blob: 50ec64f581315e643c42d6129ee63da9f26e3c91 [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
Guido van Rossum61c345f2001-09-04 03:26:15 +000040 values are -Qold, -Qwarn, and -Qnew. The default is -Qold, meaning
Guido van Rossumae457142001-08-31 18:31:35 +000041 the / operator has its classic meaning and no warnings are issued.
Guido van Rossum61c345f2001-09-04 03:26:15 +000042 Using -Qwarn issues a run-time warning about all uses of classic
43 division for int, long, float and complex arguments. Using -Qnew is
Guido van Rossumae457142001-08-31 18:31:35 +000044 questionable; it turns on new division by default, but only in the
Guido van Rossum61c345f2001-09-04 03:26:15 +000045 __main__ module. You can usefully combine -Qwarn and -Qnew: this
Guido van Rossumae457142001-08-31 18:31:35 +000046 gives the __main__ module new division, and warns about classic
47 division everywhere else.
48
Tim Petersbdee63f2001-09-02 03:40:59 +000049- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +000050 long, float, str, unicode, and tuple. (The types complex, list and
51 dictionary can also be subclassed; this was introduced earlier.)
52 Note that restrictions apply when subclassing immutable built-in
53 types: you can only affect the value of the instance by overloading
54 __new__. You can add mutable attributes, and the subclass instances
55 will have a __dict__ attribute, but you cannot change the "value"
56 (as implemented by the base class) of an immutable subclass instance
57 once it is created.
58
Guido van Rossumaaf80c82001-09-02 13:44:35 +000059- The dictionary constructor now takes an optional argument, a
60 mapping-like object, and initializes the dictionary from its
61 (key, value) pairs.
62
Tim Petersbdee63f2001-09-02 03:40:59 +000063- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +000064 "cooperative super calls" in a multiple inheritance setting. For an
65 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
66
Tim Petersbdee63f2001-09-02 03:40:59 +000067- A new built-in type, getset, has been added. This enables the
Guido van Rossumae457142001-08-31 18:31:35 +000068 creation of "computed attributes". Such attributes are implemented
69 by getter and setter functions (or only one of these for read-only
70 or write-only attributes), without the need to override
71 __getattr__. See http://www.python.org/2.2/descrintro.html#getset
72
Tim Petersbdee63f2001-09-02 03:40:59 +000073- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +000074 liberalized, to allow leading zeroes. Examples of literals now
75 legal that were SyntaxErrors before:
76
77 00.0 0e3 0100j 07.5 00000000000000000008.
78
Tim Petersbdee63f2001-09-02 03:40:59 +000079- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +000080 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
81
Tim Petersedc99312001-08-22 21:36:50 +000082Library
83
Tim Petersa40c7932001-09-05 22:36:56 +000084- The new C standard no longer requires that math libraries set errno to
85 ERANGE on overflow. For platform libraries that exploit this new
86 freedom, Python's overflow-checking was wholly broken. A new overflow-
87 checking scheme attempts to repair that, but may not be reliable on all
88 platforms (C doesn't seem to provide anything both useful and portable
89 in this area anymore).
90
Martin v. Löwis44f86962001-09-05 13:44:54 +000091- Asynchronous timeout actions are available through the new class
92 threading.Timer.
93
Tim Peters78526162001-09-05 00:53:45 +000094- math.log and math.log10 now return sensible results for even huge
95 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
96
Tim Petersbdee63f2001-09-02 03:40:59 +000097- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +000098 currently held. See the docs for the imp module.
99
Tim Petersbdee63f2001-09-02 03:40:59 +0000100- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000101 dumps containing ints written on platforms where Python ints are 8 bytes.
102 When read on a box where Python ints are 4 bytes, such values are
103 converted to Python longs.
104
Tim Petersbdee63f2001-09-02 03:40:59 +0000105- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000106 code objects is no longer allowed. This plugs a security hole.
107
Tim Petersedc99312001-08-22 21:36:50 +0000108Tools
109
110Build
111
Tim Peters7eea37e2001-09-04 22:08:56 +0000112C API
113
114- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000115
Tim Peters9fffa3e2001-09-04 05:14:19 +0000116- Note that PyLong_AsDouble can fail! This has always been true, but no
117 callers checked for it. It's more likely to fail now, because overflow
118 errors are properly detected now. The proper way to check:
119
120 double x = PyLong_AsDouble(some_long_object);
121 if (x == -1.0 && PyErr_Occurred()) {
122 /* The conversion failed. */
123 }
124
Tim Petersbdee63f2001-09-02 03:40:59 +0000125- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000126 compile but will not participate in GC. To upgrade an extension
127 module:
128
129 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000130
Neil Schemenauer4042c692001-08-30 15:38:01 +0000131 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
132 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000133
Neil Schemenauer4042c692001-08-30 15:38:01 +0000134 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
135 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000136
Neil Schemenauer4042c692001-08-30 15:38:01 +0000137 - remove PyGC_HEAD_SIZE from object size calculations
138
139 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
140
Tim Petersbdee63f2001-09-02 03:40:59 +0000141- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000142 These can be used safely to construct string objects from a
143 sprintf-style format string (similar to the format string supported
144 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000145
Tim Petersedc99312001-08-22 21:36:50 +0000146New platforms
147
Tim Petersb7da0902001-09-02 23:01:43 +0000148- Stephen Hansen contributed patches sufficient to get a clean compile
149 under Borland C (Windows), but he reports problems running it and ran
150 out of time to complete the port. Volunteers? Expect a MemoryError
151 when importing the types module; this is probably shallow, and
152 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000153
Tim Petersedc99312001-08-22 21:36:50 +0000154Tests
155
156Windows
157
Tim Petersbdee63f2001-09-02 03:40:59 +0000158- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000159 points to command.com (patch from Brian Quinlan).
160
Tim Petersedc99312001-08-22 21:36:50 +0000161
Tim Peters20f51a72001-07-21 02:31:40 +0000162What's New in Python 2.2a2?
163===========================
164
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000165Build
166
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000167- Tim Peters developed a brand new Windows installer using Wise 8.1,
168 generously donated to us by Wise Solutions.
169
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000170- configure supports a new option --enable-unicode, with the values
171 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
172 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000173
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000174- A new configure option --enable-framework builds a Mac OS X framework,
175 which "make frameworkinstall" will install. This provides a starting
176 point for more mac-like functionality, join pythonmac-sig@python.org
177 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000178
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000179- The NeXT platform is no longer supported.
180
181- The `new' module is now statically linked.
182
Tim Peters0afb6092001-08-15 06:06:44 +0000183Tools
184
185- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000186 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000187 the module docstring for details.
188
Tim Peters20f51a72001-07-21 02:31:40 +0000189Tests
190
Tim Peters5e824c32001-08-12 22:25:01 +0000191- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000192 platforms, allowing to give clearer test result output. regrtest
193 also has optional --use/-u switch to run normally disabled tests
194 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000195
Tim Peters20f51a72001-07-21 02:31:40 +0000196- Several new tests in the standard test suite, with special thanks to
197 Nick Mathewson.
198
199Core
200
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000201- The floor division operator // has been added as outlined in PEP
202 238. The / operator still provides classic division (and will until
203 Python 3.0) unless "from __future__ import division" is included, in
204 which case the / operator will provide true division. The operator
205 module provides truediv() and floordiv() functions. Augmented
206 assignment variants are included, as are the equivalent overloadable
207 methods and C API methods. See the PEP for a full discussion:
208 <http://python.sf.net/peps/pep-0238.html>
209
Tim Peters6cd6a822001-08-17 22:11:27 +0000210- Future statements are now effective in simulated interactive shells
211 (like IDLE). This should "just work" by magic, but read Michael
212 Hudson's "Future statements in simulated shells" PEP 264 for full
213 details: <http://python.sf.net/peps/pep-0264.html>.
214
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000215- The type/class unification (PEP 252-253) was integrated into the
216 trunk and is not so tentative any more (the exact specification of
217 some features is still tentative). A lot of work has done on fixing
218 bugs and adding robustness and features (performance still has to
219 come a long way).
220
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000221- Warnings about a mismatch in the Python API during extension import
222 now use the Python warning framework (which makes it possible to
223 write filters for these warnings).
224
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000225- A function's __dict__ (aka func_dict) will now always be a
226 dictionary. It used to be possible to delete it or set it to None,
227 but now both actions raise TypeErrors. It is still legal to set it
228 to a dictionary object. Getting func.__dict__ before any attributes
229 have been assigned now returns an empty dictionary instead of None.
230
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000231- A new command line option, -E, was added which disables the use of
232 all environment variables, or at least those that are specifically
233 significant to Python. Usually those have a name starting with
234 "PYTHON". This was used to fix a problem where the tests fail if
235 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
236 older distribution.
237
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000238Library
239
Tim Peters5e824c32001-08-12 22:25:01 +0000240- New class Differ and new functions ndiff() and restore() in difflib.py.
241 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000242 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000243
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000244- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
245 value using the minimal quoting required for the value; more
246 reliable than using xml.sax.saxutils.escape() for attribute values.
247
248- Readline completion support for cmd.Cmd was added.
249
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000250- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
251
252- Added function threading.BoundedSemaphore()
253
254- Added Ka-Ping Yee's cgitb.py module.
255
256- The `new' module now exposes the CO_xxx flags.
257
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000258New platforms
259
260C API
261
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000262- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
263 which provide a cross-platform implementations for the
264 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
265 the standard sprintf() and vsprintf() C lib APIs, these versions
266 apply bounds checking on the used buffer which enhances protection
267 against buffer overruns.
268
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000269- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000270 and extensions using different Unicode widths is rendered next to
271 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000272 will result in an ImportError. Unicode extensions writers must make
273 sure to check the Unicode width compatibility in their extensions by
274 using at least one of the mangled Unicode APIs in the extension.
275
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000276- Two new flags METH_NOARGS and METH_O are available in method definition
277 tables to simplify implementation of methods with no arguments and a
278 single untyped argument. Calling such methods is more efficient than
279 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
280 deprecated.
281
Tim Petersc1731372001-08-04 08:12:36 +0000282Windows
283
284- "import module" now compiles module.pyw if it exists and nothing else
285 relevant is found.
