blob: c22cf245649d1fc42652a65754678dbad1d057dc [file] [log] [blame]
Tim Petersb07352e2001-09-08 01:25:47 +00001What's New in Python 2.2a4?
2===========================
3
4Core
5
Martin v. Löwis2777c022001-09-19 13:47:32 +00006- PyFile_WriteObject now passes Unicode object to the file's write
7 method. As a result, all file-like object which may be the target
8 of a print statement must support Unicode objects, i.e. they must
9 at least convert them into ASCII strings.
10
Tim Peters59c9a642001-09-13 05:38:56 +000011- The builtin file type can be subclassed now. In the usual pattern,
12 "file" is the name of the builtin type, and file() is a new builtin
13 constructor, with the same signature as the builtin open() function.
14 file() is now the preferred way to open a file.
15
Guido van Rossum624c8af2001-09-18 15:21:04 +000016- In 2.2a3, __new__ would only see sequential arguments passed to the
17 type in a constructor call; __init__ would see both sequential and
18 positional arguments. This made no sense whatsoever any more, so
19 now both __new__ and __init__ see all arguments.
20
Tim Peters1f47d112001-09-12 23:40:29 +000021- In 2.2a3, hash() applied to an instance of a subclass of str or unicode
22 always returned 0. This has been repaired.
23
24- In 2.2a3, an operation on an instance of a subclass of an immutable type
25 (int, long, float, complex, tuple, str, unicode), where the subtype
26 didn't override the operation (and so the operation was handled by the
27 builtin type), could return that instance instead a value of the base
28 type. For example, if s was of a str sublass type, s[:] returned s
29 as-is. Now it returns a str with the same value as s.
30
Guido van Rossum624c8af2001-09-18 15:21:04 +000031- Applications using Jim Fulton's ExtensionClass module can now safely
32 be used with Python 2.2. In particular, Zope 2.4.1 now works with
33 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
34 examples also work again.
35
36- Thread scheduling on Solaris should be improved; it is no longer
37 necessary to insert a small sleep at the start of a thread in order
38 to let other runnable threads be scheduled.
39
Tim Petersb07352e2001-09-08 01:25:47 +000040Library
41
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +000042- The codecs module has grown four new helper APIs to access
43 builtin codecs: getencoder(), getdecoder(), getreader(),
44 getwriter().
45
Guido van Rossum624c8af2001-09-18 15:21:04 +000046- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
47 simplifies writing XML RPC servers.
48
49- os.path.realpath(): a new function that returns the absoute pathname
50 after interpretation of symbolic links. On non-Unix systems, this
51 is an alias for os.path.abspath().
52
Tim Peters16a77ad2001-09-08 04:00:12 +000053- operator.indexOf() (PySequence_Index() in the C API) now works with any
54 iterable object.
55
Guido van Rossum624c8af2001-09-18 15:21:04 +000056- smtplib now supports various authentication and security features of
57 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +000058
Guido van Rossum624c8af2001-09-18 15:21:04 +000059- hmac: a new module implementing keyed hashing for message
60 authentication.
61
62- mimetypes now recognizes more extensions and file types. At the
63 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +000064
Guido van Rossum624c8af2001-09-18 15:21:04 +000065- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +000066 Python 2.2 bytecode generation. It has also been promoted from a
67 Tool to a standard library package. (Tools/compiler still exists as
68 a sample driver.)
69
70- pydoc and inspect are now aware of new-style classes;
71 e.g. help(list) at the interactive prompt now shows proper
72 documentation for all operations on list objects.
73
74Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +000075
Tim Petersb07352e2001-09-08 01:25:47 +000076Build
77
Guido van Rossum624c8af2001-09-18 15:21:04 +000078- Large file support (LFS) is now automatic when the platform supports
79 it; no more manual configuration tweaks are needed. On Linux, at
80 least, it's possible to have a system whose C library supports large
81 files but whose kernel doesn't; in this case, large file support is
82 still enabled but doesn't do you any good unless you upgrade your
83 kernel or share your Python executable with another system whose
84 kernel has large file support.
85
86- The configure script now supplies plausible defaults in a
87 cross-compilation environment. This doesn't mean that the supplied
88 values are always correct, or that cross-compilation now works
89 flawlessly -- but it's a first step (and it shuts up most of
90 autoconf's warnings about AC_TRY_RUN).
91
92- The Unix build is now a bit less chatty, courtesy of the parser
93 generator. The build is completely silent (except for errors) when
94 using "make -s", thanks to a -q option to setup.py.
95
Tim Petersb07352e2001-09-08 01:25:47 +000096C API
97
Guido van Rossum624c8af2001-09-18 15:21:04 +000098- The "structmember" API now supports some new flag bits to deny read
99 and/or write access to attributes in restricted execution mode.
100
Tim Petersb07352e2001-09-08 01:25:47 +0000101New platforms
102
Guido van Rossum624c8af2001-09-18 15:21:04 +0000103- Compaq's iPAQ handheld, running the "familiar" Linux distribution
104 (http://familiar.handhelds.org).
105
Tim Petersb07352e2001-09-08 01:25:47 +0000106Tests
107
108Windows
109
Guido van Rossum624c8af2001-09-18 15:21:04 +0000110- Large file support now also works for files > 4GB, on filesystems
111 that support it (NTFS under Windows 2000).
