blob: 2d27de86e5e6cd2d5a9d42c063423b667b9692ad [file] [log] [blame]
Tim Petersedc99312001-08-22 21:36:50 +00001What's New in Python 2.2a3?
2===========================
3
4Core
5
Tim Peters9fffa3e2001-09-04 05:14:19 +00006- Conversion of long to float now raises OverflowError if the long is too
7 big to represent as a C double.
8
Tim Peters32f453e2001-09-03 08:35:41 +00009- The 3-argument builtin pow() no longer allows a third non-None argument
10 if either of the first two arguments is a float, or if both are of
11 integer types and the second argument is negative (in which latter case
12 the arguments are converted to float, so this is really the same
13 restriction).
14
Tim Peters5d2b77c2001-09-03 05:47:38 +000015- The builtin dir() now returns more information, and sometimes much
16 more, generally naming all attributes of an object, and all attributes
17 reachable from the object via its class, and from its class's base
18 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
19 an empty list. In 2.2a3,
20
21 >>> dir([])
22 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
23 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
24 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
25 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
26 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
27 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
28 'reverse', 'sort']
29
30 dir(module) continues to return only the module's attributes, though.
31
Tim Petersbdee63f2001-09-02 03:40:59 +000032- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +000033 than raising OverflowError. This is a partial implementation of PEP
34 237. You can use -Wdefault::OverflowWarning to enable a warning for
35 this situation, and -Werror::OverflowWarning to revert to the old
36 OverflowError exception.
37
Guido van Rossum61c345f2001-09-04 03:26:15 +000038- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +000039 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +000040 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
41 -Qold, meaning the / operator has its classic meaning and no
42 warnings are issued. Using -Qwarn issues a run-time warning about
43 all uses of classic division for int and long arguments; -Qwarnall
44 also warns about classic division for float and complex arguments
45 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
46 new division by default, but only in the __main__ module. You can
47 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
48 __main__ module new division, and warns about classic division
49 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +000050
Tim Petersbdee63f2001-09-02 03:40:59 +000051- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +000052 long, float, str, unicode, and tuple. (The types complex, list and
53 dictionary can also be subclassed; this was introduced earlier.)
54 Note that restrictions apply when subclassing immutable built-in
55 types: you can only affect the value of the instance by overloading
56 __new__. You can add mutable attributes, and the subclass instances
57 will have a __dict__ attribute, but you cannot change the "value"
58 (as implemented by the base class) of an immutable subclass instance
59 once it is created.
60
Guido van Rossumaaf80c82001-09-02 13:44:35 +000061- The dictionary constructor now takes an optional argument, a
62 mapping-like object, and initializes the dictionary from its
63 (key, value) pairs.
64
Tim Petersbdee63f2001-09-02 03:40:59 +000065- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +000066 "cooperative super calls" in a multiple inheritance setting. For an
67 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
68
Guido van Rossum8d7234d2001-09-06 22:02:58 +000069- A new built-in type, property, has been added. This enables the
70 creation of "properties". These are attributes implemented by
71 getter and setter functions (or only one of these for read-only or
72 write-only attributes), without the need to override __getattr__.
73 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +000074
Tim Petersbdee63f2001-09-02 03:40:59 +000075- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +000076 liberalized, to allow leading zeroes. Examples of literals now
77 legal that were SyntaxErrors before:
78
79 00.0 0e3 0100j 07.5 00000000000000000008.
80
Tim Petersbdee63f2001-09-02 03:40:59 +000081- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +000082 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
83
Tim Petersedc99312001-08-22 21:36:50 +000084Library
85
Martin v. Löwiscb227c92001-09-06 08:54:16 +000086- telnetlib includes symbolic names for the options, and support for
87 setting an option negotiation callback.
88
Tim Petersa40c7932001-09-05 22:36:56 +000089- The new C standard no longer requires that math libraries set errno to
90 ERANGE on overflow. For platform libraries that exploit this new
91 freedom, Python's overflow-checking was wholly broken. A new overflow-
92 checking scheme attempts to repair that, but may not be reliable on all
93 platforms (C doesn't seem to provide anything both useful and portable
94 in this area anymore).
95
Martin v. Löwis44f86962001-09-05 13:44:54 +000096- Asynchronous timeout actions are available through the new class
97 threading.Timer.
98
Tim Peters78526162001-09-05 00:53:45 +000099- math.log and math.log10 now return sensible results for even huge
100 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
101
Tim Petersbdee63f2001-09-02 03:40:59 +0000102- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000103 currently held. See the docs for the imp module.
104
Tim Petersbdee63f2001-09-02 03:40:59 +0000105- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000106 dumps containing ints written on platforms where Python ints are 8 bytes.
107 When read on a box where Python ints are 4 bytes, such values are
108 converted to Python longs.
109
Tim Petersbdee63f2001-09-02 03:40:59 +0000110- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000111 code objects is no longer allowed. This plugs a security hole.
112
Steve Purcell6091cd62001-09-06 16:05:17 +0000113- unittest.TestResult instances no longer store references to tracebacks
114 generated by test failures. This prevents unexpected dangling references
115 to objects that should be garbage collected between tests.
116
Tim Petersedc99312001-08-22 21:36:50 +0000117Tools
118
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000119- Tools/scripts/fixdiv.py has been added which can be used to fix
120 division operators as per PEP 238.
121
Tim Petersedc99312001-08-22 21:36:50 +0000122Build
123
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000124- If you are an adventurous person using Mac OS X you may want to look at
125 Mac/OSX. There is a Makefile there that will build Python as a real Mac
126 application, which can be used for experimenting with Carbon or Cocoa.
127 Discussion of this on pythonmac-sig, please.
128
Tim Peters7eea37e2001-09-04 22:08:56 +0000129C API
130
131- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000132
Tim Peters9fffa3e2001-09-04 05:14:19 +0000133- Note that PyLong_AsDouble can fail! This has always been true, but no
134 callers checked for it. It's more likely to fail now, because overflow
135 errors are properly detected now. The proper way to check:
136
137 double x = PyLong_AsDouble(some_long_object);
138 if (x == -1.0 && PyErr_Occurred()) {
139 /* The conversion failed. */
140 }
141
Tim Petersbdee63f2001-09-02 03:40:59 +0000142- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000143 compile but will not participate in GC. To upgrade an extension
144 module:
145
146 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000147
Neil Schemenauer4042c692001-08-30 15:38:01 +0000148 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
149 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000150
Neil Schemenauer4042c692001-08-30 15:38:01 +0000151 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
152 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000153
Neil Schemenauer4042c692001-08-30 15:38:01 +0000154 - remove PyGC_HEAD_SIZE from object size calculations
155
156 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
157
Tim Petersbdee63f2001-09-02 03:40:59 +0000158- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000159 These can be used safely to construct string objects from a
160 sprintf-style format string (similar to the format string supported
161 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000162
Tim Petersedc99312001-08-22 21:36:50 +0000163New platforms
164
Tim Petersb7da0902001-09-02 23:01:43 +0000165- Stephen Hansen contributed patches sufficient to get a clean compile
166 under Borland C (Windows), but he reports problems running it and ran
167 out of time to complete the port. Volunteers? Expect a MemoryError
168 when importing the types module; this is probably shallow, and
169 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000170
Tim Petersedc99312001-08-22 21:36:50 +0000171Tests
172
173Windows
174
Tim Peters6e13a562001-09-06 00:32:15 +0000175- Large file support is now enabled on Win32 platforms as well as on
176 Win64. This means that, for example, you can use f.tell() and f.seek()
177 to manipulate files larger than 2 gigabytes (provided you have enough
178 disk space, and are using a Windows filesystem that supports large
179 partitions).
180
Tim Petersbdee63f2001-09-02 03:40:59 +0000181- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000182 points to command.com (patch from Brian Quinlan).
183
Tim Petersedc99312001-08-22 21:36:50 +0000184
Tim Peters20f51a72001-07-21 02:31:40 +0000185What's New in Python 2.2a2?
186===========================
187
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000188Build
189
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000190- Tim Peters developed a brand new Windows installer using Wise 8.1,
191 generously donated to us by Wise Solutions.
192
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000193- configure supports a new option --enable-unicode, with the values
194 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
195 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000196
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000197- A new configure option --enable-framework builds a Mac OS X framework,
198 which "make frameworkinstall" will install. This provides a starting
199 point for more mac-like functionality, join pythonmac-sig@python.org
200 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000201
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000202- The NeXT platform is no longer supported.
203
204- The `new' module is now statically linked.
205
Tim Peters0afb6092001-08-15 06:06:44 +0000206Tools
207
208- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000209 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000210 the module docstring for details.
211
Tim Peters20f51a72001-07-21 02:31:40 +0000212Tests
213
Tim Peters5e824c32001-08-12 22:25:01 +0000214- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000215 platforms, allowing to give clearer test result output. regrtest
216 also has optional --use/-u switch to run normally disabled tests
217 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000218
Tim Peters20f51a72001-07-21 02:31:40 +0000219- Several new tests in the standard test suite, with special thanks to
220 Nick Mathewson.
221
222Core
223
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000224- The floor division operator // has been added as outlined in PEP
225 238. The / operator still provides classic division (and will until
226 Python 3.0) unless "from __future__ import division" is included, in
227 which case the / operator will provide true division. The operator
228 module provides truediv() and floordiv() functions. Augmented
229 assignment variants are included, as are the equivalent overloadable
230 methods and C API methods. See the PEP for a full discussion:
231 <http://python.sf.net/peps/pep-0238.html>
232
Tim Peters6cd6a822001-08-17 22:11:27 +0000233- Future statements are now effective in simulated interactive shells
234 (like IDLE). This should "just work" by magic, but read Michael
235 Hudson's "Future statements in simulated shells" PEP 264 for full
236 details: <http://python.sf.net/peps/pep-0264.html>.
237
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000238- The type/class unification (PEP 252-253) was integrated into the
239 trunk and is not so tentative any more (the exact specification of
240 some features is still tentative). A lot of work has done on fixing
241 bugs and adding robustness and features (performance still has to
242 come a long way).
243
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000244- Warnings about a mismatch in the Python API during extension import
245 now use the Python warning framework (which makes it possible to
246 write filters for these warnings).
247
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000248- A function's __dict__ (aka func_dict) will now always be a
249 dictionary. It used to be possible to delete it or set it to None,
250 but now both actions raise TypeErrors. It is still legal to set it
251 to a dictionary object. Getting func.__dict__ before any attributes
252 have been assigned now returns an empty dictionary instead of None.
253
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000254- A new command line option, -E, was added which disables the use of
255 all environment variables, or at least those that are specifically
256 significant to Python. Usually those have a name starting with
257 "PYTHON". This was used to fix a problem where the tests fail if
258 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
259 older distribution.