286
Tim Peters20f51a72001-07-21 02:31:40 +0000287
Guido van Rossum55a78992001-07-17 17:22:32 +0000288What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000289===========================
290
291Core
Tim Petersa814db52001-05-14 07:05:58 +0000292
Tim Peters6d6c1a32001-08-02 04:15:00 +0000293- TENTATIVELY, a large amount of code implementing much of what's
294 described in PEP 252 (Making Types Look More Like Classes) and PEP
295 253 (Subtyping Built-in Types) was added. This will be released
296 with Python 2.2a1. Documentation will be provided separately
297 through http://www.python.org/2.2/. The purpose of releasing this
298 with Python 2.2a1 is to test backwards compatibility. It is
299 possible, though not likely, that a decision is made not to release
300 this code as part of 2.2 final, if any serious backwards
301 incompapatibilities are found during alpha testing that cannot be
302 repaired.
303
Guido van Rossum55a78992001-07-17 17:22:32 +0000304- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000305 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000306 more 'yield' statements. See PEP 255. Since this adds a new
307 keyword to the language, this feature must be enabled by including a
308 future statement: "from __future__ import generators" (see PEP 236).
309 Generators will become a standard feature in a future release
310 (probably 2.3). Without this future statement, 'yield' remains an
311 ordinary identifier, but a warning is issued each time it is used.
312 (These warnings currently don't conform to the warnings framework of
313 PEP 230; we intend to fix this in 2.2a2.)
314
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000315- The UTF-16 codec was modified to be more RFC compliant. It will now
316 only remove BOM characters at the start of the string and then
317 only if running in native mode (UTF-16-LE and -BE won't remove a
318 leading BMO character).
319
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000320- Strings now have a new method .decode() to complement the already
321 existing .encode() method. These two methods provide direct access
322 to the corresponding decoders and encoders of the registered codecs.
323
324 To enhance the usability of the .encode() method, the special
325 casing of Unicode object return values was dropped (Unicode objects
326 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000327
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000328 Both methods will now return whatever the codec in charge of the
329 requested encoding returns as object, e.g. Unicode codecs will
330 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
331 will return u"äöü"). This enables codec writer to create codecs
332 for various simple to use conversions.
333
334 New codecs were added to demonstrate these new features (the .encode()
335 and .decode() columns indicate the type of the returned objects):
336
337 Name | .encode() | .decode() | Description
338 ----------------------------------------------------------------------
339 uu | string | string | UU codec (e.g. for email)
340 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000341 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000342 zlib | string | string | zlib compression
343 hex | string | string | 2-byte hex codec
344 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
345
Mark Hammond2a0af792001-05-14 03:09:36 +0000346- Some operating systems now support the concept of a default Unicode
347 encoding for file system operations. Notably, Windows supports 'mbcs'
348 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000349 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000350 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000351
352 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000353 functions that return filenames (such as os.listdir()) to return Python
354 string objects pre-encoded using the default file system encoding for
355 the platform. As this encoding is likely to be different from Python's
356 default encoding, converting this name to a Unicode object before passing
357 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000358 would attempt to use its default encoding (generally ASCII) rather than
359 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000360
Tim Petersa814db52001-05-14 07:05:58 +0000361 In general, this change simply removes surprises when working with
362 Unicode and the file system, making these operations work as you expect,
363 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000364 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000365
Tim Peters61dff2b2001-05-08 15:43:37 +0000366- Float (and complex) literals in source code were evaluated to full
367 precision only when running from a .py file; the same code loaded from a
368 .pyc (or .pyo) file could suffer numeric differences starting at about the
369 12th significant decimal digit. For example, on a machine with IEEE-754
370 floating arithmetic,
371
372 x = 9007199254740992.0
373 print long(x)
374
375 printed 9007199254740992 if run directly from .py, but 9007199254740000
376 if from a compiled (.pyc or .pyo) file. This was due to marshal using
377 str(float) instead of repr(float) when building code objects. marshal
378 now uses repr(float) instead, which should reproduce floats to full
379 machine precision (assuming the platform C float<->string I/O conversion
380 functions are of good quality).
381
382 This may cause floating-point results to change in some cases, and
383 usually for the better, but may also cause numerically unstable
384 algorithms to break.
385
Tim Peters2f228e72001-05-13 00:19:31 +0000386- The implementation of dicts suffers fewer collisions, which has speed
387 benefits. However, the order in which dict entries appear in dict.keys(),
388 dict.values() and dict.items() may differ from previous releases for a
389 given dict. Nothing is defined about this order, so no program should
390 rely on it. Nevertheless, it's easy to write test cases that rely on the
391 order by accident, typically because of printing the str() or repr() of a
392 dict to an "expected results" file. See Lib/test/test_support.py's new
393 sortdict(dict) function for a simple way to display a dict in sorted
394 order.
395
Tim Peters7a3bfc32001-06-12 01:22:22 +0000396- Many other small changes to dicts were made, resulting in faster
397 operation along the most common code paths.
398
Guido van Rossum10315822001-05-01 20:54:30 +0000399- Dictionary objects now support the "in" operator: "x in dict" means
400 the same as dict.has_key(x).
401
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000402- The update() method of dictionaries now accepts generic mapping
403 objects. Specifically the argument object must support the .keys()
404 and __getitem__() methods. This allows you to say, for example,
405 {}.update(UserDict())
406
Guido van Rossum10315822001-05-01 20:54:30 +0000407- Iterators were added; this is a generalized way of providing values
408 to a for loop. See PEP 234. There's a new built-in function iter()
409 to return an iterator. There's a new protocol to get the next value
410 from an iterator using the next() method (in Python) or the
411 tp_iternext slot (in C). There's a new protocol to get iterators
412 using the __iter__() method (in Python) or the tp_iter slot (in C).
413 Iterating (i.e. a for loop) over a dictionary generates its keys.
414 Iterating over a file generates its lines.
415
Tim Petersf553f892001-05-01 20:45:31 +0000416- The following functions were generalized to work nicely with iterator
417 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000418 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000419 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
420 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000421 join() method of strings
422 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000423 'x in y' and 'x not in y' (PySequence_Contains() in C API)
424 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000425 right-hand side of assignment statements with multiple targets, such as
426 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000427
Tim Petersd85e1022001-05-11 21:51:48 +0000428- Accessing module attributes is significantly faster (for example,
429 random.random or os.path or yourPythonModule.yourAttribute).
430
Tim Peterse63415e2001-05-08 04:38:29 +0000431- Comparing dictionary objects via == and != is faster, and now works even
432 if the keys and values don't support comparisons other than ==.
433
Tim Peters95bf9392001-05-10 08:32:44 +0000434- Comparing dictionaries in ways other than == and != is slower: there were
435 insecurities in the dict comparison implementation that could cause Python
436 to crash if the element comparison routines for the dict keys and/or
437 values mutated the dicts. Making the code bulletproof slowed it down.
438
Tim Peterseb28ef22001-06-02 05:27:19 +0000439- Collisions in dicts are resolved via a new approach, which can help
440 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000441 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000442 faster now. Thanks to Christian Tismer for pointing out the cause and
443 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000444
Tim Peters52e155e2001-06-16 05:42:57 +0000445- repr() is much faster for large containers (dict, list, tuple).
446
447
Tim Petersa814db52001-05-14 07:05:58 +0000448Library
449
Fred Drake960fdf92001-07-20 18:38:26 +0000450- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
451 were added to the string module. These a locale-indenpendent
452 constants, unlike letters, lowercase, and uppercase. These are now
453 use in appropriate locations in the standard library.
454
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000455- The flags used in dlopen calls can now be configured using
456 sys.setdlopenflags and queried using sys.getdlopenflags.
457
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000458- Fredrik Lundh's xmlrpclib is now a standard library module. This
459 provides full client-side XML-RPC support. In addition,
460 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
461 one asyncore-based). Thanks to Eric Raymond for the documentation.
462
Guido van Rossum643d3912001-07-05 14:46:25 +0000463- The xrange() object is simplified: it no longer supports slicing,
464 repetition, comparisons, efficient 'in' checking, the tolist()
465 method, or the start, stop and step attributes. See PEP 260.
466
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000467- A new function fnmatch.filter to filter lists of file names was added.
468
Barry Warsawffd674d2001-05-22 16:00:10 +0000469- calendar.py uses month and day names based on the current locale.
470
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000471- strop is now *really* obsolete (this was announced before with 1.6),
472 and issues DeprecationWarning when used (except for the four items
473 that are still imported into string.py).
474
Tim Petersa814db52001-05-14 07:05:58 +0000475- Cookie.py now sorts key+value pairs by key in output strings.
476
477- pprint.isrecursive(object) didn't correctly identify recursive objects.
478 Now it does.
479
Tim Peters95b3f782001-05-14 18:39:41 +0000480- pprint functions now much faster for large containers (tuple, list, dict).
481
Tim Peters7b9542a2001-06-10 23:40:19 +0000482- New 'q' and 'Q' format codes in the struct module, corresponding to C
483 types "long long" and "unsigned long long" (on Windows, __int64). In
484 native mode, these can be used only when the platform C compiler supports
485 these types (when HAVE_LONG_LONG is #define'd by the Python config
486 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000487 In standard mode, 'q' and 'Q' are supported on all platforms, and are
488 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000489
Guido van Rossum83213cc2001-06-12 16:48:52 +0000490- The site module installs a new built-in function 'help' that invokes
491 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
492 it displays a message reminding the user to use 'help()' or
493 'help(object)'.
494
Tim Petersa814db52001-05-14 07:05:58 +0000495Tests
496
497- New test_mutants.py runs dict comparisons where the key and value
498 comparison operators mutute the dicts randomly during comparison. This
499 rapidly causes Python to crash under earlier releases (not for the faint
500 of heart: it can also cause Win9x to freeze or reboot!).
501
502- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000503 pprint.isreadable() return sensible results. Also verifies that simple
504 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000505
Tim Peters4324aa32001-05-28 22:30:08 +0000506C API
507
508- Removed the unused last_is_sticky argument from the internal
509 _PyTuple_Resize(). If this affects you, you were cheating.
510
511
Guido van Rossum55a78992001-07-17 17:22:32 +0000512======================================================================
513
514
Guido van Rossumffe13be2001-04-16 18:46:45 +0000515What's New in Python 2.1 (final)?
516=================================
517
518We only changed a few things since the last release candidate, all in
519Python library code:
520
521- A bug in the locale module was fixed that affected locales which
522 define no grouping for numeric formatting.
523
524- A few bugs in the weakref module's implementations of weak
525 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
526 and the test suite was updated to check for these bugs.
527
528- An old bug in the os.path.walk() function (introduced in Python
529 2.0!) was fixed: a non-existent file would cause an exception
530 instead of being ignored.
531
532- Fixed a few bugs in the new symtable module found by Neil Norwitz's
533 PyChecker.
534
535
Guido van Rossum5b08f132001-04-16 02:05:23 +0000536What's New in Python 2.1c2?