112
Tim Petersb07352e2001-09-08 01:25:47 +0000113
Tim Petersedc99312001-08-22 21:36:50 +0000114What's New in Python 2.2a3?
115===========================
116
117Core
118
Tim Peters9fffa3e2001-09-04 05:14:19 +0000119- Conversion of long to float now raises OverflowError if the long is too
120 big to represent as a C double.
121
Tim Peters32f453e2001-09-03 08:35:41 +0000122- The 3-argument builtin pow() no longer allows a third non-None argument
123 if either of the first two arguments is a float, or if both are of
124 integer types and the second argument is negative (in which latter case
125 the arguments are converted to float, so this is really the same
126 restriction).
127
Tim Peters5d2b77c2001-09-03 05:47:38 +0000128- The builtin dir() now returns more information, and sometimes much
129 more, generally naming all attributes of an object, and all attributes
130 reachable from the object via its class, and from its class's base
131 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
132 an empty list. In 2.2a3,
133
134 >>> dir([])
135 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
136 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
137 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
138 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
139 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
140 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
141 'reverse', 'sort']
142
143 dir(module) continues to return only the module's attributes, though.
144
Tim Petersbdee63f2001-09-02 03:40:59 +0000145- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000146 than raising OverflowError. This is a partial implementation of PEP
147 237. You can use -Wdefault::OverflowWarning to enable a warning for
148 this situation, and -Werror::OverflowWarning to revert to the old
149 OverflowError exception.
150
Guido van Rossum61c345f2001-09-04 03:26:15 +0000151- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000152 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000153 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
154 -Qold, meaning the / operator has its classic meaning and no
155 warnings are issued. Using -Qwarn issues a run-time warning about
156 all uses of classic division for int and long arguments; -Qwarnall
157 also warns about classic division for float and complex arguments
158 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
159 new division by default, but only in the __main__ module. You can
160 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
161 __main__ module new division, and warns about classic division
162 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000163
Tim Petersbdee63f2001-09-02 03:40:59 +0000164- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000165 long, float, str, unicode, and tuple. (The types complex, list and
166 dictionary can also be subclassed; this was introduced earlier.)
167 Note that restrictions apply when subclassing immutable built-in
168 types: you can only affect the value of the instance by overloading
169 __new__. You can add mutable attributes, and the subclass instances
170 will have a __dict__ attribute, but you cannot change the "value"
171 (as implemented by the base class) of an immutable subclass instance
172 once it is created.
173
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000174- The dictionary constructor now takes an optional argument, a
175 mapping-like object, and initializes the dictionary from its
176 (key, value) pairs.
177
Tim Petersbdee63f2001-09-02 03:40:59 +0000178- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000179 "cooperative super calls" in a multiple inheritance setting. For an
180 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
181
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000182- A new built-in type, property, has been added. This enables the
183 creation of "properties". These are attributes implemented by
184 getter and setter functions (or only one of these for read-only or
185 write-only attributes), without the need to override __getattr__.
186 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000187
Tim Petersbdee63f2001-09-02 03:40:59 +0000188- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000189 liberalized, to allow leading zeroes. Examples of literals now
190 legal that were SyntaxErrors before:
191
192 00.0 0e3 0100j 07.5 00000000000000000008.
193
Tim Petersbdee63f2001-09-02 03:40:59 +0000194- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000195 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
196
Tim Petersedc99312001-08-22 21:36:50 +0000197Library
198
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000199- telnetlib includes symbolic names for the options, and support for
200 setting an option negotiation callback.
201
Tim Petersa40c7932001-09-05 22:36:56 +0000202- The new C standard no longer requires that math libraries set errno to
203 ERANGE on overflow. For platform libraries that exploit this new
204 freedom, Python's overflow-checking was wholly broken. A new overflow-
205 checking scheme attempts to repair that, but may not be reliable on all
206 platforms (C doesn't seem to provide anything both useful and portable
207 in this area anymore).
208
Martin v. Löwis44f86962001-09-05 13:44:54 +0000209- Asynchronous timeout actions are available through the new class
210 threading.Timer.
211
Tim Peters78526162001-09-05 00:53:45 +0000212- math.log and math.log10 now return sensible results for even huge
213 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
214
Tim Petersbdee63f2001-09-02 03:40:59 +0000215- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000216 currently held. See the docs for the imp module.
217
Tim Petersbdee63f2001-09-02 03:40:59 +0000218- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000219 dumps containing ints written on platforms where Python ints are 8 bytes.
220 When read on a box where Python ints are 4 bytes, such values are
221 converted to Python longs.
222
Tim Petersbdee63f2001-09-02 03:40:59 +0000223- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000224 code objects is no longer allowed. This plugs a security hole.
225
Steve Purcell6091cd62001-09-06 16:05:17 +0000226- unittest.TestResult instances no longer store references to tracebacks
227 generated by test failures. This prevents unexpected dangling references
228 to objects that should be garbage collected between tests.
229
Tim Petersedc99312001-08-22 21:36:50 +0000230Tools
231
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000232- Tools/scripts/fixdiv.py has been added which can be used to fix
233 division operators as per PEP 238.