260
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000261Library
262
Tim Peters5e824c32001-08-12 22:25:01 +0000263- New class Differ and new functions ndiff() and restore() in difflib.py.
264 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000265 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000266
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000267- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
268 value using the minimal quoting required for the value; more
269 reliable than using xml.sax.saxutils.escape() for attribute values.
270
271- Readline completion support for cmd.Cmd was added.
272
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000273- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
274
275- Added function threading.BoundedSemaphore()
276
277- Added Ka-Ping Yee's cgitb.py module.
278
279- The `new' module now exposes the CO_xxx flags.
280
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000281New platforms
282
283C API
284
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000285- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
286 which provide a cross-platform implementations for the
287 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
288 the standard sprintf() and vsprintf() C lib APIs, these versions
289 apply bounds checking on the used buffer which enhances protection
290 against buffer overruns.
291
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000292- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000293 and extensions using different Unicode widths is rendered next to
294 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000295 will result in an ImportError. Unicode extensions writers must make
296 sure to check the Unicode width compatibility in their extensions by
297 using at least one of the mangled Unicode APIs in the extension.
298
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000299- Two new flags METH_NOARGS and METH_O are available in method definition
300 tables to simplify implementation of methods with no arguments and a
301 single untyped argument. Calling such methods is more efficient than
302 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
303 deprecated.
304
Tim Petersc1731372001-08-04 08:12:36 +0000305Windows
306
307- "import module" now compiles module.pyw if it exists and nothing else
308 relevant is found.
309
Tim Peters20f51a72001-07-21 02:31:40 +0000310
Guido van Rossum55a78992001-07-17 17:22:32 +0000311What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000312===========================
313
314Core
Tim Petersa814db52001-05-14 07:05:58 +0000315
Tim Peters6d6c1a32001-08-02 04:15:00 +0000316- TENTATIVELY, a large amount of code implementing much of what's
317 described in PEP 252 (Making Types Look More Like Classes) and PEP
318 253 (Subtyping Built-in Types) was added. This will be released
319 with Python 2.2a1. Documentation will be provided separately
320 through http://www.python.org/2.2/. The purpose of releasing this
321 with Python 2.2a1 is to test backwards compatibility. It is
322 possible, though not likely, that a decision is made not to release
323 this code as part of 2.2 final, if any serious backwards
324 incompapatibilities are found during alpha testing that cannot be
325 repaired.
326
Guido van Rossum55a78992001-07-17 17:22:32 +0000327- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000328 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000329 more 'yield' statements. See PEP 255. Since this adds a new
330 keyword to the language, this feature must be enabled by including a
331 future statement: "from __future__ import generators" (see PEP 236).
332 Generators will become a standard feature in a future release
333 (probably 2.3). Without this future statement, 'yield' remains an
334 ordinary identifier, but a warning is issued each time it is used.
335 (These warnings currently don't conform to the warnings framework of
336 PEP 230; we intend to fix this in 2.2a2.)
337
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000338- The UTF-16 codec was modified to be more RFC compliant. It will now
339 only remove BOM characters at the start of the string and then
340 only if running in native mode (UTF-16-LE and -BE won't remove a
341 leading BMO character).
342
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000343- Strings now have a new method .decode() to complement the already
344 existing .encode() method. These two methods provide direct access
345 to the corresponding decoders and encoders of the registered codecs.
346
347 To enhance the usability of the .encode() method, the special
348 casing of Unicode object return values was dropped (Unicode objects
349 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000350
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000351 Both methods will now return whatever the codec in charge of the
352 requested encoding returns as object, e.g. Unicode codecs will
353 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
354 will return u"äöü"). This enables codec writer to create codecs
355 for various simple to use conversions.
356
357 New codecs were added to demonstrate these new features (the .encode()
358 and .decode() columns indicate the type of the returned objects):
359
360 Name | .encode() | .decode() | Description
361 ----------------------------------------------------------------------
362 uu | string | string | UU codec (e.g. for email)
363 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000364 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000365 zlib | string | string | zlib compression
366 hex | string | string | 2-byte hex codec
367 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
368
Mark Hammond2a0af792001-05-14 03:09:36 +0000369- Some operating systems now support the concept of a default Unicode
370 encoding for file system operations. Notably, Windows supports 'mbcs'
371 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000372 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000373 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000374
375 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000376 functions that return filenames (such as os.listdir()) to return Python
377 string objects pre-encoded using the default file system encoding for
378 the platform. As this encoding is likely to be different from Python's
379 default encoding, converting this name to a Unicode object before passing
380 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000381 would attempt to use its default encoding (generally ASCII) rather than
382 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000383
Tim Petersa814db52001-05-14 07:05:58 +0000384 In general, this change simply removes surprises when working with
385 Unicode and the file system, making these operations work as you expect,
386 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000387 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000388
Tim Peters61dff2b2001-05-08 15:43:37 +0000389- Float (and complex) literals in source code were evaluated to full
390 precision only when running from a .py file; the same code loaded from a
391 .pyc (or .pyo) file could suffer numeric differences starting at about the
392 12th significant decimal digit. For example, on a machine with IEEE-754
393 floating arithmetic,
394
395 x = 9007199254740992.0
396 print long(x)
397
398 printed 9007199254740992 if run directly from .py, but 9007199254740000
399 if from a compiled (.pyc or .pyo) file. This was due to marshal using
400 str(float) instead of repr(float) when building code objects. marshal
401 now uses repr(float) instead, which should reproduce floats to full
402 machine precision (assuming the platform C float<->string I/O conversion
403 functions are of good quality).
404
405 This may cause floating-point results to change in some cases, and
406 usually for the better, but may also cause numerically unstable
407 algorithms to break.
408
Tim Peters2f228e72001-05-13 00:19:31 +0000409- The implementation of dicts suffers fewer collisions, which has speed
410 benefits. However, the order in which dict entries appear in dict.keys(),
411 dict.values() and dict.items() may differ from previous releases for a
412 given dict. Nothing is defined about this order, so no program should
413 rely on it. Nevertheless, it's easy to write test cases that rely on the
414 order by accident, typically because of printing the str() or repr() of a
415 dict to an "expected results" file. See Lib/test/test_support.py's new
416 sortdict(dict) function for a simple way to display a dict in sorted
417 order.
418
Tim Peters7a3bfc32001-06-12 01:22:22 +0000419- Many other small changes to dicts were made, resulting in faster
420 operation along the most common code paths.
421
Guido van Rossum10315822001-05-01 20:54:30 +0000422- Dictionary objects now support the "in" operator: "x in dict" means
423 the same as dict.has_key(x).
424
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000425- The update() method of dictionaries now accepts generic mapping
426 objects. Specifically the argument object must support the .keys()
427 and __getitem__() methods. This allows you to say, for example,
428 {}.update(UserDict())
429
Guido van Rossum10315822001-05-01 20:54:30 +0000430- Iterators were added; this is a generalized way of providing values
431 to a for loop. See PEP 234. There's a new built-in function iter()
432 to return an iterator. There's a new protocol to get the next value
433 from an iterator using the next() method (in Python) or the
434 tp_iternext slot (in C). There's a new protocol to get iterators
435 using the __iter__() method (in Python) or the tp_iter slot (in C).
436 Iterating (i.e. a for loop) over a dictionary generates its keys.
437 Iterating over a file generates its lines.
438
Tim Petersf553f892001-05-01 20:45:31 +0000439- The following functions were generalized to work nicely with iterator
440 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000441 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000442 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
443 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000444 join() method of strings
445 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000446 'x in y' and 'x not in y' (PySequence_Contains() in C API)
447 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000448 right-hand side of assignment statements with multiple targets, such as
449 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000450
Tim Petersd85e1022001-05-11 21:51:48 +0000451- Accessing module attributes is significantly faster (for example,
452 random.random or os.path or yourPythonModule.yourAttribute).
453
Tim Peterse63415e2001-05-08 04:38:29 +0000454- Comparing dictionary objects via == and != is faster, and now works even
455 if the keys and values don't support comparisons other than ==.
456
Tim Peters95bf9392001-05-10 08:32:44 +0000457- Comparing dictionaries in ways other than == and != is slower: there were
458 insecurities in the dict comparison implementation that could cause Python
459 to crash if the element comparison routines for the dict keys and/or
460 values mutated the dicts. Making the code bulletproof slowed it down.
461
Tim Peterseb28ef22001-06-02 05:27:19 +0000462- Collisions in dicts are resolved via a new approach, which can help
463 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000464 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000465 faster now. Thanks to Christian Tismer for pointing out the cause and
466 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000467
Tim Peters52e155e2001-06-16 05:42:57 +0000468- repr() is much faster for large containers (dict, list, tuple).
469
470
Tim Petersa814db52001-05-14 07:05:58 +0000471Library
472
Fred Drake960fdf92001-07-20 18:38:26 +0000473- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
474 were added to the string module. These a locale-indenpendent
475 constants, unlike letters, lowercase, and uppercase. These are now
476 use in appropriate locations in the standard library.
477
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000478- The flags used in dlopen calls can now be configured using
479 sys.setdlopenflags and queried using sys.getdlopenflags.
480
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000481- Fredrik Lundh's xmlrpclib is now a standard library module. This
482 provides full client-side XML-RPC support. In addition,
483 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
484 one asyncore-based). Thanks to Eric Raymond for the documentation.
485
Guido van Rossum643d3912001-07-05 14:46:25 +0000486- The xrange() object is simplified: it no longer supports slicing,
487 repetition, comparisons, efficient 'in' checking, the tolist()
488 method, or the start, stop and step attributes. See PEP 260.
489
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000490- A new function fnmatch.filter to filter lists of file names was added.
491
Barry Warsawffd674d2001-05-22 16:00:10 +0000492- calendar.py uses month and day names based on the current locale.
493
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000494- strop is now *really* obsolete (this was announced before with 1.6),
495 and issues DeprecationWarning when used (except for the four items
496 that are still imported into string.py).
497
Tim Petersa814db52001-05-14 07:05:58 +0000498- Cookie.py now sorts key+value pairs by key in output strings.
499
500- pprint.isrecursive(object) didn't correctly identify recursive objects.
501 Now it does.
502
Tim Peters95b3f782001-05-14 18:39:41 +0000503- pprint functions now much faster for large containers (tuple, list, dict).
504
Tim Peters7b9542a2001-06-10 23:40:19 +0000505- New 'q' and 'Q' format codes in the struct module, corresponding to C
506 types "long long" and "unsigned long long" (on Windows, __int64). In
507 native mode, these can be used only when the platform C compiler supports
508 these types (when HAVE_LONG_LONG is #define'd by the Python config
509 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000510 In standard mode, 'q' and 'Q' are supported on all platforms, and are
511 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000512
Guido van Rossum83213cc2001-06-12 16:48:52 +0000513- The site module installs a new built-in function 'help' that invokes
514 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
515 it displays a message reminding the user to use 'help()' or
516 'help(object)'.