537===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000538
Guido van Rossum5b08f132001-04-16 02:05:23 +0000539A flurry of small changes, and one showstopper fixed in the nick of
540time made it necessary to release another release candidate. The list
541here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000542
Guido van Rossum5b08f132001-04-16 02:05:23 +0000543Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000544
Guido van Rossum5b08f132001-04-16 02:05:23 +0000545- Tim discovered a nasty bug in the dictionary code, caused by
546 PyDict_Next() calling dict_resize(), and the GC code's use of
547 PyDict_Next() violating an assumption in dict_items(). This was
548 fixed with considerable amounts of band-aid, but the net effect is a
549 saner and more robust implementation.
550
551- Made a bunch of symbols static that were accidentally global.
552
553Build and Ports
554
555- The setup.py script didn't check for a new enough version of zlib
556 (1.1.3 is needed). Now it does.
557
558- Changed "make clean" target to also remove shared libraries.
559
560- Added a more general warning about the SGI Irix optimizer to README.
561
562Library
563
564- Fix a bug in urllib.basejoin("http://host", "../file.html") which
565 omitted the slash between host and file.html.
566
567- The mailbox module's _Mailbox class contained a completely broken
568 and undocumented seek() method. Ripped it out.
569
570- Fixed a bunch of typos in various library modules (urllib2, smtpd,
571 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
572
573- Fixed a few last-minute bugs in unittest.
574
575Extensions
576
577- Reverted the patch to the OpenSSL code in socketmodule.c to support
578 RAND_status() and the EGD, and the subsequent patch that tried to
579 fix it for pre-0.9.5 versions; the problem with the patch is that on
580 some systems it issues a warning whenever socket is imported, and
581 that's unacceptable.
582
583Tests
584
585- Fixed the pickle tests to work with "import test.test_pickle".
586
587- Tweaked test_locale.py to actually run the test Windows.
588
589- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
590 not "wb" (which is not a valid mode at all).
591
592- Fix pstats browser crashes. Import readline if it exists to make
593 the user interface nicer.
594
595- Add "import thread" to the top of test modules that import the
596 threading module (test_asynchat and test_threadedtempfile). This
597 prevents test failures caused by a broken threading module resulting
598 from a previously caught failed import.
599
600- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
601 needed on some platforms (e.g. Solaris 8) when the tests are run
602 twice in succession.
603
604- Skip rather than fail test_sunaudiodev if no audio device is found.
605
606
607What's New in Python 2.1c1?
608===========================
609
610This list was significantly updated when 2.1c2 was released; the 2.1c1
611release didn't mention most changes that were actually part of 2.1c1:
612
613Legal
614
615- Copyright was assigned to the Python Software Foundation (PSF) and a
616 PSF license (very similar to the CNRI license) was added.
617
618- The CNRI copyright notice was updated to include 2001.
619
620Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000621
Guido van Rossumc9932722001-04-12 02:31:27 +0000622- After a public outcry, assignment to __debug__ is no longer illegal;
623 instead, a warning is issued. It will become illegal in 2.2.
624
Guido van Rossum5b08f132001-04-16 02:05:23 +0000625- Fixed a core dump with "%#x" % 0, and changed the semantics so that
626 "%#x" now always prepends "0x", even if the value is zero.
627
628- Fixed some nits in the bytecode compiler.
629
630- Fixed core dumps when calling certain kinds of non-functions.
631
632- Fixed various core dumps caused by reference count bugs.
633
634Build and Ports
635
636- Use INSTALL_SCRIPT to install script files.
637
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000638- New port: SCO Unixware 7, by Billy G. Allie.
639
Guido van Rossum5b08f132001-04-16 02:05:23 +0000640- Updated RISCOS port.
641
642- Updated BeOS port and notes.
643
644- Various other porting problems resolved.
645
646Library
647
648- The TERMIOS and SOCKET modules are now truly obsolete and
649 unnecessary. Their symbols are incorporated in the termios and
650 socket modules.
651
652- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
653 better tests for pickling.
654
655- threading: make Condition.wait() robust against KeyboardInterrupt.
656
657- zipfile: add support to zipfile to support opening an archive
658 represented by an open file rather than a file name. Fix bug where
659 the archive was not properly closed. Fixed a bug in this bugfix
660 where flush() was called for a read-only file.
661
662- imputil: added an uninstall() method to the ImportManager.
663
664- Canvas: fixed bugs in lower() and tkraise() methods.
665
666- SocketServer: API change (added overridable close_request() method)
667 so that the TCP server can explicitly close the request.
668
669- pstats: Eric Raymond added a simple interactive statistics browser,
670 invoked when the module is run as a script.
671
672- locale: fixed a problem in format().
673
674- webbrowser: made it work when the BROWSER environment variable has a
675 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
676 KDE 2. Fixed some other nits.
677
678- unittest: changes to allow using a different exception than
679 AssertionError, and added a few more function aliases. Some other
680 small changes.
681
682- urllib, urllib2: fixed redirect problems and a coupleof other nits.
683
684- asynchat: fixed a critical bug in asynchat that slipped through the
685 2.1b2 release. Fixed another rare bug.
686
687- Fix some unqualified except: clauses (always a bad code example).
688
689XML
690
691- pyexpat: new API get_version_string().
692
693- Fixed some minidom bugs.
694
695Extensions
696
697- Fixed a core dump in _weakref. Removed the weakref.mapping()
698 function (it adds nothing to the API).
699
700- Rationalized the use of header files in the readline module, to make
701 it compile (albeit with some warnings) with the very recent readline
702 4.2, without breaking for earlier versions.
703
704- Hopefully fixed a buffering problem in linuxaudiodev.
705
706- Attempted a fix to make the OpenSSL support in the socket module
707 work again with pre-0.9.5 versions of OpenSSL.
708
709Tests
710
711- Added a test case for asynchat and asyncore.
712
713- Removed coupling between tests where one test failing could break
714 another.
715
716Tools
717
718- Ping added an interactive help browser to pydoc, fixed some nits
719 in the rest of the pydoc code, and added some features to his
720 inspect module.
721
722- An updated python-mode.el version 4.1 which integrates Ken
723 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
724 much nicer in XEmacs and Emacs. When stepping through your program
725 with pdb, in either the shell window or the *Python* window, the
726 source file and line will be tracked by an arrow. Very cool!
727
728- IDLE: syntax warnings in interactive mode are changed into errors.
729
730- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000731 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000732
733- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000734
Barry Warsaw11e89c72001-04-11 20:37:57 +0000735
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000736What's New in Python 2.1 beta 2?
737================================
738
Guido van Rossum053ae352001-03-22 14:17:21 +0000739(Unlisted are many fixed bugs, more documentation, etc.)
740
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000741Core language, builtins, and interpreter
742
Guido van Rossum053ae352001-03-22 14:17:21 +0000743- The nested scopes work (enabled by "from __future__ import
744 nested_scopes") is completed; in particular, the future now extends
745 into code executed through exec, eval() and execfile(), and into the
746 interactive interpreter.
747
748- When calling a base class method (e.g. BaseClass.__init__(self)),
749 this is now allowed even if self is not strictly spoken a class
750 instance (e.g. when using metaclasses or the Don Beaudry hook).
751
752- Slice objects are now comparable but not hashable; this prevents
753 dict[:] from being accepted but meaningless.
754
755- Complex division is now calculated using less braindead algorithms.
756 This doesn't change semantics except it's more likely to give useful
757 results in extreme cases. Complex repr() now uses full precision
758 like float repr().
759
760- sgmllib.py now calls handle_decl() for simple <!...> declarations.
761
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000762- It is illegal to assign to the name __debug__, which is set when the
763 interpreter starts. It is effectively a compile-time constant.
764
765- A warning will be issued if a global statement for a variable
766 follows a use or assignment of that variable.
767
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000768Standard library
769
Guido van Rossum053ae352001-03-22 14:17:21 +0000770- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
771 inspired by JUnit), is now part of the standard library. You now
772 have a choice of two testing frameworks: unittest requires you to
773 write testcases as separate code, doctest gathers them from
774 docstrings. Both approaches have their advantages and
775 disadvantages.
776
777- A new module Tix was added, which wraps the Tix extension library
778 for Tk. With that module, it is not necessary to statically link
779 Tix with _tkinter, since Tix will be loaded with Tcl's "package
780 require" command. See Demo/tix/.
781
782- tzparse.py is now obsolete.
783
784- In gzip.py, the seek() and tell() methods are removed -- they were
785 non-functional anyway, and it's better if callers can test for their
786 existence with hasattr().
787
788Python/C API
789
790- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
791 that's already in the dictionary during a PyDict_Next() iteration.
792 This used to fail occasionally when a dictionary resize operation
793 could be triggered that would rehash all the keys. All other
794 modifications to the dictionary are still off-limits during a
795 PyDict_Next() iteration!
796
797- New extended APIs related to passing compiler variables around.
798
799- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
800 implement isinstance() and issubclass().
801
802- Py_BuildValue() now has a "D" conversion to create a Python complex
803 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000804
Fred Drake4e262a92001-03-22 18:26:47 +0000805- Extensions types which support weak references must now set the
806 field allocated for the weak reference machinery to NULL themselves;
807 this is done to avoid the cost of checking each object for having a
808 weakly referencable type in PyObject_INIT(), since most types are
809 not weakly referencable.
810
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000811- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
812 free variables and cell variables to and from the frame's f_locals.
813
814- Variants of several functions defined in pythonrun.h have been added
815 to support the nested_scopes future statement. The variants all end
816 in Flags and take an extra argument, a PyCompilerFlags *; examples:
817 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
818 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000819 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000820
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000821Distutils
822
823- the sdist command now writes a PKG-INFO file, as described in PEP 241,
824 into the release tree.
825
Tim Peters0e57abf2001-05-02 07:39:38 +0000826- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000827 (an uninstaller, more customization of the installer's display)
828
829- from Jack Jansen: added Mac-specific code to generate a dialog for
830 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000831 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000832 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000833
834- added 'platforms' and 'keywords' to the set of metadata that can be
835 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000836
837- applied patches from Jason Tishler to make the compiler class work with
838 Cygwin.
839
840
Tim Peters2fe289a2001-03-01 22:19:38 +0000841What's New in Python 2.1 beta 1?