234
Tim Petersedc99312001-08-22 21:36:50 +0000235Build
236
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000237- If you are an adventurous person using Mac OS X you may want to look at
238 Mac/OSX. There is a Makefile there that will build Python as a real Mac
239 application, which can be used for experimenting with Carbon or Cocoa.
240 Discussion of this on pythonmac-sig, please.
241
Tim Peters7eea37e2001-09-04 22:08:56 +0000242C API
243
244- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000245
Tim Peters9fffa3e2001-09-04 05:14:19 +0000246- Note that PyLong_AsDouble can fail! This has always been true, but no
247 callers checked for it. It's more likely to fail now, because overflow
248 errors are properly detected now. The proper way to check:
249
250 double x = PyLong_AsDouble(some_long_object);
251 if (x == -1.0 && PyErr_Occurred()) {
252 /* The conversion failed. */
253 }
254
Tim Petersbdee63f2001-09-02 03:40:59 +0000255- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000256 compile but will not participate in GC. To upgrade an extension
257 module:
258
259 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000260
Neil Schemenauer4042c692001-08-30 15:38:01 +0000261 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
262 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000263
Neil Schemenauer4042c692001-08-30 15:38:01 +0000264 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
265 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000266
Neil Schemenauer4042c692001-08-30 15:38:01 +0000267 - remove PyGC_HEAD_SIZE from object size calculations
268
269 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
270
Tim Petersbdee63f2001-09-02 03:40:59 +0000271- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000272 These can be used safely to construct string objects from a
273 sprintf-style format string (similar to the format string supported
274 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000275
Tim Petersedc99312001-08-22 21:36:50 +0000276New platforms
277
Tim Petersb7da0902001-09-02 23:01:43 +0000278- Stephen Hansen contributed patches sufficient to get a clean compile
279 under Borland C (Windows), but he reports problems running it and ran
280 out of time to complete the port. Volunteers? Expect a MemoryError
281 when importing the types module; this is probably shallow, and
282 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000283
Tim Petersedc99312001-08-22 21:36:50 +0000284Tests
285
286Windows
287
Tim Peters6e13a562001-09-06 00:32:15 +0000288- Large file support is now enabled on Win32 platforms as well as on
289 Win64. This means that, for example, you can use f.tell() and f.seek()
290 to manipulate files larger than 2 gigabytes (provided you have enough
291 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000292 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
293 filesize limit, and large file support makes no difference there.
294 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
295 NTFS has no practical limit on file size, and files of any size can be
296 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000297
Tim Petersbdee63f2001-09-02 03:40:59 +0000298- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000299 points to command.com (patch from Brian Quinlan).
300
Tim Petersedc99312001-08-22 21:36:50 +0000301
Tim Peters20f51a72001-07-21 02:31:40 +0000302What's New in Python 2.2a2?
303===========================
304
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000305Build
306
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000307- Tim Peters developed a brand new Windows installer using Wise 8.1,
308 generously donated to us by Wise Solutions.
309
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000310- configure supports a new option --enable-unicode, with the values
311 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
312 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000313
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000314- A new configure option --enable-framework builds a Mac OS X framework,
315 which "make frameworkinstall" will install. This provides a starting
316 point for more mac-like functionality, join pythonmac-sig@python.org
317 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000318
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000319- The NeXT platform is no longer supported.
320
321- The `new' module is now statically linked.
322
Tim Peters0afb6092001-08-15 06:06:44 +0000323Tools
324
325- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000326 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000327 the module docstring for details.
328
Tim Peters20f51a72001-07-21 02:31:40 +0000329Tests
330
Tim Peters5e824c32001-08-12 22:25:01 +0000331- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000332 platforms, allowing to give clearer test result output. regrtest
333 also has optional --use/-u switch to run normally disabled tests
334 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000335
Tim Peters20f51a72001-07-21 02:31:40 +0000336- Several new tests in the standard test suite, with special thanks to
337 Nick Mathewson.
338
339Core
340
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000341- The floor division operator // has been added as outlined in PEP
342 238. The / operator still provides classic division (and will until
343 Python 3.0) unless "from __future__ import division" is included, in
344 which case the / operator will provide true division. The operator
345 module provides truediv() and floordiv() functions. Augmented
346 assignment variants are included, as are the equivalent overloadable
347 methods and C API methods. See the PEP for a full discussion:
348 <http://python.sf.net/peps/pep-0238.html>
349
Tim Peters6cd6a822001-08-17 22:11:27 +0000350- Future statements are now effective in simulated interactive shells
351 (like IDLE). This should "just work" by magic, but read Michael
352 Hudson's "Future statements in simulated shells" PEP 264 for full
353 details: <http://python.sf.net/peps/pep-0264.html>.
354
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000355- The type/class unification (PEP 252-253) was integrated into the
356 trunk and is not so tentative any more (the exact specification of
357 some features is still tentative). A lot of work has done on fixing
358 bugs and adding robustness and features (performance still has to
359 come a long way).
360
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000361- Warnings about a mismatch in the Python API during extension import
362 now use the Python warning framework (which makes it possible to
363 write filters for these warnings).