517
Tim Petersa814db52001-05-14 07:05:58 +0000518Tests
519
520- New test_mutants.py runs dict comparisons where the key and value
521 comparison operators mutute the dicts randomly during comparison. This
522 rapidly causes Python to crash under earlier releases (not for the faint
523 of heart: it can also cause Win9x to freeze or reboot!).
524
525- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000526 pprint.isreadable() return sensible results. Also verifies that simple
527 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000528
Tim Peters4324aa32001-05-28 22:30:08 +0000529C API
530
531- Removed the unused last_is_sticky argument from the internal
532 _PyTuple_Resize(). If this affects you, you were cheating.
533
534
Guido van Rossum55a78992001-07-17 17:22:32 +0000535======================================================================
536
537
Guido van Rossumffe13be2001-04-16 18:46:45 +0000538What's New in Python 2.1 (final)?
539=================================
540
541We only changed a few things since the last release candidate, all in
542Python library code:
543
544- A bug in the locale module was fixed that affected locales which
545 define no grouping for numeric formatting.
546
547- A few bugs in the weakref module's implementations of weak
548 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
549 and the test suite was updated to check for these bugs.
550
551- An old bug in the os.path.walk() function (introduced in Python
552 2.0!) was fixed: a non-existent file would cause an exception
553 instead of being ignored.
554
555- Fixed a few bugs in the new symtable module found by Neil Norwitz's
556 PyChecker.
557
558
Guido van Rossum5b08f132001-04-16 02:05:23 +0000559What's New in Python 2.1c2?
560===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000561
Guido van Rossum5b08f132001-04-16 02:05:23 +0000562A flurry of small changes, and one showstopper fixed in the nick of
563time made it necessary to release another release candidate. The list
564here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000565
Guido van Rossum5b08f132001-04-16 02:05:23 +0000566Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000567
Guido van Rossum5b08f132001-04-16 02:05:23 +0000568- Tim discovered a nasty bug in the dictionary code, caused by
569 PyDict_Next() calling dict_resize(), and the GC code's use of
570 PyDict_Next() violating an assumption in dict_items(). This was
571 fixed with considerable amounts of band-aid, but the net effect is a
572 saner and more robust implementation.
573
574- Made a bunch of symbols static that were accidentally global.
575
576Build and Ports
577
578- The setup.py script didn't check for a new enough version of zlib
579 (1.1.3 is needed). Now it does.
580
581- Changed "make clean" target to also remove shared libraries.
582
583- Added a more general warning about the SGI Irix optimizer to README.
584
585Library
586
587- Fix a bug in urllib.basejoin("http://host", "../file.html") which
588 omitted the slash between host and file.html.
589
590- The mailbox module's _Mailbox class contained a completely broken
591 and undocumented seek() method. Ripped it out.
592
593- Fixed a bunch of typos in various library modules (urllib2, smtpd,
594 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
595
596- Fixed a few last-minute bugs in unittest.
597
598Extensions
599
600- Reverted the patch to the OpenSSL code in socketmodule.c to support
601 RAND_status() and the EGD, and the subsequent patch that tried to
602 fix it for pre-0.9.5 versions; the problem with the patch is that on
603 some systems it issues a warning whenever socket is imported, and
604 that's unacceptable.
605
606Tests
607
608- Fixed the pickle tests to work with "import test.test_pickle".
609
610- Tweaked test_locale.py to actually run the test Windows.
611
612- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
613 not "wb" (which is not a valid mode at all).
614
615- Fix pstats browser crashes. Import readline if it exists to make
616 the user interface nicer.
617
618- Add "import thread" to the top of test modules that import the
619 threading module (test_asynchat and test_threadedtempfile). This
620 prevents test failures caused by a broken threading module resulting
621 from a previously caught failed import.
622
623- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
624 needed on some platforms (e.g. Solaris 8) when the tests are run
625 twice in succession.
626
627- Skip rather than fail test_sunaudiodev if no audio device is found.
628
629
630What's New in Python 2.1c1?
631===========================
632
633This list was significantly updated when 2.1c2 was released; the 2.1c1
634release didn't mention most changes that were actually part of 2.1c1:
635
636Legal
637
638- Copyright was assigned to the Python Software Foundation (PSF) and a
639 PSF license (very similar to the CNRI license) was added.
640
641- The CNRI copyright notice was updated to include 2001.
642
643Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000644
Guido van Rossumc9932722001-04-12 02:31:27 +0000645- After a public outcry, assignment to __debug__ is no longer illegal;
646 instead, a warning is issued. It will become illegal in 2.2.
647
Guido van Rossum5b08f132001-04-16 02:05:23 +0000648- Fixed a core dump with "%#x" % 0, and changed the semantics so that
649 "%#x" now always prepends "0x", even if the value is zero.
650
651- Fixed some nits in the bytecode compiler.
652
653- Fixed core dumps when calling certain kinds of non-functions.
654
655- Fixed various core dumps caused by reference count bugs.
656
657Build and Ports
658
659- Use INSTALL_SCRIPT to install script files.
660
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000661- New port: SCO Unixware 7, by Billy G. Allie.
662
Guido van Rossum5b08f132001-04-16 02:05:23 +0000663- Updated RISCOS port.
664
665- Updated BeOS port and notes.
666
667- Various other porting problems resolved.
668
669Library
670
671- The TERMIOS and SOCKET modules are now truly obsolete and
672 unnecessary. Their symbols are incorporated in the termios and
673 socket modules.
674
675- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
676 better tests for pickling.
677
678- threading: make Condition.wait() robust against KeyboardInterrupt.
679
680- zipfile: add support to zipfile to support opening an archive
681 represented by an open file rather than a file name. Fix bug where
682 the archive was not properly closed. Fixed a bug in this bugfix
683 where flush() was called for a read-only file.
684
685- imputil: added an uninstall() method to the ImportManager.
686
687- Canvas: fixed bugs in lower() and tkraise() methods.
688
689- SocketServer: API change (added overridable close_request() method)
690 so that the TCP server can explicitly close the request.
691
692- pstats: Eric Raymond added a simple interactive statistics browser,
693 invoked when the module is run as a script.
694
695- locale: fixed a problem in format().
696
697- webbrowser: made it work when the BROWSER environment variable has a
698 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
699 KDE 2. Fixed some other nits.
700
701- unittest: changes to allow using a different exception than
702 AssertionError, and added a few more function aliases. Some other
703 small changes.
704
705- urllib, urllib2: fixed redirect problems and a coupleof other nits.
706
707- asynchat: fixed a critical bug in asynchat that slipped through the
708 2.1b2 release. Fixed another rare bug.
709
710- Fix some unqualified except: clauses (always a bad code example).
711
712XML
713
714- pyexpat: new API get_version_string().
715
716- Fixed some minidom bugs.
717
718Extensions
719
720- Fixed a core dump in _weakref. Removed the weakref.mapping()
721 function (it adds nothing to the API).
722
723- Rationalized the use of header files in the readline module, to make
724 it compile (albeit with some warnings) with the very recent readline
725 4.2, without breaking for earlier versions.
726
727- Hopefully fixed a buffering problem in linuxaudiodev.
728
729- Attempted a fix to make the OpenSSL support in the socket module
730 work again with pre-0.9.5 versions of OpenSSL.
731
732Tests
733
734- Added a test case for asynchat and asyncore.
735
736- Removed coupling between tests where one test failing could break
737 another.
738
739Tools
740
741- Ping added an interactive help browser to pydoc, fixed some nits
742 in the rest of the pydoc code, and added some features to his
743 inspect module.
744
745- An updated python-mode.el version 4.1 which integrates Ken
746 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
747 much nicer in XEmacs and Emacs. When stepping through your program
748 with pdb, in either the shell window or the *Python* window, the
749 source file and line will be tracked by an arrow. Very cool!
750
751- IDLE: syntax warnings in interactive mode are changed into errors.
752
753- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000754 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000755
756- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000757
Barry Warsaw11e89c72001-04-11 20:37:57 +0000758
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000759What's New in Python 2.1 beta 2?
760================================
761
Guido van Rossum053ae352001-03-22 14:17:21 +0000762(Unlisted are many fixed bugs, more documentation, etc.)
763
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000764Core language, builtins, and interpreter
765
Guido van Rossum053ae352001-03-22 14:17:21 +0000766- The nested scopes work (enabled by "from __future__ import
767 nested_scopes") is completed; in particular, the future now extends
768 into code executed through exec, eval() and execfile(), and into the
769 interactive interpreter.
770
771- When calling a base class method (e.g. BaseClass.__init__(self)),
772 this is now allowed even if self is not strictly spoken a class
773 instance (e.g. when using metaclasses or the Don Beaudry hook).
774
775- Slice objects are now comparable but not hashable; this prevents
776 dict[:] from being accepted but meaningless.
777
778- Complex division is now calculated using less braindead algorithms.
779 This doesn't change semantics except it's more likely to give useful
780 results in extreme cases. Complex repr() now uses full precision
781 like float repr().
782
783- sgmllib.py now calls handle_decl() for simple <!...> declarations.
784
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000785- It is illegal to assign to the name __debug__, which is set when the
786 interpreter starts. It is effectively a compile-time constant.
787
788- A warning will be issued if a global statement for a variable
789 follows a use or assignment of that variable.
790
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000791Standard library
792
Guido van Rossum053ae352001-03-22 14:17:21 +0000793- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
794 inspired by JUnit), is now part of the standard library. You now
795 have a choice of two testing frameworks: unittest requires you to
796 write testcases as separate code, doctest gathers them from
797 docstrings. Both approaches have their advantages and
798 disadvantages.
799
800- A new module Tix was added, which wraps the Tix extension library
801 for Tk. With that module, it is not necessary to statically link
802 Tix with _tkinter, since Tix will be loaded with Tcl's "package
803 require" command. See Demo/tix/.
804
805- tzparse.py is now obsolete.
806
807- In gzip.py, the seek() and tell() methods are removed -- they were
808 non-functional anyway, and it's better if callers can test for their
809 existence with hasattr().
810
811Python/C API
812
813- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
814 that's already in the dictionary during a PyDict_Next() iteration.
815 This used to fail occasionally when a dictionary resize operation
816 could be triggered that would rehash all the keys. All other
817 modifications to the dictionary are still off-limits during a
818 PyDict_Next() iteration!
819
820- New extended APIs related to passing compiler variables around.
821
822- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
823 implement isinstance() and issubclass().
824
825- Py_BuildValue() now has a "D" conversion to create a Python complex
826 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000827
Fred Drake4e262a92001-03-22 18:26:47 +0000828- Extensions types which support weak references must now set the
829 field allocated for the weak reference machinery to NULL themselves;
830 this is done to avoid the cost of checking each object for having a
831 weakly referencable type in PyObject_INIT(), since most types are
832 not weakly referencable.