842================================
Tim Petersd66595f2001-02-04 03:09:53 +0000843
844Core language, builtins, and interpreter
845
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000846- Following an outcry from the community about the amount of code
847 broken by the nested scopes feature introduced in 2.1a2, we decided
848 to make this feature optional, and to wait until Python 2.2 (or at
849 least 6 months) to make it standard. The option can be enabled on a
850 per-module basis by adding "from __future__ import nested_scopes" at
851 the beginning of a module (before any other statements, but after
852 comments and an optional docstring). See PEP 236 (Back to the
853 __future__) for a description of the __future__ statement. PEP 227
854 (Statically Nested Scopes) has been updated to reflect this change,
855 and to clarify the semantics in a number of endcases.
856
857- The nested scopes code, when enabled, has been hardened, and most
858 bugs and memory leaks in it have been fixed.
859
860- Compile-time warnings are now generated for a number of conditions
861 that will break or change in meaning when nested scopes are enabled:
862
863 - Using "from...import *" or "exec" without in-clause in a function
864 scope that also defines a lambda or nested function with one or
865 more free (non-local) variables. The presence of the import* or
866 bare exec makes it impossible for the compiler to determine the
867 exact set of local variables in the outer scope, which makes it
868 impossible to determine the bindings for free variables in the
869 inner scope. To avoid the warning about import *, change it into
870 an import of explicitly name object, or move the import* statement
871 to the global scope; to avoid the warning about bare exec, use
872 exec...in... (a good idea anyway -- there's a possibility that
873 bare exec will be deprecated in the future).
874
875 - Use of a global variable in a nested scope with the same name as a
876 local variable in a surrounding scope. This will change in
877 meaning with nested scopes: the name in the inner scope will
878 reference the variable in the outer scope rather than the global
879 of the same name. To avoid the warning, either rename the outer
880 variable, or use a global statement in the inner function.
881
Neil Schemenauera35c6882001-02-27 04:45:05 +0000882- An optional object allocator has been included. This allocator is
883 optimized for Python objects and should be faster and use less memory
884 than the standard system allocator. It is not enabled by default
885 because of possible thread safety problems. The allocator is only
886 protected by the Python interpreter lock and it is possible that some
887 extension modules require a thread safe allocator. The object
888 allocator can be enabled by providing the "--with-pymalloc" option to
889 configure.
890
Tim Petersd66595f2001-02-04 03:09:53 +0000891Standard library
892
Martin v. Löwis2a5130e2001-02-27 04:21:58 +0000893- pyexpat now detects the expat version if expat.h defines it. A
894 number of additional handlers are provided, which are only available
895 since expat 1.95. In addition, the methods SetParamEntityParsing and
896 GetInputContext of Parser objects are available with 1.95.x
897 only. Parser objects now provide the ordered_attributes and
898 specified_attributes attributes. A new module expat.model was added,
899 which offers a number of additional constants if 1.95.x is used.
900
901- xml.dom offers the new functions registerDOMImplementation and
902 getDOMImplementation.
903
904- xml.dom.minidom offers a toprettyxml method. A number of DOM
905 conformance issues have been resolved. In particular, Element now
906 has an hasAttributes method, and the handling of namespaces was
907 improved.
908
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000909- Ka-Ping Yee contributed two new modules: inspect.py, a module for
910 getting information about live Python code, and pydoc.py, a module
911 for interactively converting docstrings to HTML or text.
912 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +0000913 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +0000914 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
915 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +0000916
Tim Peters1eff7962001-03-01 02:31:33 +0000917- New library module difflib.py, primarily packaging the SequenceMatcher
918 class at the heart of the popular ndiff.py file-comparison tool.
919
920- doctest.py (a framework for verifying Python code examples in docstrings)
921 is now part of the std library.
922
Tim Petersd66595f2001-02-04 03:09:53 +0000923Windows changes
924
Guido van Rossume3955a82001-03-02 14:05:59 +0000925- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
926 small GUI that lets you browse the module docstrings using your
927 default web browser.
928
Tim Peters1eff7962001-03-01 02:31:33 +0000929- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
930 Platforms) is implemented. See
931
932 http://python.sourceforge.net/peps/pep-0235.html
933
934 for full details, especially the "Current Lower-Left Semantics" section.
935 The new Windows import rules are simpler than before:
936
937 A. If the PYTHONCASEOK environment variable exists, same as
938 before: silently accept the first case-insensitive match of any
939 kind; raise ImportError if none found.
940
941 B. Else search sys.path for the first case-sensitive match; raise
942 ImportError if none found.
943
944 The same rules have been implented on other platforms with case-
945 insensitive but case-preserving filesystems too (including Cygwin, and
946 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +0000947
Tim Peters25a9ce32001-02-19 07:06:36 +0000948- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
949 what it's supposed to do (and does do under NT and 2000) via direct
950 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +0000951 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +0000952 all Win9x systems before.
953
Tim Peters1eff7962001-03-01 02:31:33 +0000954- Build: Subproject _test (effectively) renamed to _testcapi.
955
Tim Peters2fe289a2001-03-01 22:19:38 +0000956New platforms
957
958- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
959 Thanks to Steven Majewski!
960
961- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
962 Tishler!
963
Guido van Rossum9089b272001-03-02 06:49:50 +0000964- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
965 Schwertberger! See RISCOS/README for more information -- it seems
966 that because of the bizarre filename conventions on RISCOS, no port
967 to that platform is easy. Note that the new variable os.endsep is
968 silently supported in order to make life easier on this platform,
969 but we don't advertise it because it's not worth for most folks to
970 care about RISCOS portability.
971
Tim Peters25a9ce32001-02-19 07:06:36 +0000972
Tim Petersd7b5e882001-01-25 03:36:26 +0000973What's New in Python 2.1 alpha 2?
974=================================
Tim Peters40ead762001-01-27 05:35:26 +0000975
Tim Petersd7b5e882001-01-25 03:36:26 +0000976Core language, builtins, and interpreter
977
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000978- Scopes nest. If a name is used in a function or class, but is not
979 local, the definition in the nearest enclosing function scope will
980 be used. One consequence of this change is that lambda statements
981 could reference variables in the namespaces where the lambda is
982 defined. In some unusual cases, this change will break code.
983
984 In all previous version of Python, names were resolved in exactly
985 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +0000986 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +0000987 function A is defined within a function B, the names bound in B are
988 not visible in A. The new rules make names bound in B visible in A,
989 unless A contains a name binding that hides the binding in B.
990
991 Section 4.1 of the reference manual describes the new scoping rules
992 in detail. The test script in Lib/test/test_scope.py demonstrates
993 some of the effects of the change.
994
995 The new rules will cause existing code to break if it defines nested
996 functions where an outer function has local variables with the same
997 name as globals or builtins used by the inner function. Example:
998
999 def munge(str):
1000 def helper(x):
1001 return str(x)
1002 if type(str) != type(''):
1003 str = helper(str)
1004 return str.strip()
1005
1006 Under the old rules, the name str in helper() is bound to the
1007 builtin function str(). Under the new rules, it will be bound to
1008 the argument named str and an error will occur when helper() is
1009 called.
1010
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001011- The compiler will report a SyntaxError if "from ... import *" occurs
1012 in a function or class scope. The language reference has documented
1013 that this case is illegal, but the compiler never checked for it.
1014 The recent introduction of nested scope makes the meaning of this
1015 form of name binding ambiguous. In a future release, the compiler
1016 may allow this form when there is no possibility of ambiguity.
1017
Tim Peters40ead762001-01-27 05:35:26 +00001018- repr(string) is easier to read, now using hex escapes instead of octal,
1019 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1020
1021 >>> "\texample \r\n" + chr(0) + chr(255)
1022 '\texample \r\n\x00\xff' # in 2.1
1023 '\011example \015\012\000\377' # in 2.0
1024
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001025- Functions are now compared and hashed by identity, not by value, since
1026 the func_code attribute is writable.
1027
Fred Drakefb9d7122001-02-01 20:00:40 +00001028- Weak references (PEP 205) have been added. This involves a few
1029 changes in the core, an extension module (_weakref), and a Python
1030 module (weakref). The weakref module is the public interface. It
1031 includes support for "explicit" weak references, proxy objects, and
1032 mappings with weakly held values.
1033
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001034- A 'continue' statement can now appear in a try block within the body
1035 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001036 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001037
Tim Petersd7b5e882001-01-25 03:36:26 +00001038Standard library
1039
Barry Warsaw30dbd142001-01-31 22:14:01 +00001040- mailbox.py now has a new class, PortableUnixMailbox which is
1041 identical to UnixMailbox but uses a more portable scheme for
1042 determining From_ separators. Also, the constructors for all the
1043 classes in this module have a new optional `factory' argument, which
1044 is a callable used when new message classes must be instantiated by
1045 the next() method.
1046
Tim Petersd7b5e882001-01-25 03:36:26 +00001047- random.py is now self-contained, and offers all the functionality of
1048 the now-deprecated whrandom.py. See the docs for details. random.py
1049 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001050 and restoring the internal state of the generator; and jumpahead(n),
1051 for quickly forcing the internal state to be the same as if n calls to
1052 random() had been made. The latter is particularly useful for multi-
1053 threaded programs, creating one instance of the random.Random() class for
1054 each thread, then using .jumpahead() to force each instance to use a
1055 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001056
Tim Peters0de88fc2001-02-01 04:59:18 +00001057- random.py's seed() function is new. For bit-for-bit compatibility with
1058 prior releases, use the whseed function instead. The new seed function
1059 addresses two problems: (1) The old function couldn't produce more than
1060 about 2**24 distinct internal states; the new one about 2**45 (the best
1061 that can be done in the Wichmann-Hill generator). (2) The old function
1062 sometimes produced identical internal states when passed distinct
1063 integers, and there was no simple way to predict when that would happen;
1064 the new one guarantees to produce distinct internal states for all
1065 arguments in [0, 27814431486576L).
1066
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001067- The socket module now supports raw packets on Linux. The socket
1068 family is AF_PACKET.
1069
Tim Peters9ea17ac2001-02-02 05:57:15 +00001070- test_capi.py is a start at running tests of the Python C API. The tests
1071 are implemented by the new Modules/_testmodule.c.
1072
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001073- A new extension module, _symtable, provides provisional access to the
1074 internal symbol table used by the Python compiler. A higher-level
1075 interface will be added on top of _symtable in a future release.
1076
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001077- Removed the obsolete soundex module.
1078
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001079- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1080 the isSameNode method; NamedNodeMap the get method.
1081
1082- xml.sax.expatreader supports the lexical handler property; it
1083 generates comment, startCDATA, and endCDATA events.