364
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000365- A function's __dict__ (aka func_dict) will now always be a
366 dictionary. It used to be possible to delete it or set it to None,
367 but now both actions raise TypeErrors. It is still legal to set it
368 to a dictionary object. Getting func.__dict__ before any attributes
369 have been assigned now returns an empty dictionary instead of None.
370
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000371- A new command line option, -E, was added which disables the use of
372 all environment variables, or at least those that are specifically
373 significant to Python. Usually those have a name starting with
374 "PYTHON". This was used to fix a problem where the tests fail if
375 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
376 older distribution.
377
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000378Library
379
Tim Peters5e824c32001-08-12 22:25:01 +0000380- New class Differ and new functions ndiff() and restore() in difflib.py.
381 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000382 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000383
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000384- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
385 value using the minimal quoting required for the value; more
386 reliable than using xml.sax.saxutils.escape() for attribute values.
387
388- Readline completion support for cmd.Cmd was added.
389
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000390- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
391
392- Added function threading.BoundedSemaphore()
393
394- Added Ka-Ping Yee's cgitb.py module.
395
396- The `new' module now exposes the CO_xxx flags.
397
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000398New platforms
399
400C API
401
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000402- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
403 which provide a cross-platform implementations for the
404 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
405 the standard sprintf() and vsprintf() C lib APIs, these versions
406 apply bounds checking on the used buffer which enhances protection
407 against buffer overruns.
408
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000409- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000410 and extensions using different Unicode widths is rendered next to
411 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000412 will result in an ImportError. Unicode extensions writers must make
413 sure to check the Unicode width compatibility in their extensions by
414 using at least one of the mangled Unicode APIs in the extension.
415
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000416- Two new flags METH_NOARGS and METH_O are available in method definition
417 tables to simplify implementation of methods with no arguments and a
418 single untyped argument. Calling such methods is more efficient than
419 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
420 deprecated.
421
Tim Petersc1731372001-08-04 08:12:36 +0000422Windows
423
424- "import module" now compiles module.pyw if it exists and nothing else
425 relevant is found.
426
Tim Peters20f51a72001-07-21 02:31:40 +0000427
Guido van Rossum55a78992001-07-17 17:22:32 +0000428What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000429===========================
430
431Core
Tim Petersa814db52001-05-14 07:05:58 +0000432
Tim Peters6d6c1a32001-08-02 04:15:00 +0000433- TENTATIVELY, a large amount of code implementing much of what's
434 described in PEP 252 (Making Types Look More Like Classes) and PEP
435 253 (Subtyping Built-in Types) was added. This will be released
436 with Python 2.2a1. Documentation will be provided separately
437 through http://www.python.org/2.2/. The purpose of releasing this
438 with Python 2.2a1 is to test backwards compatibility. It is
439 possible, though not likely, that a decision is made not to release
440 this code as part of 2.2 final, if any serious backwards
441 incompapatibilities are found during alpha testing that cannot be
442 repaired.
443
Guido van Rossum55a78992001-07-17 17:22:32 +0000444- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000445 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000446 more 'yield' statements. See PEP 255. Since this adds a new
447 keyword to the language, this feature must be enabled by including a
448 future statement: "from __future__ import generators" (see PEP 236).
449 Generators will become a standard feature in a future release
450 (probably 2.3). Without this future statement, 'yield' remains an
451 ordinary identifier, but a warning is issued each time it is used.
452 (These warnings currently don't conform to the warnings framework of
453 PEP 230; we intend to fix this in 2.2a2.)
454
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000455- The UTF-16 codec was modified to be more RFC compliant. It will now
456 only remove BOM characters at the start of the string and then
457 only if running in native mode (UTF-16-LE and -BE won't remove a
458 leading BMO character).
459
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000460- Strings now have a new method .decode() to complement the already
461 existing .encode() method. These two methods provide direct access
462 to the corresponding decoders and encoders of the registered codecs.
463
464 To enhance the usability of the .encode() method, the special
465 casing of Unicode object return values was dropped (Unicode objects
466 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000467
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000468 Both methods will now return whatever the codec in charge of the
469 requested encoding returns as object, e.g. Unicode codecs will
470 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
471 will return u"äöü"). This enables codec writer to create codecs
472 for various simple to use conversions.