833
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000834- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
835 free variables and cell variables to and from the frame's f_locals.
836
837- Variants of several functions defined in pythonrun.h have been added
838 to support the nested_scopes future statement. The variants all end
839 in Flags and take an extra argument, a PyCompilerFlags *; examples:
840 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
841 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000842 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000843
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000844Distutils
845
846- the sdist command now writes a PKG-INFO file, as described in PEP 241,
847 into the release tree.
848
Tim Peters0e57abf2001-05-02 07:39:38 +0000849- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000850 (an uninstaller, more customization of the installer's display)
851
852- from Jack Jansen: added Mac-specific code to generate a dialog for
853 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000854 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000855 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000856
857- added 'platforms' and 'keywords' to the set of metadata that can be
858 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000859
860- applied patches from Jason Tishler to make the compiler class work with
861 Cygwin.
862
863
Tim Peters2fe289a2001-03-01 22:19:38 +0000864What's New in Python 2.1 beta 1?
865================================
Tim Petersd66595f2001-02-04 03:09:53 +0000866
867Core language, builtins, and interpreter
868
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000869- Following an outcry from the community about the amount of code
870 broken by the nested scopes feature introduced in 2.1a2, we decided
871 to make this feature optional, and to wait until Python 2.2 (or at
872 least 6 months) to make it standard. The option can be enabled on a
873 per-module basis by adding "from __future__ import nested_scopes" at
874 the beginning of a module (before any other statements, but after
875 comments and an optional docstring). See PEP 236 (Back to the
876 __future__) for a description of the __future__ statement. PEP 227
877 (Statically Nested Scopes) has been updated to reflect this change,
878 and to clarify the semantics in a number of endcases.
879
880- The nested scopes code, when enabled, has been hardened, and most
881 bugs and memory leaks in it have been fixed.
882
883- Compile-time warnings are now generated for a number of conditions
884 that will break or change in meaning when nested scopes are enabled:
885
886 - Using "from...import *" or "exec" without in-clause in a function
887 scope that also defines a lambda or nested function with one or
888 more free (non-local) variables. The presence of the import* or
889 bare exec makes it impossible for the compiler to determine the
890 exact set of local variables in the outer scope, which makes it
891 impossible to determine the bindings for free variables in the
892 inner scope. To avoid the warning about import *, change it into
893 an import of explicitly name object, or move the import* statement
894 to the global scope; to avoid the warning about bare exec, use
895 exec...in... (a good idea anyway -- there's a possibility that
896 bare exec will be deprecated in the future).
897
898 - Use of a global variable in a nested scope with the same name as a
899 local variable in a surrounding scope. This will change in
900 meaning with nested scopes: the name in the inner scope will
901 reference the variable in the outer scope rather than the global
902 of the same name. To avoid the warning, either rename the outer
903 variable, or use a global statement in the inner function.
904
Neil Schemenauera35c6882001-02-27 04:45:05 +0000905- An optional object allocator has been included. This allocator is
906 optimized for Python objects and should be faster and use less memory
907 than the standard system allocator. It is not enabled by default
908 because of possible thread safety problems. The allocator is only
909 protected by the Python interpreter lock and it is possible that some
910 extension modules require a thread safe allocator. The object
911 allocator can be enabled by providing the "--with-pymalloc" option to
912 configure.
913
Tim Petersd66595f2001-02-04 03:09:53 +0000914Standard library
915
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000916- pyexpat now detects the expat version if expat.h defines it. A
917 number of additional handlers are provided, which are only available
918 since expat 1.95. In addition, the methods SetParamEntityParsing and
919 GetInputContext of Parser objects are available with 1.95.x
920 only. Parser objects now provide the ordered_attributes and
921 specified_attributes attributes. A new module expat.model was added,
922 which offers a number of additional constants if 1.95.x is used.
923
924- xml.dom offers the new functions registerDOMImplementation and
925 getDOMImplementation.
926
927- xml.dom.minidom offers a toprettyxml method. A number of DOM
928 conformance issues have been resolved. In particular, Element now
929 has an hasAttributes method, and the handling of namespaces was
930 improved.
931
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000932- Ka-Ping Yee contributed two new modules: inspect.py, a module for
933 getting information about live Python code, and pydoc.py, a module
934 for interactively converting docstrings to HTML or text.
935 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000936 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000937 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
938 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000939
Tim Peters1eff7962001-03-01 02:31:33 +0000940- New library module difflib.py, primarily packaging the SequenceMatcher
941 class at the heart of the popular ndiff.py file-comparison tool.
942
943- doctest.py (a framework for verifying Python code examples in docstrings)
944 is now part of the std library.
945
Tim Petersd66595f2001-02-04 03:09:53 +0000946Windows changes
947
Guido van Rossume3955a82001-03-02 14:05:59 +0000948- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
949 small GUI that lets you browse the module docstrings using your
950 default web browser.
951
Tim Peters1eff7962001-03-01 02:31:33 +0000952- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
953 Platforms) is implemented. See
954
955 http://python.sourceforge.net/peps/pep-0235.html
956
957 for full details, especially the "Current Lower-Left Semantics" section.
958 The new Windows import rules are simpler than before:
959
960 A. If the PYTHONCASEOK environment variable exists, same as
961 before: silently accept the first case-insensitive match of any
962 kind; raise ImportError if none found.
963
964 B. Else search sys.path for the first case-sensitive match; raise
965 ImportError if none found.
966
967 The same rules have been implented on other platforms with case-
968 insensitive but case-preserving filesystems too (including Cygwin, and
969 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000970
Tim Peters25a9ce32001-02-19 07:06:36 +0000971- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
972 what it's supposed to do (and does do under NT and 2000) via direct
973 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000974 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000975 all Win9x systems before.
976
Tim Peters1eff7962001-03-01 02:31:33 +0000977- Build: Subproject _test (effectively) renamed to _testcapi.
978
Tim Peters2fe289a2001-03-01 22:19:38 +0000979New platforms
980
981- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
982 Thanks to Steven Majewski!
983
984- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
985 Tishler!
986
Guido van Rossum9089b272001-03-02 06:49:50 +0000987- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
988 Schwertberger! See RISCOS/README for more information -- it seems
989 that because of the bizarre filename conventions on RISCOS, no port
990 to that platform is easy. Note that the new variable os.endsep is
991 silently supported in order to make life easier on this platform,
992 but we don't advertise it because it's not worth for most folks to
993 care about RISCOS portability.
994
Tim Peters25a9ce32001-02-19 07:06:36 +0000995
Tim Petersd7b5e882001-01-25 03:36:26 +0000996What's New in Python 2.1 alpha 2?
997=================================
Tim Peters40ead762001-01-27 05:35:26 +0000998
Tim Petersd7b5e882001-01-25 03:36:26 +0000999Core language, builtins, and interpreter
1000
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001001- Scopes nest. If a name is used in a function or class, but is not
1002 local, the definition in the nearest enclosing function scope will
1003 be used. One consequence of this change is that lambda statements
1004 could reference variables in the namespaces where the lambda is
1005 defined. In some unusual cases, this change will break code.
1006
1007 In all previous version of Python, names were resolved in exactly
1008 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001009 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001010 function A is defined within a function B, the names bound in B are
1011 not visible in A. The new rules make names bound in B visible in A,
1012 unless A contains a name binding that hides the binding in B.
1013
1014 Section 4.1 of the reference manual describes the new scoping rules
1015 in detail. The test script in Lib/test/test_scope.py demonstrates
1016 some of the effects of the change.
1017
1018 The new rules will cause existing code to break if it defines nested
1019 functions where an outer function has local variables with the same
1020 name as globals or builtins used by the inner function. Example:
1021
1022 def munge(str):
1023 def helper(x):
1024 return str(x)
1025 if type(str) != type(''):
1026 str = helper(str)
1027 return str.strip()
1028
1029 Under the old rules, the name str in helper() is bound to the
1030 builtin function str(). Under the new rules, it will be bound to
1031 the argument named str and an error will occur when helper() is
1032 called.
1033
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001034- The compiler will report a SyntaxError if "from ... import *" occurs
1035 in a function or class scope. The language reference has documented
1036 that this case is illegal, but the compiler never checked for it.
1037 The recent introduction of nested scope makes the meaning of this
1038 form of name binding ambiguous. In a future release, the compiler
1039 may allow this form when there is no possibility of ambiguity.
1040
Tim Peters40ead762001-01-27 05:35:26 +00001041- repr(string) is easier to read, now using hex escapes instead of octal,
1042 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1043
1044 >>> "\texample \r\n" + chr(0) + chr(255)
1045 '\texample \r\n\x00\xff' # in 2.1
1046 '\011example \015\012\000\377' # in 2.0
1047
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001048- Functions are now compared and hashed by identity, not by value, since
1049 the func_code attribute is writable.
1050
Fred Drakefb9d7122001-02-01 20:00:40 +00001051- Weak references (PEP 205) have been added. This involves a few
1052 changes in the core, an extension module (_weakref), and a Python
1053 module (weakref). The weakref module is the public interface. It
1054 includes support for "explicit" weak references, proxy objects, and
1055 mappings with weakly held values.
1056
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001057- A 'continue' statement can now appear in a try block within the body
1058 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001059 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001060
Tim Petersd7b5e882001-01-25 03:36:26 +00001061Standard library
1062
Barry Warsaw30dbd142001-01-31 22:14:01 +00001063- mailbox.py now has a new class, PortableUnixMailbox which is
1064 identical to UnixMailbox but uses a more portable scheme for
1065 determining From_ separators. Also, the constructors for all the
1066 classes in this module have a new optional `factory' argument, which
1067 is a callable used when new message classes must be instantiated by
1068 the next() method.
1069
Tim Petersd7b5e882001-01-25 03:36:26 +00001070- random.py is now self-contained, and offers all the functionality of
1071 the now-deprecated whrandom.py. See the docs for details. random.py
1072 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001073 and restoring the internal state of the generator; and jumpahead(n),
1074 for quickly forcing the internal state to be the same as if n calls to
1075 random() had been made. The latter is particularly useful for multi-
1076 threaded programs, creating one instance of the random.Random() class for
1077 each thread, then using .jumpahead() to force each instance to use a
1078 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001079
Tim Peters0de88fc2001-02-01 04:59:18 +00001080- random.py's seed() function is new. For bit-for-bit compatibility with
1081 prior releases, use the whseed function instead. The new seed function
1082 addresses two problems: (1) The old function couldn't produce more than
1083 about 2**24 distinct internal states; the new one about 2**45 (the best
1084 that can be done in the Wichmann-Hill generator). (2) The old function
1085 sometimes produced identical internal states when passed distinct
1086 integers, and there was no simple way to predict when that would happen;
1087 the new one guarantees to produce distinct internal states for all
1088 arguments in [0, 27814431486576L).