1084
Tim Petersee826f82001-01-31 19:39:44 +00001085Windows changes
1086
1087- Build procedure: the zlib project is built in a different way that
1088 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001089 the zlib binary used. See PCbuild\readme.txt for details. Your old
1090 zlib-related directories can be deleted; you'll need to download fresh
1091 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001092
Tim Peters9ea17ac2001-02-02 05:57:15 +00001093- Build: New subproject _test for the benefit of test_capi.py (see above).
1094
Tim Petersb16c56f2001-02-02 21:24:51 +00001095- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1096 interface to some Python compiler internals).
1097
1098- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001099 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001100
Tim Petersa3a3a032000-11-30 05:22:44 +00001101What's New in Python 2.1 alpha 1?
1102=================================
1103
1104Core language, builtins, and interpreter
1105
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001106- There is a new Unicode companion to the PyObject_Str() API
1107 called PyObject_Unicode(). It behaves in the same way as the
1108 former, but assures that the returned value is an Unicode object
1109 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001110
Guido van Rossumf98eda02001-01-17 15:54:45 +00001111- The comparison operators support "rich comparison overloading" (PEP
1112 207). C extension types can provide a rich comparison function in
1113 the new tp_richcompare slot in the type object. The cmp() function
1114 and the C function PyObject_Compare() first try the new rich
1115 comparison operators before trying the old 3-way comparison. There
1116 is also a new C API PyObject_RichCompare() (which also falls back on
1117 the old 3-way comparison, but does not constrain the outcome of the
1118 rich comparison to a Boolean result).
1119
1120 The rich comparison function takes two objects (at least one of
1121 which is guaranteed to have the type that provided the function) and
1122 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1123 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1124 object, which may be NotImplemented (in which case the tp_compare
1125 slot function is used as a fallback, if defined).
1126
1127 Classes can overload individual comparison operators by defining one
1128 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001129 __ge__. There are no explicit "reflected argument" versions of
1130 these; instead, __lt__ and __gt__ are each other's reflection,
1131 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1132 reflection (similar at the C level). No other implications are
1133 made; in particular, Python does not assume that == is the Boolean
1134 inverse of !=, or that < is the Boolean inverse of >=. This makes
1135 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001136
1137 Classes or types that want to implement (in)equality tests but not
1138 the ordering operators (i.e. unordered types) should implement ==
1139 and !=, and raise an error for the ordering operators.
1140
Guido van Rossuma88479f2001-01-18 14:28:08 +00001141 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001142 Boolean; e.g. a matrix type might want to return a matrix of bits
1143 for A < B, giving elementwise comparisons. Such types should ensure
1144 that any interpretation of their value in a Boolean context raises
1145 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1146 at the C level) to always raise an exception.
1147
Guido van Rossuma88479f2001-01-18 14:28:08 +00001148- Complex numbers use rich comparisons to define == and != but raise
1149 an exception for <, <=, > and >=. Unfortunately, this also means
1150 that cmp() of two complex numbers raises an exception when the two
1151 numbers differ. Since it is not mathematically meaningful to compare
1152 complex numbers except for equality, I hope that this doesn't break
1153 too much code.
1154
Tim Peters3389f192001-02-18 08:48:49 +00001155- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001156 not defined by the language, other than that it's arbitrary but
1157 consistent (see the Reference Manual). An implementation detail changed
1158 in 2.1a1 such that None now compares less than any other object. Code
1159 relying on this new behavior (like code that relied on the previous
1160 behavior) does so at its own risk.
1161
Barry Warsaw573b5412001-01-15 20:43:18 +00001162- Functions and methods now support getting and setting arbitrarily
1163 named attributes (PEP 232). Functions have a new __dict__
1164 (a.k.a. func_dict) which hold the function attributes. Methods get
1165 and set attributes on their underlying im_func. It is a TypeError
1166 to set an attribute on a bound method.
1167
Guido van Rossum051e3352001-01-15 19:11:10 +00001168- The xrange() object implementation has been improved so that
1169 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1170 limitation that in this case len(xrange(sys.maxint)) can't be
1171 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1172 work fine as long as the index i doesn't actually reach 2**31.
1173 (Python uses regular ints for sequence and string indices; fixing
1174 that is much more work.)
1175
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001176- Two changes to from...import:
1177
Guido van Rossumba381232001-02-03 15:06:40 +00001178 1) "from M import X" now works even if (after loading module M)
1179 sys.modules['M'] is not a real module; it's basically a getattr()
1180 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001181
1182 2) "from M import *" now looks for M.__all__ to decide which names to
1183 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1184 filters out names starting with '_' as before. Whether or not
1185 __all__ exists, there's no restriction on the type of M.
1186
Guido van Rossumf61f1662001-01-10 20:13:55 +00001187- File objects have a new method, xreadlines(). This is the fastest
1188 way to iterate over all lines in a file:
1189
1190 for line in file.xreadlines():
1191 ...do something to line...
1192
1193 See the xreadlines module (mentioned below) for how to do this for
1194 other file-like objects.
1195
1196- Even if you don't use file.xreadlines(), you may expect a speedup on
1197 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001198 quite a bit in platform-specific ways: on systems (like Linux) that
1199 support flockfile(), getc_unlocked(), and funlockfile(), those are
1200 used by default. On systems (like Windows) without getc_unlocked(),
1201 a complicated (but still thread-safe) method using fgets() is used by
1202 default.
1203
Tim Petersd52269b2001-01-25 06:23:18 +00001204 You can force use of the fgets() method by #define'ing
1205 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001206 getc_unlocked()).
1207
Tim Petersd52269b2001-01-25 06:23:18 +00001208 You can force fgets() not to be used by #define'ing
1209 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001210 test_bufio.py fails -- and let us know if it does!).
1211
1212- In addition, the fileinput module, while still slower than the other
1213 methods on most platforms, has been sped up too, by using
1214 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001215
1216- Support for run-time warnings has been added, including a new
1217 command line option (-W) to specify the disposition of warnings.
1218 See the description of the warnings module below.
1219
1220- Extensive changes have been made to the coercion code. This mostly
1221 affects extension modules (which can now implement mixed-type
1222 numerical operators without having to use coercion), but
1223 occasionally, in boundary cases the coercion semantics have changed
1224 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001225 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001226 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001227 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001228
Guido van Rossumf98eda02001-01-17 15:54:45 +00001229- In connection with the coercion changes, a new built-in singleton
1230 object, NotImplemented is defined. This can be returned for
1231 operations that wish to indicate they are not implemented for a
1232 particular combination of arguments. From C, this is
1233 Py_NotImplemented.
1234
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001235- The interpreter accepts now bytecode files on the command line even
1236 if they do not have a .pyc or .pyo extension. On Linux, after executing
1237
Martin v. Löwise214baa2001-02-04 22:37:56 +00001238import imp,sys,string
1239magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1240reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1241open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001242
1243 any byte code file can be used as an executable (i.e. as an argument
1244 to execve(2)).
1245
Tim Peters9940b802000-12-01 07:59:35 +00001246- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001247 character. In 1.6 and earlier, they never produced a sign,
1248 and raised an error if the value of the long was too large
1249 to fit in a Python int. In 2.0, they produced a sign if and
1250 only if too large to fit in an int. This was inconsistent
1251 across platforms (because the size of an int varies across
1252 platforms), and inconsistent with hex() and oct(). Example:
1253
1254 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001255 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001256 'ffffffbe' # in 2.0 and before, on 32-bit machines
1257 >>> hex(-0x42L)
1258 '-0x42L' # in all versions of Python
1259
Tim Peters9940b802000-12-01 07:59:35 +00001260 The behavior of %d formats for negative Python longs remains
1261 the same as in 2.0 (although in 1.6 and before, they raised
1262 an error if the long didn't fit in a Python int).
1263
1264 %u formats don't make sense for Python longs, but are allowed
1265 and treated the same as %d in 2.1. In 2.0, a negative long
1266 formatted via %u produced a sign if and only if too large to
1267 fit in an int. In 1.6 and earlier, a negative long formatted
1268 via %u raised an error if it was too big to fit in an int.
1269
Guido van Rossum3661d392000-12-12 22:10:31 +00001270- Dictionary objects have an odd new method, popitem(). This removes
1271 an arbitrary item from the dictionary and returns it (in the form of
1272 a (key, value) pair). This can be useful for algorithms that use a
1273 dictionary as a bag of "to do" items and repeatedly need to pick one
1274 item. Such algorithms normally end up running in quadratic time;
1275 using popitem() they can usually be made to run in linear time.
1276
Tim Peters36cdad12000-12-29 02:06:45 +00001277Standard library
1278
Thomas Woutersfe385252001-01-19 23:16:56 +00001279- In the time module, the time argument to the functions strftime,
1280 localtime, gmtime, asctime and ctime is now optional, defaulting to
1281 the current time (in the local timezone).
1282
Guido van Rossumda91f222001-01-15 16:36:08 +00001283- The ftplib module now defaults to passive mode, which is deemed a
1284 more useful default given that clients are often inside firewalls
1285 these days. Note that this could break if ftplib is used to connect
1286 to a *server* that is inside a firewall, from outside; this is
1287 expected to be a very rare situation. To fix that, you can call
1288 ftp.set_pasv(0).
1289
Martin v. Löwis10a27872001-01-13 09:54:41 +00001290- The module site now treats .pth files not only for path configuration,
1291 but also supports extensions to the initialization code: Lines starting
1292 with import are executed.
1293
Guido van Rossumf61f1662001-01-10 20:13:55 +00001294- There's a new module, warnings, which implements a mechanism for
1295 issuing and filtering warnings. There are some new built-in
1296 exceptions that serve as warning categories, and a new command line
1297 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1298 turns warnings into errors). warnings.warn(message[, category])
1299 issues a warning message; this can also be called from C as
1300 PyErr_Warn(category, message).
1301
1302- A new module xreadlines was added. This exports a single factory
1303 function, xreadlines(). The intention is that this code is the
1304 absolutely fastest way to iterate over all lines in an open
1305 file(-like) object:
1306
1307 import xreadlines
1308 for line in xreadlines.xreadlines(file):
1309 ...do something to line...
1310
1311 This is equivalent to the previous the speed record holder using
1312 file.readlines(sizehint). Note that if file is a real file object
1313 (as opposed to a file-like object), this is equivalent:
1314
1315 for line in file.xreadlines():
1316 ...do something to line...