473
474 New codecs were added to demonstrate these new features (the .encode()
475 and .decode() columns indicate the type of the returned objects):
476
477 Name | .encode() | .decode() | Description
478 ----------------------------------------------------------------------
479 uu | string | string | UU codec (e.g. for email)
480 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000481 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000482 zlib | string | string | zlib compression
483 hex | string | string | 2-byte hex codec
484 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
485
Mark Hammond2a0af792001-05-14 03:09:36 +0000486- Some operating systems now support the concept of a default Unicode
487 encoding for file system operations. Notably, Windows supports 'mbcs'
488 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000489 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000490 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000491
492 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000493 functions that return filenames (such as os.listdir()) to return Python
494 string objects pre-encoded using the default file system encoding for
495 the platform. As this encoding is likely to be different from Python's
496 default encoding, converting this name to a Unicode object before passing
497 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000498 would attempt to use its default encoding (generally ASCII) rather than
499 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000500
Tim Petersa814db52001-05-14 07:05:58 +0000501 In general, this change simply removes surprises when working with
502 Unicode and the file system, making these operations work as you expect,
503 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000504 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000505
Tim Peters61dff2b2001-05-08 15:43:37 +0000506- Float (and complex) literals in source code were evaluated to full
507 precision only when running from a .py file; the same code loaded from a
508 .pyc (or .pyo) file could suffer numeric differences starting at about the
509 12th significant decimal digit. For example, on a machine with IEEE-754
510 floating arithmetic,
511
512 x = 9007199254740992.0
513 print long(x)
514
515 printed 9007199254740992 if run directly from .py, but 9007199254740000
516 if from a compiled (.pyc or .pyo) file. This was due to marshal using
517 str(float) instead of repr(float) when building code objects. marshal
518 now uses repr(float) instead, which should reproduce floats to full
519 machine precision (assuming the platform C float<->string I/O conversion
520 functions are of good quality).
521
522 This may cause floating-point results to change in some cases, and
523 usually for the better, but may also cause numerically unstable
524 algorithms to break.
525
Tim Peters2f228e72001-05-13 00:19:31 +0000526- The implementation of dicts suffers fewer collisions, which has speed
527 benefits. However, the order in which dict entries appear in dict.keys(),
528 dict.values() and dict.items() may differ from previous releases for a
529 given dict. Nothing is defined about this order, so no program should
530 rely on it. Nevertheless, it's easy to write test cases that rely on the
531 order by accident, typically because of printing the str() or repr() of a
532 dict to an "expected results" file. See Lib/test/test_support.py's new
533 sortdict(dict) function for a simple way to display a dict in sorted
534 order.
535
Tim Peters7a3bfc32001-06-12 01:22:22 +0000536- Many other small changes to dicts were made, resulting in faster
537 operation along the most common code paths.
538
Guido van Rossum10315822001-05-01 20:54:30 +0000539- Dictionary objects now support the "in" operator: "x in dict" means
540 the same as dict.has_key(x).
541
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000542- The update() method of dictionaries now accepts generic mapping
543 objects. Specifically the argument object must support the .keys()
544 and __getitem__() methods. This allows you to say, for example,
545 {}.update(UserDict())
546
Guido van Rossum10315822001-05-01 20:54:30 +0000547- Iterators were added; this is a generalized way of providing values
548 to a for loop. See PEP 234. There's a new built-in function iter()
549 to return an iterator. There's a new protocol to get the next value
550 from an iterator using the next() method (in Python) or the
551 tp_iternext slot (in C). There's a new protocol to get iterators
552 using the __iter__() method (in Python) or the tp_iter slot (in C).
553 Iterating (i.e. a for loop) over a dictionary generates its keys.
554 Iterating over a file generates its lines.
555
Tim Petersf553f892001-05-01 20:45:31 +0000556- The following functions were generalized to work nicely with iterator
557 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000558 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000559 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
560 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000561 join() method of strings
562 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000563 'x in y' and 'x not in y' (PySequence_Contains() in C API)
564 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000565 right-hand side of assignment statements with multiple targets, such as
566 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000567
Tim Petersd85e1022001-05-11 21:51:48 +0000568- Accessing module attributes is significantly faster (for example,
569 random.random or os.path or yourPythonModule.yourAttribute).
570
Tim Peterse63415e2001-05-08 04:38:29 +0000571- Comparing dictionary objects via == and != is faster, and now works even
572 if the keys and values don't support comparisons other than ==.
573
Tim Peters95bf9392001-05-10 08:32:44 +0000574- Comparing dictionaries in ways other than == and != is slower: there were
575 insecurities in the dict comparison implementation that could cause Python
576 to crash if the element comparison routines for the dict keys and/or
577 values mutated the dicts. Making the code bulletproof slowed it down.
578
Tim Peterseb28ef22001-06-02 05:27:19 +0000579- Collisions in dicts are resolved via a new approach, which can help
580 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000581 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000582 faster now. Thanks to Christian Tismer for pointing out the cause and
583 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000584
Tim Peters52e155e2001-06-16 05:42:57 +0000585- repr() is much faster for large containers (dict, list, tuple).
586
587
Tim Petersa814db52001-05-14 07:05:58 +0000588Library
589
Fred Drake960fdf92001-07-20 18:38:26 +0000590- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
591 were added to the string module. These a locale-indenpendent
592 constants, unlike letters, lowercase, and uppercase. These are now
593 use in appropriate locations in the standard library.
594
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000595- The flags used in dlopen calls can now be configured using
596 sys.setdlopenflags and queried using sys.getdlopenflags.
597
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000598- Fredrik Lundh's xmlrpclib is now a standard library module. This
599 provides full client-side XML-RPC support. In addition,
600 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
601 one asyncore-based). Thanks to Eric Raymond for the documentation.
602
Guido van Rossum643d3912001-07-05 14:46:25 +0000603- The xrange() object is simplified: it no longer supports slicing,
604 repetition, comparisons, efficient 'in' checking, the tolist()
605 method, or the start, stop and step attributes. See PEP 260.
606
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000607- A new function fnmatch.filter to filter lists of file names was added.