1089
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001090- The socket module now supports raw packets on Linux. The socket
1091 family is AF_PACKET.
1092
Tim Peters9ea17ac2001-02-02 05:57:15 +00001093- test_capi.py is a start at running tests of the Python C API. The tests
1094 are implemented by the new Modules/_testmodule.c.
1095
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001096- A new extension module, _symtable, provides provisional access to the
1097 internal symbol table used by the Python compiler. A higher-level
1098 interface will be added on top of _symtable in a future release.
1099
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001100- Removed the obsolete soundex module.
1101
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001102- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1103 the isSameNode method; NamedNodeMap the get method.
1104
1105- xml.sax.expatreader supports the lexical handler property; it
1106 generates comment, startCDATA, and endCDATA events.
1107
Tim Petersee826f82001-01-31 19:39:44 +00001108Windows changes
1109
1110- Build procedure: the zlib project is built in a different way that
1111 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001112 the zlib binary used. See PCbuild\readme.txt for details. Your old
1113 zlib-related directories can be deleted; you'll need to download fresh
1114 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001115
Tim Peters9ea17ac2001-02-02 05:57:15 +00001116- Build: New subproject _test for the benefit of test_capi.py (see above).
1117
Tim Petersb16c56f2001-02-02 21:24:51 +00001118- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1119 interface to some Python compiler internals).
1120
1121- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001122 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001123
Tim Petersa3a3a032000-11-30 05:22:44 +00001124What's New in Python 2.1 alpha 1?
1125=================================
1126
1127Core language, builtins, and interpreter
1128
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001129- There is a new Unicode companion to the PyObject_Str() API
1130 called PyObject_Unicode(). It behaves in the same way as the
1131 former, but assures that the returned value is an Unicode object
1132 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001133
Guido van Rossumf98eda02001-01-17 15:54:45 +00001134- The comparison operators support "rich comparison overloading" (PEP
1135 207). C extension types can provide a rich comparison function in
1136 the new tp_richcompare slot in the type object. The cmp() function
1137 and the C function PyObject_Compare() first try the new rich
1138 comparison operators before trying the old 3-way comparison. There
1139 is also a new C API PyObject_RichCompare() (which also falls back on
1140 the old 3-way comparison, but does not constrain the outcome of the
1141 rich comparison to a Boolean result).
1142
1143 The rich comparison function takes two objects (at least one of
1144 which is guaranteed to have the type that provided the function) and
1145 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1146 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1147 object, which may be NotImplemented (in which case the tp_compare
1148 slot function is used as a fallback, if defined).
1149
1150 Classes can overload individual comparison operators by defining one
1151 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001152 __ge__. There are no explicit "reflected argument" versions of
1153 these; instead, __lt__ and __gt__ are each other's reflection,
1154 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1155 reflection (similar at the C level). No other implications are
1156 made; in particular, Python does not assume that == is the Boolean
1157 inverse of !=, or that < is the Boolean inverse of >=. This makes
1158 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001159
1160 Classes or types that want to implement (in)equality tests but not
1161 the ordering operators (i.e. unordered types) should implement ==
1162 and !=, and raise an error for the ordering operators.
1163
Guido van Rossuma88479f2001-01-18 14:28:08 +00001164 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001165 Boolean; e.g. a matrix type might want to return a matrix of bits
1166 for A < B, giving elementwise comparisons. Such types should ensure
1167 that any interpretation of their value in a Boolean context raises
1168 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1169 at the C level) to always raise an exception.
1170
Guido van Rossuma88479f2001-01-18 14:28:08 +00001171- Complex numbers use rich comparisons to define == and != but raise
1172 an exception for <, <=, > and >=. Unfortunately, this also means
1173 that cmp() of two complex numbers raises an exception when the two
1174 numbers differ. Since it is not mathematically meaningful to compare
1175 complex numbers except for equality, I hope that this doesn't break
1176 too much code.
1177
Tim Peters3389f192001-02-18 08:48:49 +00001178- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001179 not defined by the language, other than that it's arbitrary but
1180 consistent (see the Reference Manual). An implementation detail changed
1181 in 2.1a1 such that None now compares less than any other object. Code
1182 relying on this new behavior (like code that relied on the previous
1183 behavior) does so at its own risk.
1184
Barry Warsaw573b5412001-01-15 20:43:18 +00001185- Functions and methods now support getting and setting arbitrarily
1186 named attributes (PEP 232). Functions have a new __dict__
1187 (a.k.a. func_dict) which hold the function attributes. Methods get
1188 and set attributes on their underlying im_func. It is a TypeError
1189 to set an attribute on a bound method.
1190
Guido van Rossum051e3352001-01-15 19:11:10 +00001191- The xrange() object implementation has been improved so that
1192 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1193 limitation that in this case len(xrange(sys.maxint)) can't be
1194 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1195 work fine as long as the index i doesn't actually reach 2**31.
1196 (Python uses regular ints for sequence and string indices; fixing
1197 that is much more work.)
1198
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001199- Two changes to from...import:
1200
Guido van Rossumba381232001-02-03 15:06:40 +00001201 1) "from M import X" now works even if (after loading module M)
1202 sys.modules['M'] is not a real module; it's basically a getattr()
1203 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001204
1205 2) "from M import *" now looks for M.__all__ to decide which names to
1206 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1207 filters out names starting with '_' as before. Whether or not
1208 __all__ exists, there's no restriction on the type of M.
1209
Guido van Rossumf61f1662001-01-10 20:13:55 +00001210- File objects have a new method, xreadlines(). This is the fastest
1211 way to iterate over all lines in a file:
1212
1213 for line in file.xreadlines():
1214 ...do something to line...
1215
1216 See the xreadlines module (mentioned below) for how to do this for
1217 other file-like objects.
1218
1219- Even if you don't use file.xreadlines(), you may expect a speedup on
1220 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001221 quite a bit in platform-specific ways: on systems (like Linux) that
1222 support flockfile(), getc_unlocked(), and funlockfile(), those are
1223 used by default. On systems (like Windows) without getc_unlocked(),
1224 a complicated (but still thread-safe) method using fgets() is used by
1225 default.
1226
Tim Petersd52269b2001-01-25 06:23:18 +00001227 You can force use of the fgets() method by #define'ing
1228 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001229 getc_unlocked()).
1230
Tim Petersd52269b2001-01-25 06:23:18 +00001231 You can force fgets() not to be used by #define'ing
1232 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001233 test_bufio.py fails -- and let us know if it does!).
1234
1235- In addition, the fileinput module, while still slower than the other
1236 methods on most platforms, has been sped up too, by using
1237 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001238
1239- Support for run-time warnings has been added, including a new
1240 command line option (-W) to specify the disposition of warnings.
1241 See the description of the warnings module below.
1242
1243- Extensive changes have been made to the coercion code. This mostly
1244 affects extension modules (which can now implement mixed-type
1245 numerical operators without having to use coercion), but
1246 occasionally, in boundary cases the coercion semantics have changed
1247 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001248 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001249 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001250 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001251
Guido van Rossumf98eda02001-01-17 15:54:45 +00001252- In connection with the coercion changes, a new built-in singleton
1253 object, NotImplemented is defined. This can be returned for
1254 operations that wish to indicate they are not implemented for a
1255 particular combination of arguments. From C, this is
1256 Py_NotImplemented.
1257
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001258- The interpreter accepts now bytecode files on the command line even
1259 if they do not have a .pyc or .pyo extension. On Linux, after executing
1260
Martin v. Löwise214baa2001-02-04 22:37:56 +00001261import imp,sys,string
1262magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1263reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1264open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001265
1266 any byte code file can be used as an executable (i.e. as an argument
1267 to execve(2)).
1268
Tim Peters9940b802000-12-01 07:59:35 +00001269- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001270 character. In 1.6 and earlier, they never produced a sign,
1271 and raised an error if the value of the long was too large
1272 to fit in a Python int. In 2.0, they produced a sign if and
1273 only if too large to fit in an int. This was inconsistent
1274 across platforms (because the size of an int varies across
1275 platforms), and inconsistent with hex() and oct(). Example:
1276
1277 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001278 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001279 'ffffffbe' # in 2.0 and before, on 32-bit machines
1280 >>> hex(-0x42L)
1281 '-0x42L' # in all versions of Python
1282
Tim Peters9940b802000-12-01 07:59:35 +00001283 The behavior of %d formats for negative Python longs remains
1284 the same as in 2.0 (although in 1.6 and before, they raised
1285 an error if the long didn't fit in a Python int).
1286
1287 %u formats don't make sense for Python longs, but are allowed
1288 and treated the same as %d in 2.1. In 2.0, a negative long
1289 formatted via %u produced a sign if and only if too large to
1290 fit in an int. In 1.6 and earlier, a negative long formatted
1291 via %u raised an error if it was too big to fit in an int.
1292
Guido van Rossum3661d392000-12-12 22:10:31 +00001293- Dictionary objects have an odd new method, popitem(). This removes
1294 an arbitrary item from the dictionary and returns it (in the form of
1295 a (key, value) pair). This can be useful for algorithms that use a
1296 dictionary as a bag of "to do" items and repeatedly need to pick one
1297 item. Such algorithms normally end up running in quadratic time;
1298 using popitem() they can usually be made to run in linear time.
1299
Tim Peters36cdad12000-12-29 02:06:45 +00001300Standard library
1301
Thomas Woutersfe385252001-01-19 23:16:56 +00001302- In the time module, the time argument to the functions strftime,
1303 localtime, gmtime, asctime and ctime is now optional, defaulting to
1304 the current time (in the local timezone).
1305
Guido van Rossumda91f222001-01-15 16:36:08 +00001306- The ftplib module now defaults to passive mode, which is deemed a
1307 more useful default given that clients are often inside firewalls
1308 these days. Note that this could break if ftplib is used to connect
1309 to a *server* that is inside a firewall, from outside; this is
1310 expected to be a very rare situation. To fix that, you can call
1311 ftp.set_pasv(0).
1312
Martin v. Löwis10a27872001-01-13 09:54:41 +00001313- The module site now treats .pth files not only for path configuration,
1314 but also supports extensions to the initialization code: Lines starting
1315 with import are executed.
1316
Guido van Rossumf61f1662001-01-10 20:13:55 +00001317- There's a new module, warnings, which implements a mechanism for
1318 issuing and filtering warnings. There are some new built-in
1319 exceptions that serve as warning categories, and a new command line
1320 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1321 turns warnings into errors). warnings.warn(message[, category])
1322 issues a warning message; this can also be called from C as
1323 PyErr_Warn(category, message).
1324
1325- A new module xreadlines was added. This exports a single factory
1326 function, xreadlines(). The intention is that this code is the
1327 absolutely fastest way to iterate over all lines in an open
1328 file(-like) object:
1329
1330 import xreadlines
1331 for line in xreadlines.xreadlines(file):
1332 ...do something to line...