1317
Tim Peters36cdad12000-12-29 02:06:45 +00001318- The bisect module has new functions bisect_left, insort_left,
1319 bisect_right and insort_right. The old names bisect and insort
1320 are now aliases for bisect_right and insort_right. XXX_right
1321 and XXX_left methods differ in what happens when the new element
1322 compares equal to one or more elements already in the list: the
1323 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001324 right. Code that doesn't care where equal elements end up should
1325 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001326
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001327- The new curses.panel module wraps the panel library that forms part
1328 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1329
Guido van Rossumf61f1662001-01-10 20:13:55 +00001330- The SocketServer module now sets the allow_reuse_address flag by
1331 default in the TCPServer class.
1332
1333- A new function, sys._getframe(), returns the stack frame pointer of
1334 the caller. This is intended only as a building block for
1335 higher-level mechanisms such as string interpolation.
1336
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001337- The pyexpat module supports a number of new handlers, which are
1338 available only in expat 1.2. If invocation of a callback fails, it
1339 will report an additional frame in the traceback. Parser objects
1340 participate now in garbage collection. If expat reports an unknown
1341 encoding, pyexpat will try to use a Python codec; that works only
1342 for single-byte charsets. The parser type objects is exposed as
1343 XMLParserObject.
1344
1345- xml.dom now offers standard definitions for symbolic node type and
1346 exception code constants, and a hierarchy of DOM exceptions. minidom
1347 was adjusted to use them.
1348
1349- The conformance of xml.dom.minidom to the DOM specification was
1350 improved. It detects a number of additional error cases; the
1351 previous/next relationship works even when the tree is modified;
1352 Node supports the normalize() method; NamedNodeMap, DocumentType and
1353 DOMImplementation classes were added; Element supports the
1354 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1355 method.
1356
Guido van Rossumf61f1662001-01-10 20:13:55 +00001357Build issues
1358
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001359- For Unix (and Unix-compatible) builds, configuration and building of
1360 extension modules is now greatly automated. Rather than having to
1361 edit the Modules/Setup file to indicate which modules should be
1362 built and where their include files and libraries are, a
1363 distutils-based setup.py script now takes care of building most
1364 extension modules. All extension modules built this way are built
1365 as shared libraries. Only a few modules that must be linked
1366 statically are still listed in the Setup file; you won't need to
1367 edit their configuration.
1368
1369- Python should now build out of the box on Cygwin. If it doesn't,
1370 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001371
1372- Python now always uses its own (renamed) implementation of getopt()
1373 -- there's too much variation among C library getopt()
1374 implementations.
1375
1376- C++ compilers are better supported; the CXX macro is always set to a
1377 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001378
Tim Petersd92dfe02000-12-12 01:18:41 +00001379Windows changes
1380
1381- select module: By default under Windows, a select() call
1382 can specify no more than 64 sockets. Python now boosts
1383 this Microsoft default to 512. If you need even more than
1384 that, see the MS docs (you'll need to #define FD_SETSIZE
1385 and recompile Python from source).
1386
Guido van Rossumf61f1662001-01-10 20:13:55 +00001387- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1388 subdirectory is no more!
1389
Tim Petersa3a3a032000-11-30 05:22:44 +00001390
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001391What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001392=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001393
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001394Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001395changes are in the file HISTORY. If you are making the jump directly
1396from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1397HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001398
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001399Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1400the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1401http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001402
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001403--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001404
1405======================================================================
1406
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001407What's new in 2.0 (since release candidate 1)?
1408==============================================
1409
1410Standard library
1411
1412- The copy_reg module was modified to clarify its intended use: to
1413 register pickle support for extension types, not for classes.
1414 pickle() will raise a TypeError if it is passed a class.
1415
1416- Fixed a bug in gettext's "normalize and expand" code that prevented
1417 it from finding an existing .mo file.
1418
1419- Restored support for HTTP/0.9 servers in httplib.
1420
Tim Peters989b7b92000-10-16 20:24:53 +00001421- The math module was changed to stop raising OverflowError in case of
1422 underflow, and return 0 instead in underflow cases. Whether Python
1423 used to raise OverflowError in case of underflow was platform-
1424 dependent (it did when the platform math library set errno to ERANGE
1425 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001426
1427- Fixed a bug in StringIO that occurred when the file position was not
1428 at the end of the file and write() was called with enough data to
1429 extend past the end of the file.
1430
1431- Fixed a bug that caused Tkinter error messages to get lost on
1432 Windows. The bug was fixed by replacing direct use of
1433 interp->result with Tcl_GetStringResult(interp).
1434
1435- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1436 redirect response.
1437
1438- Several changes were made to distutils: Some debugging code was
1439 removed from util. Fixed the installer used when an external zip
1440 program (like WinZip) is not found; the source code for this
1441 installer is in Misc/distutils. check_lib() was modified to behave
1442 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1443 test for whether installed modules are on sys.path was changed to
1444 use both normcase() and normpath().
1445
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001446- Several minor bugs were fixed in the xml package (the minidom,
1447 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001448
1449- The regression test driver (regrtest.py) behavior when invoked with
1450 -l changed: It now reports a count of objects that are recognized as
1451 garbage but not freed by the garbage collector.
1452
Tim Peters989b7b92000-10-16 20:24:53 +00001453- The regression test for the math module was changed to test
1454 exceptional behavior when the test is run in verbose mode. Python
1455 cannot yet guarantee consistent exception behavior across platforms,
1456 so the exception part of test_math is run only in verbose mode, and
1457 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001458
1459Internals
1460
1461- PyOS_CheckStack() has been disabled on Win64, where it caused
1462 test_sre to fail.
1463
1464Build issues
1465
1466- Changed compiler flags, so that gcc is always invoked with -Wall and
1467 -Wstrict-prototypes. Users compiling Python with GCC should see
1468 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001469 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001470 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001471
Tim Petersa3a3a032000-11-30 05:22:44 +00001472- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001473
1474Tools and other miscellany
1475
1476- The compiler in Tools/compiler was updated to support the new
1477 language features introduced in 2.0: extended print statement, list
1478 comprehensions, and augmented assignments. The new compiler should
1479 also be backwards compatible with Python 1.5.2; the compiler will
1480 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001481 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001482
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001483What's new in 2.0 release candidate 1 (since beta 2)?
1484=====================================================
1485
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001486What is release candidate 1?
1487
1488We believe that release candidate 1 will fix all known bugs that we
1489intend to fix for the 2.0 final release. This release should be a bit
1490more stable than the previous betas. We would like to see even more
1491widespread testing before the final release, so we are producing this
1492release candidate. The final release will be exactly the same unless
1493any show-stopping (or brown bag) bugs are found by testers of the
1494release candidate.
1495
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001496All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001497to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001498
1499Core language, builtins, and interpreter
1500
1501- A bug that caused crashes when __coerce__ was used with augmented
1502 assignment, e.g. +=, was fixed.
1503
1504- Raise ZeroDivisionError when raising zero to a negative number,
1505 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1506 power operator and the result of math.pow(0.0, -2.0) will vary by
1507 platform. On Linux, it raises a ValueError.
1508
1509- A bug in Unicode string interpolation was fixed that occasionally
1510 caused errors with formats including "%%". For example, the
1511 following expression "%% %s" % u"abc" no longer raises a TypeError.
1512
1513- Compilation of deeply nested expressions raises MemoryError instead
1514 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1515
1516- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1517 rendering them useless. They are now written in binary mode again.
1518
1519Standard library
1520
1521- Keyword arguments are now accepted for most pattern and match object
1522 methods in SRE, the standard regular expression engine.
1523
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001524- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001525 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001526
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001527- Several bugs in the Unicode handling and error handling in _tkinter
1528 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001529
1530- Fix memory management errors in Merge() and Tkapp_Call() routines.
1531
1532- Several changes were made to cStringIO to make it compatible with
1533 the file-like object interface and with StringIO. If operations are
1534 performed on a closed object, an exception is raised. The truncate
1535 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001536 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001537
1538- There were many changes made to the linuxaudiodev module and its
1539 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001540 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001541
1542 Note that this module is named poorly, because it should work
1543 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001544 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001545
1546 The module now raises exceptions when errors occur instead of
1547 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1548 audio) and defines a getptr() method that calls the
1549 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1550
1551- The library_version attribute, introduced in an earlier beta, was
1552 removed because it can not be supported with early versions of the C
1553 readline library, which provides no way to determine the version at
1554 compile-time.
1555
1556- The binascii module is now enabled on Win64.
1557
Tim Peters46446d62000-10-09 21:19:31 +00001558- tokenize.py no longer suffers "recursion depth" errors when parsing
1559 programs with very long string literals.
1560
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001561Internals
1562
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001563- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001564 which is called when the interpreter starts up to determine where
1565 the standard library is installed. These vulnerabilities affect all
1566 previous versions of Python and can be exploited by setting very
1567 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1568 setuid Python script, although use of the wrapper in
1569 Misc/setuid-prog.c will eliminate the vulnerability.
1570
1571- Fixed garbage collection bugs in instance creation that were
1572 triggered when errors occurred during initialization. The solution,
1573 applied in cPickle and in PyInstance_New(), is to call
1574 PyObject_GC_Init() after the initialization of the object's
1575 container attributes is complete.
1576
1577- pyexpat adds definitions of PyModule_AddStringConstant and
1578 PyModule_AddObject if the Python version is less than 2.0, which
1579 provides compatibility with PyXML on Python 1.5.2.
1580
1581- If the platform has a bogus definition for LONG_BIT (the number of
1582 bits in a long), an error will be reported at compile time.
1583
1584- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1585 collection crashes and possibly other, unreported crashes.
1586
1587- Fixed a memory leak in _PyUnicode_Fini().
1588
1589Build issues
1590
1591- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001592 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001593 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001594
1595- The mmap.PAGESIZE constant is now initialized using sysconf when
1596 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1597
1598- The md5 file should now compile on all platforms.
1599
1600- The select module now compiles on platforms that do not define
1601 POLLRDNORM and related constants.
1602
1603- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001604 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001605
Jeremy Hylton10921202000-10-09 18:34:12 +00001606- BeOS: A number of changes were made to the build and installation
1607 process. ar-fake now operates on a directory of object files.
1608 dl_export.h is gone, and its macros now appear on the mwcc command
1609 line during build on PPC BeOS.
1610
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001611- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001612 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001613
1614- Cygwin: Support for shared libraries, Tkinter, and sockets.
1615
1616- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1617
1618Tools and other miscellany
1619
1620- Removed debugging prints from main used with freeze.
1621
Tim Peters46446d62000-10-09 21:19:31 +00001622- IDLE auto-indent no longer crashes when it encounters Unicode
1623 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001624
1625What's new in 2.0 beta 2 (since beta 1)?