608
Barry Warsawffd674d2001-05-22 16:00:10 +0000609- calendar.py uses month and day names based on the current locale.
610
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000611- strop is now *really* obsolete (this was announced before with 1.6),
612 and issues DeprecationWarning when used (except for the four items
613 that are still imported into string.py).
614
Tim Petersa814db52001-05-14 07:05:58 +0000615- Cookie.py now sorts key+value pairs by key in output strings.
616
617- pprint.isrecursive(object) didn't correctly identify recursive objects.
618 Now it does.
619
Tim Peters95b3f782001-05-14 18:39:41 +0000620- pprint functions now much faster for large containers (tuple, list, dict).
621
Tim Peters7b9542a2001-06-10 23:40:19 +0000622- New 'q' and 'Q' format codes in the struct module, corresponding to C
623 types "long long" and "unsigned long long" (on Windows, __int64). In
624 native mode, these can be used only when the platform C compiler supports
625 these types (when HAVE_LONG_LONG is #define'd by the Python config
626 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000627 In standard mode, 'q' and 'Q' are supported on all platforms, and are
628 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000629
Guido van Rossum83213cc2001-06-12 16:48:52 +0000630- The site module installs a new built-in function 'help' that invokes
631 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
632 it displays a message reminding the user to use 'help()' or
633 'help(object)'.
634
Tim Petersa814db52001-05-14 07:05:58 +0000635Tests
636
637- New test_mutants.py runs dict comparisons where the key and value
638 comparison operators mutute the dicts randomly during comparison. This
639 rapidly causes Python to crash under earlier releases (not for the faint
640 of heart: it can also cause Win9x to freeze or reboot!).
641
642- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000643 pprint.isreadable() return sensible results. Also verifies that simple
644 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000645
Tim Peters4324aa32001-05-28 22:30:08 +0000646C API
647
648- Removed the unused last_is_sticky argument from the internal
649 _PyTuple_Resize(). If this affects you, you were cheating.
650
651
Guido van Rossum55a78992001-07-17 17:22:32 +0000652======================================================================
653
654
Guido van Rossumffe13be2001-04-16 18:46:45 +0000655What's New in Python 2.1 (final)?
656=================================
657
658We only changed a few things since the last release candidate, all in
659Python library code:
660
661- A bug in the locale module was fixed that affected locales which
662 define no grouping for numeric formatting.
663
664- A few bugs in the weakref module's implementations of weak
665 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
666 and the test suite was updated to check for these bugs.
667
668- An old bug in the os.path.walk() function (introduced in Python
669 2.0!) was fixed: a non-existent file would cause an exception
670 instead of being ignored.
671
672- Fixed a few bugs in the new symtable module found by Neil Norwitz's
673 PyChecker.
674
675
Guido van Rossum5b08f132001-04-16 02:05:23 +0000676What's New in Python 2.1c2?
677===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000678
Guido van Rossum5b08f132001-04-16 02:05:23 +0000679A flurry of small changes, and one showstopper fixed in the nick of
680time made it necessary to release another release candidate. The list
681here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000682
Guido van Rossum5b08f132001-04-16 02:05:23 +0000683Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000684
Guido van Rossum5b08f132001-04-16 02:05:23 +0000685- Tim discovered a nasty bug in the dictionary code, caused by
686 PyDict_Next() calling dict_resize(), and the GC code's use of
687 PyDict_Next() violating an assumption in dict_items(). This was
688 fixed with considerable amounts of band-aid, but the net effect is a
689 saner and more robust implementation.
690
691- Made a bunch of symbols static that were accidentally global.
692
693Build and Ports
694
695- The setup.py script didn't check for a new enough version of zlib
696 (1.1.3 is needed). Now it does.
697
698- Changed "make clean" target to also remove shared libraries.
699
700- Added a more general warning about the SGI Irix optimizer to README.
701
702Library
703
704- Fix a bug in urllib.basejoin("http://host", "../file.html") which
705 omitted the slash between host and file.html.
706
707- The mailbox module's _Mailbox class contained a completely broken
708 and undocumented seek() method. Ripped it out.
709
710- Fixed a bunch of typos in various library modules (urllib2, smtpd,
711 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
712
713- Fixed a few last-minute bugs in unittest.
714
715Extensions
716
717- Reverted the patch to the OpenSSL code in socketmodule.c to support
718 RAND_status() and the EGD, and the subsequent patch that tried to
719 fix it for pre-0.9.5 versions; the problem with the patch is that on
720 some systems it issues a warning whenever socket is imported, and
721 that's unacceptable.
722
723Tests
724
725- Fixed the pickle tests to work with "import test.test_pickle".
726
727- Tweaked test_locale.py to actually run the test Windows.
728
729- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
730 not "wb" (which is not a valid mode at all).
731
732- Fix pstats browser crashes. Import readline if it exists to make
733 the user interface nicer.
734
735- Add "import thread" to the top of test modules that import the
736 threading module (test_asynchat and test_threadedtempfile). This
737 prevents test failures caused by a broken threading module resulting
738 from a previously caught failed import.
739
740- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
741 needed on some platforms (e.g. Solaris 8) when the tests are run
742 twice in succession.