1333
1334 This is equivalent to the previous the speed record holder using
1335 file.readlines(sizehint). Note that if file is a real file object
1336 (as opposed to a file-like object), this is equivalent:
1337
1338 for line in file.xreadlines():
1339 ...do something to line...
1340
Tim Peters36cdad12000-12-29 02:06:45 +00001341- The bisect module has new functions bisect_left, insort_left,
1342 bisect_right and insort_right. The old names bisect and insort
1343 are now aliases for bisect_right and insort_right. XXX_right
1344 and XXX_left methods differ in what happens when the new element
1345 compares equal to one or more elements already in the list: the
1346 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001347 right. Code that doesn't care where equal elements end up should
1348 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001349
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001350- The new curses.panel module wraps the panel library that forms part
1351 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1352
Guido van Rossumf61f1662001-01-10 20:13:55 +00001353- The SocketServer module now sets the allow_reuse_address flag by
1354 default in the TCPServer class.
1355
1356- A new function, sys._getframe(), returns the stack frame pointer of
1357 the caller. This is intended only as a building block for
1358 higher-level mechanisms such as string interpolation.
1359
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001360- The pyexpat module supports a number of new handlers, which are
1361 available only in expat 1.2. If invocation of a callback fails, it
1362 will report an additional frame in the traceback. Parser objects
1363 participate now in garbage collection. If expat reports an unknown
1364 encoding, pyexpat will try to use a Python codec; that works only
1365 for single-byte charsets. The parser type objects is exposed as
1366 XMLParserObject.
1367
1368- xml.dom now offers standard definitions for symbolic node type and
1369 exception code constants, and a hierarchy of DOM exceptions. minidom
1370 was adjusted to use them.
1371
1372- The conformance of xml.dom.minidom to the DOM specification was
1373 improved. It detects a number of additional error cases; the
1374 previous/next relationship works even when the tree is modified;
1375 Node supports the normalize() method; NamedNodeMap, DocumentType and
1376 DOMImplementation classes were added; Element supports the
1377 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1378 method.
1379
Guido van Rossumf61f1662001-01-10 20:13:55 +00001380Build issues
1381
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001382- For Unix (and Unix-compatible) builds, configuration and building of
1383 extension modules is now greatly automated. Rather than having to
1384 edit the Modules/Setup file to indicate which modules should be
1385 built and where their include files and libraries are, a
1386 distutils-based setup.py script now takes care of building most
1387 extension modules. All extension modules built this way are built
1388 as shared libraries. Only a few modules that must be linked
1389 statically are still listed in the Setup file; you won't need to
1390 edit their configuration.
1391
1392- Python should now build out of the box on Cygwin. If it doesn't,
1393 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001394
1395- Python now always uses its own (renamed) implementation of getopt()
1396 -- there's too much variation among C library getopt()
1397 implementations.
1398
1399- C++ compilers are better supported; the CXX macro is always set to a
1400 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001401
Tim Petersd92dfe02000-12-12 01:18:41 +00001402Windows changes
1403
1404- select module: By default under Windows, a select() call
1405 can specify no more than 64 sockets. Python now boosts
1406 this Microsoft default to 512. If you need even more than
1407 that, see the MS docs (you'll need to #define FD_SETSIZE
1408 and recompile Python from source).
1409
Guido van Rossumf61f1662001-01-10 20:13:55 +00001410- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1411 subdirectory is no more!
1412
Tim Petersa3a3a032000-11-30 05:22:44 +00001413
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001414What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001415=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001416
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001417Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001418changes are in the file HISTORY. If you are making the jump directly
1419from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1420HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001421
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001422Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1423the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1424http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001425
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001426--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001427
1428======================================================================
1429
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001430What's new in 2.0 (since release candidate 1)?
1431==============================================
1432
1433Standard library
1434
1435- The copy_reg module was modified to clarify its intended use: to
1436 register pickle support for extension types, not for classes.
1437 pickle() will raise a TypeError if it is passed a class.
1438
1439- Fixed a bug in gettext's "normalize and expand" code that prevented
1440 it from finding an existing .mo file.
1441
1442- Restored support for HTTP/0.9 servers in httplib.
1443
Tim Peters989b7b92000-10-16 20:24:53 +00001444- The math module was changed to stop raising OverflowError in case of
1445 underflow, and return 0 instead in underflow cases. Whether Python
1446 used to raise OverflowError in case of underflow was platform-
1447 dependent (it did when the platform math library set errno to ERANGE
1448 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001449
1450- Fixed a bug in StringIO that occurred when the file position was not
1451 at the end of the file and write() was called with enough data to
1452 extend past the end of the file.
1453
1454- Fixed a bug that caused Tkinter error messages to get lost on
1455 Windows. The bug was fixed by replacing direct use of
1456 interp->result with Tcl_GetStringResult(interp).
1457
1458- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1459 redirect response.
1460
1461- Several changes were made to distutils: Some debugging code was
1462 removed from util. Fixed the installer used when an external zip
1463 program (like WinZip) is not found; the source code for this
1464 installer is in Misc/distutils. check_lib() was modified to behave
1465 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1466 test for whether installed modules are on sys.path was changed to
1467 use both normcase() and normpath().
1468
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001469- Several minor bugs were fixed in the xml package (the minidom,
1470 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001471
1472- The regression test driver (regrtest.py) behavior when invoked with
1473 -l changed: It now reports a count of objects that are recognized as
1474 garbage but not freed by the garbage collector.
1475
Tim Peters989b7b92000-10-16 20:24:53 +00001476- The regression test for the math module was changed to test
1477 exceptional behavior when the test is run in verbose mode. Python
1478 cannot yet guarantee consistent exception behavior across platforms,
1479 so the exception part of test_math is run only in verbose mode, and
1480 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001481
1482Internals
1483
1484- PyOS_CheckStack() has been disabled on Win64, where it caused
1485 test_sre to fail.
1486
1487Build issues
1488
1489- Changed compiler flags, so that gcc is always invoked with -Wall and
1490 -Wstrict-prototypes. Users compiling Python with GCC should see
1491 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001492 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001493 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001494
Tim Petersa3a3a032000-11-30 05:22:44 +00001495- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001496
1497Tools and other miscellany
1498
1499- The compiler in Tools/compiler was updated to support the new
1500 language features introduced in 2.0: extended print statement, list
1501 comprehensions, and augmented assignments. The new compiler should
1502 also be backwards compatible with Python 1.5.2; the compiler will
1503 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001504 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001505
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001506What's new in 2.0 release candidate 1 (since beta 2)?
1507=====================================================
1508
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001509What is release candidate 1?
1510
1511We believe that release candidate 1 will fix all known bugs that we
1512intend to fix for the 2.0 final release. This release should be a bit
1513more stable than the previous betas. We would like to see even more
1514widespread testing before the final release, so we are producing this
1515release candidate. The final release will be exactly the same unless
1516any show-stopping (or brown bag) bugs are found by testers of the
1517release candidate.
1518
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001519All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001520to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001521
1522Core language, builtins, and interpreter
1523
1524- A bug that caused crashes when __coerce__ was used with augmented
1525 assignment, e.g. +=, was fixed.
1526
1527- Raise ZeroDivisionError when raising zero to a negative number,
1528 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1529 power operator and the result of math.pow(0.0, -2.0) will vary by
1530 platform. On Linux, it raises a ValueError.
1531
1532- A bug in Unicode string interpolation was fixed that occasionally
1533 caused errors with formats including "%%". For example, the
1534 following expression "%% %s" % u"abc" no longer raises a TypeError.
1535
1536- Compilation of deeply nested expressions raises MemoryError instead
1537 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1538
1539- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1540 rendering them useless. They are now written in binary mode again.
1541
1542Standard library
1543
1544- Keyword arguments are now accepted for most pattern and match object
1545 methods in SRE, the standard regular expression engine.
1546
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001547- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001548 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001549
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001550- Several bugs in the Unicode handling and error handling in _tkinter
1551 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001552
1553- Fix memory management errors in Merge() and Tkapp_Call() routines.
1554
1555- Several changes were made to cStringIO to make it compatible with
1556 the file-like object interface and with StringIO. If operations are
1557 performed on a closed object, an exception is raised. The truncate
1558 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001559 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001560
1561- There were many changes made to the linuxaudiodev module and its
1562 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001563 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001564
1565 Note that this module is named poorly, because it should work
1566 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001567 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001568
1569 The module now raises exceptions when errors occur instead of
1570 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1571 audio) and defines a getptr() method that calls the
1572 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1573
1574- The library_version attribute, introduced in an earlier beta, was
1575 removed because it can not be supported with early versions of the C
1576 readline library, which provides no way to determine the version at
1577 compile-time.
1578
1579- The binascii module is now enabled on Win64.
1580
Tim Peters46446d62000-10-09 21:19:31 +00001581- tokenize.py no longer suffers "recursion depth" errors when parsing
1582 programs with very long string literals.
1583
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001584Internals
1585
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001586- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001587 which is called when the interpreter starts up to determine where
1588 the standard library is installed. These vulnerabilities affect all
1589 previous versions of Python and can be exploited by setting very
1590 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1591 setuid Python script, although use of the wrapper in
1592 Misc/setuid-prog.c will eliminate the vulnerability.
1593
1594- Fixed garbage collection bugs in instance creation that were
1595 triggered when errors occurred during initialization. The solution,
1596 applied in cPickle and in PyInstance_New(), is to call
1597 PyObject_GC_Init() after the initialization of the object's
1598 container attributes is complete.
1599
1600- pyexpat adds definitions of PyModule_AddStringConstant and
1601 PyModule_AddObject if the Python version is less than 2.0, which
1602 provides compatibility with PyXML on Python 1.5.2.
1603
1604- If the platform has a bogus definition for LONG_BIT (the number of
1605 bits in a long), an error will be reported at compile time.
1606
1607- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1608 collection crashes and possibly other, unreported crashes.
1609
1610- Fixed a memory leak in _PyUnicode_Fini().
1611
1612Build issues
1613
1614- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001615 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001616 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001617
1618- The mmap.PAGESIZE constant is now initialized using sysconf when
1619 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1620
1621- The md5 file should now compile on all platforms.
1622
1623- The select module now compiles on platforms that do not define
1624 POLLRDNORM and related constants.
1625
1626- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001627 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001628
Jeremy Hylton10921202000-10-09 18:34:12 +00001629- BeOS: A number of changes were made to the build and installation
1630 process. ar-fake now operates on a directory of object files.