1626========================================
1627
1628Core language, builtins, and interpreter
1629
Tim Peters482c0212000-09-26 06:33:09 +00001630- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001631 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001632
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001633- Add -h and -V command line options to print the usage message and
1634 Python version number and exit immediately.
1635
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001636- eval() and exec accept Unicode objects as code parameters.
1637
1638- getattr() and setattr() now also accept Unicode objects for the
1639 attribute name, which are converted to strings using the default
1640 encoding before lookup.
1641
1642- Multiplication on string and Unicode now does proper bounds
1643 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1644 string is too long."
1645
1646- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001647 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001648
Jeremy Hylton1b618592000-09-26 05:32:36 +00001649
1650Standard library and extensions
1651
Guido van Rossum5b08f132001-04-16 02:05:23 +00001652- socket module: the OpenSSL code now adds support for RAND_status()
1653 and EGD (Entropy Gathering Device).
1654
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001655- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001656 argument checking; it still takes no arguments.
1657
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001658- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001659
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001660- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001661
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001662- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001663
1664- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001665 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001666
1667- copy: Copy Unicode objects atomically.
1668
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001669- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001670
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001671- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001672
Fred Drake67233bc2000-09-26 16:40:27 +00001673- dbm: Add get() and setdefault() methods to dbm object. Add constant
1674 `library' to module that names the library used. Added doc strings
1675 and method names to error messages. Uses configure to determine
1676 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1677 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001678
1679- distutils: Update to version 0.9.3.
1680
1681- dl: Add several dl.RTLD_ constants.
1682
1683- fpectl: Now supported on FreeBSD.
1684
1685- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1686 found by the collector will be saved in gc.garbage. This is useful
1687 for debugging a program that creates reference cycles.
1688
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001689- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001690 of HTTP class. Do not close socket on zero-length response. Do not
1691 crash when server sends invalid content-length header.
1692
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001693- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001694
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001695- marshal: When reading a short, sign-extend on platforms where shorts
1696 are bigger than 16 bits. When reading a long, repair the unportable
1697 sign extension that was being done for 64-bit machines. (It assumed
1698 that signed right shift sign-extends.)
1699
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001700- operator: Add contains(), invert(), __invert__() as aliases for
1701 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001702
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001703- os: Add support for popen2() and popen3() on all platforms where
1704 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001705
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001706- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001707 clicking on a file in Explorer (or passing the file name to the
1708 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001709
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001710- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001711 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001712
1713- pickle: Now raises ValueError when an invalid pickle that contains
1714 a non-string repr where a string repr was expected. This behavior
1715 matches cPickle.
1716
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001717- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001718
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001719- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001720
1721- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001722 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001723 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001724
1725- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001726 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001727
1728- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001729 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001730 few cycles during startup since the first call to
1731 setdefaultencoding() will initialize the codec registry and the
1732 encodings package.
1733
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001734- socket: Support for size hint in readlines() method of object returned
1735 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001736
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001737- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001738 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001739 is followed by whitespace.
1740
Tim Petersa3a3a032000-11-30 05:22:44 +00001741- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001742
1743- struct: Check ranges for bytes and shorts.
1744
1745- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001746 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001747
1748- Tkinter: Image objects are now guaranteed to have unique ids. Set
1749 event.delta to zero if Tk version doesn't support mousewheel.
1750 Removed some debugging prints.
1751
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001752- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001753
Fred Drake67233bc2000-09-26 16:40:27 +00001754- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001755 which works around a bug in Norton AntiVirus 2000 that leads directly
1756 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001757
1758- xml: New version detection code allows PyXML to override standard
1759 XML package if PyXML version is greater than 0.6.1.
1760
Fred Drake64bb3802000-09-26 16:21:35 +00001761- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1762 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1763 tree only for nodes which are sufficiently interesting to a specific
1764 application. Does not provide the HTML-specific extensions. Still
1765 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001766
Fred Drake64bb3802000-09-26 16:21:35 +00001767- xml.sax: SAX 2 support for Python, including all the handler
1768 interfaces needed to process XML 1.0 compliant XML. Some
1769 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001770
Fred Drake64bb3802000-09-26 16:21:35 +00001771- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1772 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001773
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001774
Jeremy Hylton1b618592000-09-26 05:32:36 +00001775C API
1776
1777- Add three new convenience functions for module initialization --
1778 PyModule_AddObject(), PyModule_AddIntConstant(), and
1779 PyModule_AddStringConstant().
1780
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001781- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001782 removed and add #error to Python.h if NULL isn't defined after
1783 #include of stdio.h.
1784
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001785- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001786 backwards compatibility (at the source level) with old extensions.
1787
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001788- A wrapper API was added for signal() and sigaction(). Instead of
1789 either function, always use PyOS_getsig() to get a signal handler
1790 and PyOS_setsig() to set one. A new convenience typedef
1791 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001792
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001793- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001794 internal data buffer and size of a string object -- or the default
1795 encoded version of a Unicode object.
1796
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001797- PyString_Size() and PyString_AsString() accept Unicode objects.
1798
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001799- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001800 exists). INT_MAX and LONG_MAX will always be defined, even if
1801 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001802
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001803- PyFloat_FromString takes a second argument, pend, that was
1804 effectively useless. It is now officially useless but preserved for
1805 backwards compatibility. If the pend argument is not NULL, *pend is
1806 set to NULL.
1807
1808- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1809 for the attribute name. See note on getattr() above.
1810
1811- A few bug fixes to argument processing for Unicode.
1812 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1813 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1814 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001815 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001816
1817- Py_BuildValue accepts B format (for bgen-generated code).
1818
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001819
Jeremy Hylton1b618592000-09-26 05:32:36 +00001820Internals
1821
1822- On Unix, fix code for finding Python installation directory so that
1823 it works when argv[0] is a relative path.
1824
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001825- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001826 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001827 rather than by generating a copy of the object.
1828
Tim Peters482c0212000-09-26 06:33:09 +00001829- Several of the internal Unicode tables are much smaller now, and
1830 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001831
Jeremy Hylton97693b02000-09-26 17:42:51 +00001832- In the garbage collector: Fixed bug in collection of tuples. Fixed
1833 bug that caused some instances to be removed from the container set
1834 while they were still live. Fixed parsing in gc.set_debug() for
1835 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001836
1837- Fixed refcount problem in instance deallocation that only occurred
1838 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1839
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001840- On Windows, getpythonregpath is now protected against null data in
1841 registry key.
1842
1843- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001844 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001845
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001846
Jeremy Hylton1b618592000-09-26 05:32:36 +00001847Build and platform-specific issues
1848
1849- Better support of GNU Pth via --with-pth configure option.
1850
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001851- Python/C API now properly exposed to dynamically-loaded extension
1852 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001853
1854- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1855 Don't define MS_SYNC to be zero when it is undefined. Added missing
1856 prototypes in posixmodule.c.
1857
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001858- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001859 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001860
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001861- Fix largefile support on older NetBSD systems and OpenBSD by adding
1862 define for TELL64.
1863
1864
1865Tools and other miscellany
1866
1867- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
1868
1869- freeze: The modulefinder now works with 2.0 opcodes.
1870
Tim Petersa3a3a032000-11-30 05:22:44 +00001871- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001872 Move hackery of sys.argv until after the Tk instance has been
1873 created, which allows the application-specific Tkinter
1874 initialization to be executed if present; also pass an explicit
1875 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00001876
Jeremy Hylton1b618592000-09-26 05:32:36 +00001877
1878What's new in 2.0 beta 1?
1879=========================
1880
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001881Source Incompatibilities
1882------------------------
1883
1884None. Note that 1.6 introduced several incompatibilities with 1.5.2,
1885such as single-argument append(), connect() and bind(), and changes to
1886str(long) and repr(float).
1887
1888
1889Binary Incompatibilities
1890------------------------
1891
1892- Third party extensions built for Python 1.5.x or 1.6 cannot be used
1893with Python 2.0; these extensions will have to be rebuilt for Python
18942.0.
1895
1896- On Windows, attempting to import a third party extension built for
1897Python 1.5.x or 1.6 results in an immediate crash; there's not much we
1898can do about this. Check your PYTHONPATH environment variable!
1899
1900- Python bytecode files (*.pyc and *.pyo) are not compatible between
1901releases.
1902
1903
1904Overview of Changes Since 1.6
1905-----------------------------
1906
1907There are many new modules (including brand new XML support through
1908the xml package, and i18n support through the gettext module); a list
1909of all new modules is included below. Lots of bugs have been fixed.
1910
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001911The process for making major new changes to the language has changed
1912since Python 1.6. Enhancements must now be documented by a Python
1913Enhancement Proposal (PEP) before they can be accepted.
1914
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001915There are several important syntax enhancements, described in more
1916detail below:
1917
1918 - Augmented assignment, e.g. x += 1
1919
1920 - List comprehensions, e.g. [x**2 for x in range(10)]
1921
1922 - Extended import statement, e.g. import Module as Name
1923
1924 - Extended print statement, e.g. print >> file, "Hello"
1925
1926Other important changes:
1927
1928 - Optional collection of cyclical garbage
1929
Jeremy Hylton24c3d602000-09-05 19:36:26 +00001930Python Enhancement Proposal (PEP)
1931---------------------------------
1932
1933PEP stands for Python Enhancement Proposal. A PEP is a design
1934document providing information to the Python community, or describing
1935a new feature for Python. The PEP should provide a concise technical
1936specification of the feature and a rationale for the feature.
1937
1938We intend PEPs to be the primary mechanisms for proposing new
1939features, for collecting community input on an issue, and for
1940documenting the design decisions that have gone into Python. The PEP
1941author is responsible for building consensus within the community and
1942documenting dissenting opinions.
1943
1944The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001945
1946Augmented Assignment
1947--------------------
1948
1949This must have been the most-requested feature of the past years!
1950Eleven new assignment operators were added:
1951
Guido van Rossume905e952000-09-05 12:42:46 +00001952 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001953
1954For example,
1955
1956 A += B
1957
1958is similar to
1959
1960 A = A + B
1961
1962except that A is evaluated only once (relevant when A is something
1963like dict[index].attr).
1964
1965However, if A is a mutable object, A may be modified in place. Thus,
1966if A is a number or a string, A += B has the same effect as A = A+B
1967(except A is only evaluated once); but if a is a list, A += B has the
1968same effect as A.extend(B)!
1969
1970Classes and built-in object types can override the new operators in
1971order to implement the in-place behavior; the not-in-place behavior is
1972used automatically as a fallback when an object doesn't implement the
1973in-place behavior. For classes, the method name is derived from the
1974method name for the corresponding not-in-place operator by inserting
1975an 'i' in front of the name, e.g. __iadd__ implements in-place
1976__add__.