743
744- Skip rather than fail test_sunaudiodev if no audio device is found.
745
746
747What's New in Python 2.1c1?
748===========================
749
750This list was significantly updated when 2.1c2 was released; the 2.1c1
751release didn't mention most changes that were actually part of 2.1c1:
752
753Legal
754
755- Copyright was assigned to the Python Software Foundation (PSF) and a
756 PSF license (very similar to the CNRI license) was added.
757
758- The CNRI copyright notice was updated to include 2001.
759
760Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000761
Guido van Rossumc9932722001-04-12 02:31:27 +0000762- After a public outcry, assignment to __debug__ is no longer illegal;
763 instead, a warning is issued. It will become illegal in 2.2.
764
Guido van Rossum5b08f132001-04-16 02:05:23 +0000765- Fixed a core dump with "%#x" % 0, and changed the semantics so that
766 "%#x" now always prepends "0x", even if the value is zero.
767
768- Fixed some nits in the bytecode compiler.
769
770- Fixed core dumps when calling certain kinds of non-functions.
771
772- Fixed various core dumps caused by reference count bugs.
773
774Build and Ports
775
776- Use INSTALL_SCRIPT to install script files.
777
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000778- New port: SCO Unixware 7, by Billy G. Allie.
779
Guido van Rossum5b08f132001-04-16 02:05:23 +0000780- Updated RISCOS port.
781
782- Updated BeOS port and notes.
783
784- Various other porting problems resolved.
785
786Library
787
788- The TERMIOS and SOCKET modules are now truly obsolete and
789 unnecessary. Their symbols are incorporated in the termios and
790 socket modules.
791
792- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
793 better tests for pickling.
794
795- threading: make Condition.wait() robust against KeyboardInterrupt.
796
797- zipfile: add support to zipfile to support opening an archive
798 represented by an open file rather than a file name. Fix bug where
799 the archive was not properly closed. Fixed a bug in this bugfix
800 where flush() was called for a read-only file.
801
802- imputil: added an uninstall() method to the ImportManager.
803
804- Canvas: fixed bugs in lower() and tkraise() methods.
805
806- SocketServer: API change (added overridable close_request() method)
807 so that the TCP server can explicitly close the request.
808
809- pstats: Eric Raymond added a simple interactive statistics browser,
810 invoked when the module is run as a script.
811
812- locale: fixed a problem in format().
813
814- webbrowser: made it work when the BROWSER environment variable has a
815 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
816 KDE 2. Fixed some other nits.
817
818- unittest: changes to allow using a different exception than
819 AssertionError, and added a few more function aliases. Some other
820 small changes.
821
822- urllib, urllib2: fixed redirect problems and a coupleof other nits.
823
824- asynchat: fixed a critical bug in asynchat that slipped through the
825 2.1b2 release. Fixed another rare bug.
826
827- Fix some unqualified except: clauses (always a bad code example).
828
829XML
830
831- pyexpat: new API get_version_string().
832
833- Fixed some minidom bugs.
834
835Extensions
836
837- Fixed a core dump in _weakref. Removed the weakref.mapping()
838 function (it adds nothing to the API).
839
840- Rationalized the use of header files in the readline module, to make
841 it compile (albeit with some warnings) with the very recent readline
842 4.2, without breaking for earlier versions.
843
844- Hopefully fixed a buffering problem in linuxaudiodev.
845
846- Attempted a fix to make the OpenSSL support in the socket module
847 work again with pre-0.9.5 versions of OpenSSL.
848
849Tests
850
851- Added a test case for asynchat and asyncore.
852
853- Removed coupling between tests where one test failing could break
854 another.
855
856Tools
857
858- Ping added an interactive help browser to pydoc, fixed some nits
859 in the rest of the pydoc code, and added some features to his
860 inspect module.
861
862- An updated python-mode.el version 4.1 which integrates Ken
863 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
864 much nicer in XEmacs and Emacs. When stepping through your program
865 with pdb, in either the shell window or the *Python* window, the
866 source file and line will be tracked by an arrow. Very cool!
867
868- IDLE: syntax warnings in interactive mode are changed into errors.
869
870- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000871 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000872
873- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000874
Barry Warsaw11e89c72001-04-11 20:37:57 +0000875
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000876What's New in Python 2.1 beta 2?
877================================
878
Guido van Rossum053ae352001-03-22 14:17:21 +0000879(Unlisted are many fixed bugs, more documentation, etc.)
880
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000881Core language, builtins, and interpreter
882
Guido van Rossum053ae352001-03-22 14:17:21 +0000883- The nested scopes work (enabled by "from __future__ import
884 nested_scopes") is completed; in particular, the future now extends
885 into code executed through exec, eval() and execfile(), and into the
886 interactive interpreter.
887
888- When calling a base class method (e.g. BaseClass.__init__(self)),
889 this is now allowed even if self is not strictly spoken a class
890 instance (e.g. when using metaclasses or the Don Beaudry hook).
891
892- Slice objects are now comparable but not hashable; this prevents
893 dict[:] from being accepted but meaningless.
894
895- Complex division is now calculated using less braindead algorithms.