1631 dl_export.h is gone, and its macros now appear on the mwcc command
1632 line during build on PPC BeOS.
1633
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001634- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001635 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001636
1637- Cygwin: Support for shared libraries, Tkinter, and sockets.
1638
1639- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1640
1641Tools and other miscellany
1642
1643- Removed debugging prints from main used with freeze.
1644
Tim Peters46446d62000-10-09 21:19:31 +00001645- IDLE auto-indent no longer crashes when it encounters Unicode
1646 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001647
1648What's new in 2.0 beta 2 (since beta 1)?
1649========================================
1650
1651Core language, builtins, and interpreter
1652
Tim Peters482c0212000-09-26 06:33:09 +00001653- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001654 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001655
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001656- Add -h and -V command line options to print the usage message and
1657 Python version number and exit immediately.
1658
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001659- eval() and exec accept Unicode objects as code parameters.
1660
1661- getattr() and setattr() now also accept Unicode objects for the
1662 attribute name, which are converted to strings using the default
1663 encoding before lookup.
1664
1665- Multiplication on string and Unicode now does proper bounds
1666 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1667 string is too long."
1668
1669- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001670 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001671
Jeremy Hylton1b618592000-09-26 05:32:36 +00001672
1673Standard library and extensions
1674
Guido van Rossum5b08f132001-04-16 02:05:23 +00001675- socket module: the OpenSSL code now adds support for RAND_status()
1676 and EGD (Entropy Gathering Device).
1677
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001678- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001679 argument checking; it still takes no arguments.
1680
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001681- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001682
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001683- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001684
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001685- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001686
1687- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001688 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001689
1690- copy: Copy Unicode objects atomically.
1691
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001692- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001693
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001694- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001695
Fred Drake67233bc2000-09-26 16:40:27 +00001696- dbm: Add get() and setdefault() methods to dbm object. Add constant
1697 `library' to module that names the library used. Added doc strings
1698 and method names to error messages. Uses configure to determine
1699 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1700 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001701
1702- distutils: Update to version 0.9.3.
1703
1704- dl: Add several dl.RTLD_ constants.
1705
1706- fpectl: Now supported on FreeBSD.
1707
1708- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1709 found by the collector will be saved in gc.garbage. This is useful
1710 for debugging a program that creates reference cycles.
1711
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001712- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001713 of HTTP class. Do not close socket on zero-length response. Do not
1714 crash when server sends invalid content-length header.
1715
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001716- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001717
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001718- marshal: When reading a short, sign-extend on platforms where shorts
1719 are bigger than 16 bits. When reading a long, repair the unportable
1720 sign extension that was being done for 64-bit machines. (It assumed
1721 that signed right shift sign-extends.)
1722
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001723- operator: Add contains(), invert(), __invert__() as aliases for
1724 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001725
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001726- os: Add support for popen2() and popen3() on all platforms where
1727 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001728
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001729- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001730 clicking on a file in Explorer (or passing the file name to the
1731 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001732
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001733- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001734 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001735
1736- pickle: Now raises ValueError when an invalid pickle that contains
1737 a non-string repr where a string repr was expected. This behavior
1738 matches cPickle.
1739
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001740- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001741
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001742- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001743
1744- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001745 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001746 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001747
1748- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001749 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001750
1751- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001752 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001753 few cycles during startup since the first call to
1754 setdefaultencoding() will initialize the codec registry and the
1755 encodings package.
1756
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001757- socket: Support for size hint in readlines() method of object returned
1758 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001759
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001760- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001761 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001762 is followed by whitespace.
1763
Tim Petersa3a3a032000-11-30 05:22:44 +00001764- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001765
1766- struct: Check ranges for bytes and shorts.
1767
1768- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001769 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001770
1771- Tkinter: Image objects are now guaranteed to have unique ids. Set
1772 event.delta to zero if Tk version doesn't support mousewheel.
1773 Removed some debugging prints.
1774
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001775- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001776
Fred Drake67233bc2000-09-26 16:40:27 +00001777- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001778 which works around a bug in Norton AntiVirus 2000 that leads directly
1779 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001780
1781- xml: New version detection code allows PyXML to override standard
1782 XML package if PyXML version is greater than 0.6.1.
1783
Fred Drake64bb3802000-09-26 16:21:35 +00001784- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1785 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1786 tree only for nodes which are sufficiently interesting to a specific
1787 application. Does not provide the HTML-specific extensions. Still
1788 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001789
Fred Drake64bb3802000-09-26 16:21:35 +00001790- xml.sax: SAX 2 support for Python, including all the handler
1791 interfaces needed to process XML 1.0 compliant XML. Some
1792 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001793
Fred Drake64bb3802000-09-26 16:21:35 +00001794- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1795 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001796
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001797
Jeremy Hylton1b618592000-09-26 05:32:36 +00001798C API
1799
1800- Add three new convenience functions for module initialization --
1801 PyModule_AddObject(), PyModule_AddIntConstant(), and
1802 PyModule_AddStringConstant().
1803
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001804- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001805 removed and add #error to Python.h if NULL isn't defined after
1806 #include of stdio.h.
1807
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001808- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001809 backwards compatibility (at the source level) with old extensions.
1810
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001811- A wrapper API was added for signal() and sigaction(). Instead of
1812 either function, always use PyOS_getsig() to get a signal handler
1813 and PyOS_setsig() to set one. A new convenience typedef
1814 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001815
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001816- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001817 internal data buffer and size of a string object -- or the default
1818 encoded version of a Unicode object.
1819
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001820- PyString_Size() and PyString_AsString() accept Unicode objects.
1821
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001822- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001823 exists). INT_MAX and LONG_MAX will always be defined, even if
1824 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001825
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001826- PyFloat_FromString takes a second argument, pend, that was
1827 effectively useless. It is now officially useless but preserved for
1828 backwards compatibility. If the pend argument is not NULL, *pend is
1829 set to NULL.
1830
1831- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1832 for the attribute name. See note on getattr() above.
1833
1834- A few bug fixes to argument processing for Unicode.
1835 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1836 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1837 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001838 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001839
1840- Py_BuildValue accepts B format (for bgen-generated code).
1841
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001842
Jeremy Hylton1b618592000-09-26 05:32:36 +00001843Internals
1844
1845- On Unix, fix code for finding Python installation directory so that
1846 it works when argv[0] is a relative path.
1847
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001848- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001849 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001850 rather than by generating a copy of the object.
1851
Tim Peters482c0212000-09-26 06:33:09 +00001852- Several of the internal Unicode tables are much smaller now, and
1853 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001854
Jeremy Hylton97693b02000-09-26 17:42:51 +00001855- In the garbage collector: Fixed bug in collection of tuples. Fixed
1856 bug that caused some instances to be removed from the container set
1857 while they were still live. Fixed parsing in gc.set_debug() for
1858 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001859
1860- Fixed refcount problem in instance deallocation that only occurred
1861 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1862
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001863- On Windows, getpythonregpath is now protected against null data in
1864 registry key.
1865
1866- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001867 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001868
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001869
Jeremy Hylton1b618592000-09-26 05:32:36 +00001870Build and platform-specific issues
1871
1872- Better support of GNU Pth via --with-pth configure option.
1873
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001874- Python/C API now properly exposed to dynamically-loaded extension
1875 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001876
1877- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1878 Don't define MS_SYNC to be zero when it is undefined. Added missing
1879 prototypes in posixmodule.c.
1880
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001881- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001882 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001883
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001884- Fix largefile support on older NetBSD systems and OpenBSD by adding
1885 define for TELL64.
1886
1887
1888Tools and other miscellany
1889
1890- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1891
1892- freeze: The modulefinder now works with 2.0 opcodes.
1893
Tim Petersa3a3a032000-11-30 05:22:44 +00001894- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001895 Move hackery of sys.argv until after the Tk instance has been
1896 created, which allows the application-specific Tkinter
1897 initialization to be executed if present; also pass an explicit
1898 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001899
Jeremy Hylton1b618592000-09-26 05:32:36 +00001900
1901What's new in 2.0 beta 1?
1902=========================
1903
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001904Source Incompatibilities
1905------------------------
1906
1907None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1908such as single-argument append(), connect() and bind(), and changes to
1909str(long) and repr(float).
1910
1911
1912Binary Incompatibilities
1913------------------------
1914
1915- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1916with Python 2.0; these extensions will have to be rebuilt for Python
19172.0.
1918
1919- On Windows, attempting to import a third party extension built for
1920Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1921can do about this. Check your PYTHONPATH environment variable!
1922
1923- Python bytecode files (*.pyc and *.pyo) are not compatible between
1924releases.
1925
1926
1927Overview of Changes Since 1.6
1928-----------------------------
1929
1930There are many new modules (including brand new XML support through
1931the xml package, and i18n support through the gettext module); a list
1932of all new modules is included below. Lots of bugs have been fixed.
1933
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001934The process for making major new changes to the language has changed
1935since Python 1.6. Enhancements must now be documented by a Python
1936Enhancement Proposal (PEP) before they can be accepted.
1937
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001938There are several important syntax enhancements, described in more
1939detail below:
1940
1941 - Augmented assignment, e.g. x += 1
1942
1943 - List comprehensions, e.g. [x**2 for x in range(10)]
1944
1945 - Extended import statement, e.g. import Module as Name
1946
1947 - Extended print statement, e.g. print >> file, "Hello"
1948
1949Other important changes:
1950
1951 - Optional collection of cyclical garbage
1952
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001953Python Enhancement Proposal (PEP)
1954---------------------------------
1955
1956PEP stands for Python Enhancement Proposal. A PEP is a design
1957document providing information to the Python community, or describing
1958a new feature for Python. The PEP should provide a concise technical
1959specification of the feature and a rationale for the feature.
1960
1961We intend PEPs to be the primary mechanisms for proposing new
1962features, for collecting community input on an issue, and for
1963documenting the design decisions that have gone into Python. The PEP
1964author is responsible for building consensus within the community and
1965documenting dissenting opinions.
1966
1967The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001968
1969Augmented Assignment
1970--------------------
1971
1972This must have been the most-requested feature of the past years!
1973Eleven new assignment operators were added:
1974
Guido van Rossume905e952000-09-05 12:42:46 +00001975 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001976
1977For example,
1978
1979 A += B
1980
1981is similar to
1982
1983 A = A + B
1984
1985except that A is evaluated only once (relevant when A is something
1986like dict[index].attr).
1987
1988However, if A is a mutable object, A may be modified in place. Thus,
1989if A is a number or a string, A += B has the same effect as A = A+B
1990(except A is only evaluated once); but if a is a list, A += B has the
1991same effect as A.extend(B)!