1977
1978Augmented assignment was implemented by Thomas Wouters.
1979
1980
1981List Comprehensions
1982-------------------
1983
1984This is a flexible new notation for lists whose elements are computed
1985from another list (or lists). The simplest form is:
1986
1987 [<expression> for <variable> in <sequence>]
1988
Guido van Rossum56db0952000-09-06 23:34:25 +00001989For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001990This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001991
1992You can also add a condition:
1993
1994 [<expression> for <variable> in <sequence> if <condition>]
1995
1996For example, [w for w in words if w == w.lower()] would yield the list
1997of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001998than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001999
2000You can also have nested for loops and more than one 'if' clause. For
2001example, here's a function that flattens a sequence of sequences::
2002
2003 def flatten(seq):
2004 return [x for subseq in seq for x in subseq]
2005
2006 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2007
2008This prints
2009
2010 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2011
2012List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002013Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002014
2015
2016Extended Import Statement
2017-------------------------
2018
2019Many people have asked for a way to import a module under a different
2020name. This can be accomplished like this:
2021
2022 import foo
2023 bar = foo
2024 del foo
2025
2026but this common idiom gets old quickly. A simple extension of the
2027import statement now allows this to be written as follows:
2028
2029 import foo as bar
2030
2031There's also a variant for 'from ... import':
2032
2033 from foo import bar as spam
2034
2035This also works with packages; e.g. you can write this:
2036
2037 import test.regrtest as regrtest
2038
2039Note that 'as' is not a new keyword -- it is recognized only in this
2040context (this is only possible because the syntax for the import
2041statement doesn't involve expressions).
2042
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002043Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002044
2045
2046Extended Print Statement
2047------------------------
2048
2049Easily the most controversial new feature, this extension to the print
2050statement adds an option to make the output go to a different file
2051than the default sys.stdout.
2052
2053For example, to write an error message to sys.stderr, you can now
2054write:
2055
2056 print >> sys.stderr, "Error: bad dog!"
2057
2058As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002059evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002060
2061 print >> None, "Hello world"
2062
2063is equivalent to
2064
2065 print "Hello world"
2066
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002067Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002068
2069
2070Optional Collection of Cyclical Garbage
2071---------------------------------------
2072
2073Python is now equipped with a garbage collector that can hunt down
2074cyclical references between Python objects. It's no replacement for
2075reference counting; in fact, it depends on the reference counts being
2076correct, and decides that a set of objects belong to a cycle if all
2077their reference counts can be accounted for from their references to
2078each other. This devious scheme was first proposed by Eric Tiedemann,
2079and brought to implementation by Neil Schemenauer.
2080
2081There's a module "gc" that lets you control some parameters of the
2082garbage collection. There's also an option to the configure script
2083that lets you enable or disable the garbage collection. In 2.0b1,
2084it's on by default, so that we (hopefully) can collect decent user
2085experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002086performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002087off by default in the final 2.0 release.
2088
2089
2090Smaller Changes
2091---------------
2092
2093A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2094map(None, seq1, seq2, ...) when the sequences have the same length;
2095i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2096the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002097zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002098
2099sys.version_info is a tuple (major, minor, micro, level, serial).
2100
2101Dictionaries have an odd new method, setdefault(key, default).
2102dict.setdefault(key, default) returns dict[key] if it exists; if not,
2103it sets dict[key] to default and returns that value. Thus:
2104
2105 dict.setdefault(key, []).append(item)
2106
2107does the same work as this common idiom:
2108
2109 if not dict.has_key(key):
2110 dict[key] = []
2111 dict[key].append(item)
2112
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002113There are two new variants of SyntaxError that are raised for
2114indentation-related errors: IndentationError and TabError.
2115
2116Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2117escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002118
2119The limits on the size of expressions and file in Python source code
2120have been raised from 2**16 to 2**32. Previous versions of Python
2121were limited because the maximum argument size the Python VM accepted
2122was 2**16. This limited the size of object constructor expressions,
2123e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2124limit was raised thanks to a patch by Charles Waldman that effectively
2125fixes the problem. It is now much more likely that you will be
2126limited by available memory than by an arbitrary limit in Python.
2127
2128The interpreter's maximum recursion depth can be modified by Python
2129programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2130limit is the maximum number of recursive calls that can be made by
2131Python code. The limit exists to prevent infinite recursion from
2132overflowing the C stack and causing a core dump. The default value is
21331000. The maximum safe value for a particular platform can be found
2134by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002135
2136New Modules and Packages
2137------------------------
2138
2139atexit - for registering functions to be called when Python exits.
2140
2141imputil - Greg Stein's alternative API for writing custom import
2142hooks.
2143
2144pyexpat - an interface to the Expat XML parser, contributed by Paul
2145Prescod.
2146
2147xml - a new package with XML support code organized (so far) in three
2148subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2149would fill a volume. There's a special feature whereby a
2150user-installed package named _xmlplus overrides the standard
2151xmlpackage; this is intended to give the XML SIG a hook to distribute
2152backwards-compatible updates to the standard xml package.
2153
2154webbrowser - a platform-independent API to launch a web browser.
2155
2156
Guido van Rossume905e952000-09-05 12:42:46 +00002157Changed Modules
2158---------------
2159
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002160array -- new methods for array objects: count, extend, index, pop, and
2161remove
2162
2163binascii -- new functions b2a_hex and a2b_hex that convert between
2164binary data and its hex representation
2165
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002166calendar -- Many new functions that support features including control
2167over which day of the week is the first day, returning strings instead
2168of printing them. Also new symbolic constants for days of week,
2169e.g. MONDAY, ..., SUNDAY.
2170
2171cgi -- FieldStorage objects have a getvalue method that works like a
2172dictionary's get method and returns the value attribute of the object.
2173
2174ConfigParser -- The parser object has new methods has_option,
2175remove_section, remove_option, set, and write. They allow the module
2176to be used for writing config files as well as reading them.
2177
2178ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002179optionally support the RFC 959 REST command.
2180
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002181gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002182
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002183httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2184the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002185
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002186locale -- implement getdefaultlocale for Win32 and Macintosh
2187
2188marshal -- no longer dumps core when marshaling deeply nested or
2189recursive data structures
2190
2191os -- new functions isatty, seteuid, setegid, setreuid, setregid
2192
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002193os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2194support under Unix.
2195
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002196os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002197
2198os.path -- fix semantics of os.path.commonprefix
2199
2200smtplib -- support for sending very long messages
2201
2202socket -- new function getfqdn()
2203
2204readline -- new functions to read, write and truncate history files.
2205The readline section of the library reference manual contains an
2206example.
2207
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002208select -- add interface to poll system call
2209
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002210shutil -- new copyfileobj function
2211
2212SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2213HTTP server.
2214
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002215Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002216
2217urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002218e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002219
2220whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002221
2222
2223Obsolete Modules
2224----------------
2225
2226None. However note that 1.6 made a whole slew of modules obsolete:
2227stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2228poly, zmod, strop, util, whatsound.
2229
2230
2231Changed, New, Obsolete Tools
2232----------------------------
2233
Tim Peters8b092332000-09-05 20:15:25 +00002234None.
Guido van Rossume905e952000-09-05 12:42:46 +00002235
2236
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002237C-level Changes
2238---------------
2239
2240Several cleanup jobs were carried out throughout the source code.
2241
2242All C code was converted to ANSI C; we got rid of all uses of the
2243Py_PROTO() macro, which makes the header files a lot more readable.
2244
2245Most of the portability hacks were moved to a new header file,
2246pyport.h; several other new header files were added and some old
2247header files were removed, in an attempt to create a more rational set
2248of header files. (Few of these ever need to be included explicitly;
2249they are all included by Python.h.)
2250
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002251Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002252and Win64, especially for the new Intel Itanium processor. Mick also
2253added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002254
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002255The C APIs to return an object's size have been update to consistently
2256use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2257previous versions, the abstract interfaces used PyXXX_Length and the
2258concrete interfaces used PyXXX_Size. The old names,
2259e.g. PyObject_Length, are still available for backwards compatibility
2260at the API level, but are deprecated.
2261
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002262The PyOS_CheckStack function has been implemented on Windows by
2263Fredrik Lundh. It prevents Python from failing with a stack overflow
2264on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002265
2266The GC changes resulted in creation of two new slots on object,
2267tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002268the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002269
2270The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002271C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002272
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002273PyErr_Format has been updated to automatically calculate the size of
2274the buffer needed to hold the formatted result string. This change
2275prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002276
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002277New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002278
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002279PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2280that are the same as their non-Ex counterparts except they take an
2281extra flag argument that tells them to close the file when done.
2282
2283XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002284
Tim Peters8b092332000-09-05 20:15:25 +00002285
2286Windows Changes
2287---------------
2288
2289New popen2/popen3/peopen4 in os module (see Changed Modules above).
2290
2291os.popen is much more usable on Windows 95 and 98. See Microsoft
2292Knowledge Base article Q150956. The Win9x workaround described there
2293is implemented by the new w9xpopen.exe helper in the root of your
2294Python installation. Note that Python uses this internally; it is not
2295a standalone program.
2296
2297Administrator privileges are no longer required to install Python
2298on Windows NT or Windows 2000. If you have administrator privileges,
2299Python's registry info will be written under HKEY_LOCAL_MACHINE.
2300Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002301under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002302uses of Python, but will prevent some advanced uses from working
2303(for example, running a Python script as an NT service, or possibly
2304from CGI).
2305
2306[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2307installer; instead, it installs the needed Tcl/Tk files directly in the
2308Python directory. If you already have a Tcl/Tk installation, this
2309wastes some disk space (about 4 Megs) but avoids problems with
2310conflicting Tcl/Tk installations, and makes it much easier for Python
2311to ensure that Tcl/Tk can find all its files.
2312
2313[This was new in 1.6] The Windows installer now installs by default in
2314\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2315
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002316
2317Updates to the changes between 1.5.2 and 1.6
2318--------------------------------------------
2319
2320The 1.6 NEWS file can't be changed after the release is done, so here
2321is some late-breaking news:
2322
2323New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2324and changes to getlocale() and setlocale().
2325
2326The new module is now enabled per default.
2327
2328It is not true that the encodings codecs cannot be used for normal
2329strings: the string.encode() (which is also present on 8-bit strings
2330!) allows using them for 8-bit strings too, e.g. to convert files from
2331cp1252 (Windows) to latin-1 or vice-versa.
2332
2333Japanese codecs are available from Tamito KAJIYAMA:
2334http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2335
2336
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002337======================================================================