This limited the size of object constructor expressions,
2066e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2067limit was raised thanks to a patch by Charles Waldman that effectively
2068fixes the problem. It is now much more likely that you will be
2069limited by available memory than by an arbitrary limit in Python.
2070
2071The interpreter's maximum recursion depth can be modified by Python
2072programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2073limit is the maximum number of recursive calls that can be made by
2074Python code. The limit exists to prevent infinite recursion from
2075overflowing the C stack and causing a core dump. The default value is
20761000. The maximum safe value for a particular platform can be found
2077by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002078
2079New Modules and Packages
2080------------------------
2081
2082atexit - for registering functions to be called when Python exits.
2083
2084imputil - Greg Stein's alternative API for writing custom import
2085hooks.
2086
2087pyexpat - an interface to the Expat XML parser, contributed by Paul
2088Prescod.
2089
2090xml - a new package with XML support code organized (so far) in three
2091subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2092would fill a volume. There's a special feature whereby a
2093user-installed package named _xmlplus overrides the standard
2094xmlpackage; this is intended to give the XML SIG a hook to distribute
2095backwards-compatible updates to the standard xml package.
2096
2097webbrowser - a platform-independent API to launch a web browser.
2098
2099
Guido van Rossume905e952000-09-05 12:42:46 +00002100Changed Modules
2101---------------
2102
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002103array -- new methods for array objects: count, extend, index, pop, and
2104remove
2105
2106binascii -- new functions b2a_hex and a2b_hex that convert between
2107binary data and its hex representation
2108
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002109calendar -- Many new functions that support features including control
2110over which day of the week is the first day, returning strings instead
2111of printing them. Also new symbolic constants for days of week,
2112e.g. MONDAY, ..., SUNDAY.
2113
2114cgi -- FieldStorage objects have a getvalue method that works like a
2115dictionary's get method and returns the value attribute of the object.
2116
2117ConfigParser -- The parser object has new methods has_option,
2118remove_section, remove_option, set, and write. They allow the module
2119to be used for writing config files as well as reading them.
2120
2121ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002122optionally support the RFC 959 REST command.
2123
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002124gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002125
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002126httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2127the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002128
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002129locale -- implement getdefaultlocale for Win32 and Macintosh
2130
2131marshal -- no longer dumps core when marshaling deeply nested or
2132recursive data structures
2133
2134os -- new functions isatty, seteuid, setegid, setreuid, setregid
2135
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002136os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2137support under Unix.
2138
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002139os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002140
2141os.path -- fix semantics of os.path.commonprefix
2142
2143smtplib -- support for sending very long messages
2144
2145socket -- new function getfqdn()
2146
2147readline -- new functions to read, write and truncate history files.
2148The readline section of the library reference manual contains an
2149example.
2150
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002151select -- add interface to poll system call
2152
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002153shutil -- new copyfileobj function
2154
2155SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2156HTTP server.
2157
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002158Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002159
2160urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002161e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002162
2163whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002164
2165
2166Obsolete Modules
2167----------------
2168
2169None. However note that 1.6 made a whole slew of modules obsolete:
2170stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2171poly, zmod, strop, util, whatsound.
2172
2173
2174Changed, New, Obsolete Tools
2175----------------------------
2176
Tim Peters8b092332000-09-05 20:15:25 +00002177None.
Guido van Rossume905e952000-09-05 12:42:46 +00002178
2179
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002180C-level Changes
2181---------------
2182
2183Several cleanup jobs were carried out throughout the source code.
2184
2185All C code was converted to ANSI C; we got rid of all uses of the
2186Py_PROTO() macro, which makes the header files a lot more readable.
2187
2188Most of the portability hacks were moved to a new header file,
2189pyport.h; several other new header files were added and some old
2190header files were removed, in an attempt to create a more rational set
2191of header files. (Few of these ever need to be included explicitly;
2192they are all included by Python.h.)
2193
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002194Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002195and Win64, especially for the new Intel Itanium processor. Mick also
2196added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002197
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002198The C APIs to return an object's size have been update to consistently
2199use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2200previous versions, the abstract interfaces used PyXXX_Length and the
2201concrete interfaces used PyXXX_Size. The old names,
2202e.g. PyObject_Length, are still available for backwards compatibility
2203at the API level, but are deprecated.
2204
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002205The PyOS_CheckStack function has been implemented on Windows by
2206Fredrik Lundh. It prevents Python from failing with a stack overflow
2207on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002208
2209The GC changes resulted in creation of two new slots on object,
2210tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002211the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002212
2213The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002214C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002215
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002216PyErr_Format has been updated to automatically calculate the size of
2217the buffer needed to hold the formatted result string. This change
2218prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002219
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002220New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002221
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002222PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2223that are the same as their non-Ex counterparts except they take an
2224extra flag argument that tells them to close the file when done.
2225
2226XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002227
Tim Peters8b092332000-09-05 20:15:25 +00002228
2229Windows Changes
2230---------------
2231
2232New popen2/popen3/peopen4 in os module (see Changed Modules above).
2233
2234os.popen is much more usable on Windows 95 and 98. See Microsoft
2235Knowledge Base article Q150956. The Win9x workaround described there
2236is implemented by the new w9xpopen.exe helper in the root of your
2237Python installation. Note that Python uses this internally; it is not
2238a standalone program.
2239
2240Administrator privileges are no longer required to install Python
2241on Windows NT or Windows 2000. If you have administrator privileges,
2242Python's registry info will be written under HKEY_LOCAL_MACHINE.
2243Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002244under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002245uses of Python, but will prevent some advanced uses from working
2246(for example, running a Python script as an NT service, or possibly
2247from CGI).
2248
2249[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2250installer; instead, it installs the needed Tcl/Tk files directly in the
2251Python directory. If you already have a Tcl/Tk installation, this
2252wastes some disk space (about 4 Megs) but avoids problems with
2253conflicting Tcl/Tk installations, and makes it much easier for Python
2254to ensure that Tcl/Tk can find all its files.
2255
2256[This was new in 1.6] The Windows installer now installs by default in
2257\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2258
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002259
2260Updates to the changes between 1.5.2 and 1.6
2261--------------------------------------------
2262
2263The 1.6 NEWS file can't be changed after the release is done, so here
2264is some late-breaking news:
2265
2266New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2267and changes to getlocale() and setlocale().
2268
2269The new module is now enabled per default.
2270
2271It is not true that the encodings codecs cannot be used for normal
2272strings: the string.encode() (which is also present on 8-bit strings
2273!) allows using them for 8-bit strings too, e.g. to convert files from
2274cp1252 (Windows) to latin-1 or vice-versa.
2275
2276Japanese codecs are available from Tamito KAJIYAMA:
2277http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2278
2279
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002280======================================================================