1992
1993Classes and built-in object types can override the new operators in
1994order to implement the in-place behavior; the not-in-place behavior is
1995used automatically as a fallback when an object doesn't implement the
1996in-place behavior. For classes, the method name is derived from the
1997method name for the corresponding not-in-place operator by inserting
1998an 'i' in front of the name, e.g. __iadd__ implements in-place
1999__add__.
2000
2001Augmented assignment was implemented by Thomas Wouters.
2002
2003
2004List Comprehensions
2005-------------------
2006
2007This is a flexible new notation for lists whose elements are computed
2008from another list (or lists). The simplest form is:
2009
2010 [<expression> for <variable> in <sequence>]
2011
Guido van Rossum56db0952000-09-06 23:34:25 +00002012For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002013This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002014
2015You can also add a condition:
2016
2017 [<expression> for <variable> in <sequence> if <condition>]
2018
2019For example, [w for w in words if w == w.lower()] would yield the list
2020of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002021than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002022
2023You can also have nested for loops and more than one 'if' clause. For
2024example, here's a function that flattens a sequence of sequences::
2025
2026 def flatten(seq):
2027 return [x for subseq in seq for x in subseq]
2028
2029 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2030
2031This prints
2032
2033 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2034
2035List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002036Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002037
2038
2039Extended Import Statement
2040-------------------------
2041
2042Many people have asked for a way to import a module under a different
2043name. This can be accomplished like this:
2044
2045 import foo
2046 bar = foo
2047 del foo
2048
2049but this common idiom gets old quickly. A simple extension of the
2050import statement now allows this to be written as follows:
2051
2052 import foo as bar
2053
2054There's also a variant for 'from ... import':
2055
2056 from foo import bar as spam
2057
2058This also works with packages; e.g. you can write this:
2059
2060 import test.regrtest as regrtest
2061
2062Note that 'as' is not a new keyword -- it is recognized only in this
2063context (this is only possible because the syntax for the import
2064statement doesn't involve expressions).
2065
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002066Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002067
2068
2069Extended Print Statement
2070------------------------
2071
2072Easily the most controversial new feature, this extension to the print
2073statement adds an option to make the output go to a different file
2074than the default sys.stdout.
2075
2076For example, to write an error message to sys.stderr, you can now
2077write:
2078
2079 print >> sys.stderr, "Error: bad dog!"
2080
2081As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002082evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002083
2084 print >> None, "Hello world"
2085
2086is equivalent to
2087
2088 print "Hello world"
2089
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002090Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002091
2092
2093Optional Collection of Cyclical Garbage
2094---------------------------------------
2095
2096Python is now equipped with a garbage collector that can hunt down
2097cyclical references between Python objects. It's no replacement for
2098reference counting; in fact, it depends on the reference counts being
2099correct, and decides that a set of objects belong to a cycle if all
2100their reference counts can be accounted for from their references to
2101each other. This devious scheme was first proposed by Eric Tiedemann,
2102and brought to implementation by Neil Schemenauer.
2103
2104There's a module "gc" that lets you control some parameters of the
2105garbage collection. There's also an option to the configure script
2106that lets you enable or disable the garbage collection. In 2.0b1,
2107it's on by default, so that we (hopefully) can collect decent user
2108experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002109performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002110off by default in the final 2.0 release.
2111
2112
2113Smaller Changes
2114---------------
2115
2116A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2117map(None, seq1, seq2, ...) when the sequences have the same length;
2118i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2119the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002120zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002121
2122sys.version_info is a tuple (major, minor, micro, level, serial).
2123
2124Dictionaries have an odd new method, setdefault(key, default).
2125dict.setdefault(key, default) returns dict[key] if it exists; if not,
2126it sets dict[key] to default and returns that value. Thus:
2127
2128 dict.setdefault(key, []).append(item)
2129
2130does the same work as this common idiom:
2131
2132 if not dict.has_key(key):
2133 dict[key] = []
2134 dict[key].append(item)
2135
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002136There are two new variants of SyntaxError that are raised for
2137indentation-related errors: IndentationError and TabError.
2138
2139Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2140escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002141
2142The limits on the size of expressions and file in Python source code
2143have been raised from 2**16 to 2**32. Previous versions of Python
2144were limited because the maximum argument size the Python VM accepted
2145was 2**16. This limited the size of object constructor expressions,
2146e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2147limit was raised thanks to a patch by Charles Waldman that effectively
2148fixes the problem. It is now much more likely that you will be
2149limited by available memory than by an arbitrary limit in Python.
2150
2151The interpreter's maximum recursion depth can be modified by Python
2152programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2153limit is the maximum number of recursive calls that can be made by
2154Python code. The limit exists to prevent infinite recursion from
2155overflowing the C stack and causing a core dump. The default value is
21561000. The maximum safe value for a particular platform can be found
2157by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002158
2159New Modules and Packages
2160------------------------
2161
2162atexit - for registering functions to be called when Python exits.
2163
2164imputil - Greg Stein's alternative API for writing custom import
2165hooks.
2166
2167pyexpat - an interface to the Expat XML parser, contributed by Paul
2168Prescod.
2169
2170xml - a new package with XML support code organized (so far) in three
2171subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2172would fill a volume. There's a special feature whereby a
2173user-installed package named _xmlplus overrides the standard
2174xmlpackage; this is intended to give the XML SIG a hook to distribute
2175backwards-compatible updates to the standard xml package.
2176
2177webbrowser - a platform-independent API to launch a web browser.
2178
2179
Guido van Rossume905e952000-09-05 12:42:46 +00002180Changed Modules
2181---------------
2182
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002183array -- new methods for array objects: count, extend, index, pop, and
2184remove
2185
2186binascii -- new functions b2a_hex and a2b_hex that convert between
2187binary data and its hex representation
2188
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002189calendar -- Many new functions that support features including control
2190over which day of the week is the first day, returning strings instead
2191of printing them. Also new symbolic constants for days of week,
2192e.g. MONDAY, ..., SUNDAY.
2193
2194cgi -- FieldStorage objects have a getvalue method that works like a
2195dictionary's get method and returns the value attribute of the object.
2196
2197ConfigParser -- The parser object has new methods has_option,
2198remove_section, remove_option, set, and write. They allow the module
2199to be used for writing config files as well as reading them.
2200
2201ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002202optionally support the RFC 959 REST command.
2203
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002204gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002205
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002206httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2207the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002208
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002209locale -- implement getdefaultlocale for Win32 and Macintosh
2210
2211marshal -- no longer dumps core when marshaling deeply nested or
2212recursive data structures
2213
2214os -- new functions isatty, seteuid, setegid, setreuid, setregid
2215
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002216os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2217support under Unix.
2218
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002219os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002220
2221os.path -- fix semantics of os.path.commonprefix
2222
2223smtplib -- support for sending very long messages
2224
2225socket -- new function getfqdn()
2226
2227readline -- new functions to read, write and truncate history files.
2228The readline section of the library reference manual contains an
2229example.
2230
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002231select -- add interface to poll system call
2232
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002233shutil -- new copyfileobj function
2234
2235SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2236HTTP server.
2237
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002238Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002239
2240urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002241e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002242
2243whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002244
2245
2246Obsolete Modules
2247----------------
2248
2249None. However note that 1.6 made a whole slew of modules obsolete:
2250stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2251poly, zmod, strop, util, whatsound.
2252
2253
2254Changed, New, Obsolete Tools
2255----------------------------
2256
Tim Peters8b092332000-09-05 20:15:25 +00002257None.
Guido van Rossume905e952000-09-05 12:42:46 +00002258
2259
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002260C-level Changes
2261---------------
2262
2263Several cleanup jobs were carried out throughout the source code.
2264
2265All C code was converted to ANSI C; we got rid of all uses of the
2266Py_PROTO() macro, which makes the header files a lot more readable.
2267
2268Most of the portability hacks were moved to a new header file,
2269pyport.h; several other new header files were added and some old
2270header files were removed, in an attempt to create a more rational set
2271of header files. (Few of these ever need to be included explicitly;
2272they are all included by Python.h.)
2273
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002274Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002275and Win64, especially for the new Intel Itanium processor. Mick also
2276added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002277
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002278The C APIs to return an object's size have been update to consistently
2279use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2280previous versions, the abstract interfaces used PyXXX_Length and the
2281concrete interfaces used PyXXX_Size. The old names,
2282e.g. PyObject_Length, are still available for backwards compatibility
2283at the API level, but are deprecated.
2284
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002285The PyOS_CheckStack function has been implemented on Windows by
2286Fredrik Lundh. It prevents Python from failing with a stack overflow
2287on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002288
2289The GC changes resulted in creation of two new slots on object,
2290tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002291the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002292
2293The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002294C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002295
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002296PyErr_Format has been updated to automatically calculate the size of
2297the buffer needed to hold the formatted result string. This change
2298prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002299
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002300New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002301
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002302PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2303that are the same as their non-Ex counterparts except they take an
2304extra flag argument that tells them to close the file when done.
2305
2306XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002307
Tim Peters8b092332000-09-05 20:15:25 +00002308
2309Windows Changes
2310---------------
2311
2312New popen2/popen3/peopen4 in os module (see Changed Modules above).
2313
2314os.popen is much more usable on Windows 95 and 98. See Microsoft
2315Knowledge Base article Q150956. The Win9x workaround described there
2316is implemented by the new w9xpopen.exe helper in the root of your
2317Python installation. Note that Python uses this internally; it is not
2318a standalone program.
2319
2320Administrator privileges are no longer required to install Python
2321on Windows NT or Windows 2000. If you have administrator privileges,
2322Python's registry info will be written under HKEY_LOCAL_MACHINE.
2323Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002324under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002325uses of Python, but will prevent some advanced uses from working
2326(for example, running a Python script as an NT service, or possibly
2327from CGI).
2328
2329[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2330installer; instead, it installs the needed Tcl/Tk files directly in the
2331Python directory. If you already have a Tcl/Tk installation, this
2332wastes some disk space (about 4 Megs) but avoids problems with
2333conflicting Tcl/Tk installations, and makes it much easier for Python
2334to ensure that Tcl/Tk can find all its files.
2335
2336[This was new in 1.6] The Windows installer now installs by default in
2337\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2338
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002339
2340Updates to the changes between 1.5.2 and 1.6
2341--------------------------------------------
2342
2343The 1.6 NEWS file can't be changed after the release is done, so here
2344is some late-breaking news:
2345
2346New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2347and changes to getlocale() and setlocale().
2348
2349The new module is now enabled per default.
2350
2351It is not true that the encodings codecs cannot be used for normal
2352strings: the string.encode() (which is also present on 8-bit strings
2353!) allows using them for 8-bit strings too, e.g. to convert files from
2354cp1252 (Windows) to latin-1 or vice-versa.
2355
2356Japanese codecs are available from Tamito KAJIYAMA:
2357http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2358
2359
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002360======================================================================