896 This doesn't change semantics except it's more likely to give useful
897 results in extreme cases. Complex repr() now uses full precision
898 like float repr().
899
900- sgmllib.py now calls handle_decl() for simple <!...> declarations.
901
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000902- It is illegal to assign to the name __debug__, which is set when the
903 interpreter starts. It is effectively a compile-time constant.
904
905- A warning will be issued if a global statement for a variable
906 follows a use or assignment of that variable.
907
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000908Standard library
909
Guido van Rossum053ae352001-03-22 14:17:21 +0000910- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
911 inspired by JUnit), is now part of the standard library. You now
912 have a choice of two testing frameworks: unittest requires you to
913 write testcases as separate code, doctest gathers them from
914 docstrings. Both approaches have their advantages and
915 disadvantages.
916
917- A new module Tix was added, which wraps the Tix extension library
918 for Tk. With that module, it is not necessary to statically link
919 Tix with _tkinter, since Tix will be loaded with Tcl's "package
920 require" command. See Demo/tix/.
921
922- tzparse.py is now obsolete.
923
924- In gzip.py, the seek() and tell() methods are removed -- they were
925 non-functional anyway, and it's better if callers can test for their
926 existence with hasattr().
927
928Python/C API
929
930- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
931 that's already in the dictionary during a PyDict_Next() iteration.
932 This used to fail occasionally when a dictionary resize operation
933 could be triggered that would rehash all the keys. All other
934 modifications to the dictionary are still off-limits during a
935 PyDict_Next() iteration!
936
937- New extended APIs related to passing compiler variables around.
938
939- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
940 implement isinstance() and issubclass().
941
942- Py_BuildValue() now has a "D" conversion to create a Python complex
943 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000944
Fred Drake4e262a92001-03-22 18:26:47 +0000945- Extensions types which support weak references must now set the
946 field allocated for the weak reference machinery to NULL themselves;
947 this is done to avoid the cost of checking each object for having a
948 weakly referencable type in PyObject_INIT(), since most types are
949 not weakly referencable.
950
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000951- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
952 free variables and cell variables to and from the frame's f_locals.
953
954- Variants of several functions defined in pythonrun.h have been added
955 to support the nested_scopes future statement. The variants all end
956 in Flags and take an extra argument, a PyCompilerFlags *; examples:
957 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
958 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000959 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000960
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000961Distutils
962
963- the sdist command now writes a PKG-INFO file, as described in PEP 241,
964 into the release tree.
965
Tim Peters0e57abf2001-05-02 07:39:38 +0000966- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000967 (an uninstaller, more customization of the installer's display)
968
969- from Jack Jansen: added Mac-specific code to generate a dialog for
970 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000971 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000972 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000973
974- added 'platforms' and 'keywords' to the set of metadata that can be
975 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000976
977- applied patches from Jason Tishler to make the compiler class work with
978 Cygwin.
979
980
Tim Peters2fe289a2001-03-01 22:19:38 +0000981What's New in Python 2.1 beta 1?
982================================
Tim Petersd66595f2001-02-04 03:09:53 +0000983
984Core language, builtins, and interpreter
985
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000986- Following an outcry from the community about the amount of code
987 broken by the nested scopes feature introduced in 2.1a2, we decided
988 to make this feature optional, and to wait until Python 2.2 (or at
989 least 6 months) to make it standard. The option can be enabled on a
990 per-module basis by adding "from __future__ import nested_scopes" at
991 the beginning of a module (before any other statements, but after
992 comments and an optional docstring). See PEP 236 (Back to the
993 __future__) for a description of the __future__ statement. PEP 227
994 (Statically Nested Scopes) has been updated to reflect this change,
995 and to clarify the semantics in a number of endcases.
996
997- The nested scopes code, when enabled, has been hardened, and most
998 bugs and memory leaks in it have been fixed.
999
1000- Compile-time warnings are now generated for a number of conditions
1001 that will break or change in meaning when nested scopes are enabled:
1002
1003 - Using "from...import *" or "exec" without in-clause in a function
1004 scope that also defines a lambda or nested function with one or
1005 more free (non-local) variables. The presence of the import* or
1006 bare exec makes it impossible for the compiler to determine the
1007 exact set of local variables in the outer scope, which makes it
1008 impossible to determine the bindings for free variables in the
1009 inner scope. To avoid the warning about import *, change it into
1010 an import of explicitly name object, or move the import* statement
1011 to the global scope; to avoid the warning about bare exec, use
1012 exec...in... (a good idea anyway -- there's a possibility that
1013 bare exec will be deprecated in the future).
1014
1015 - Use of a global variable in a nested scope with the same name as a
1016 local variable in a surrounding scope. This will change in
1017 meaning with nested scopes: the name in the inner scope will
1018 reference the variable in the outer scope rather than the global
1019 of the same name. To avoid the warning, either rename the outer
1020 variable, or use a global statement in the inner function.
1021
Neil Schemenauera35c6882001-02-27 04:45:05 +00001022- An optional object allocator has been included. This allocator is
1023 optimized for Python objects and should be faster and use less memory
1024 than the standard system allocator. It is not enabled by default
1025 because of possible thread safety problems. The allocator is only
1026 protected by the Python interpreter lock and it is possible that some
1027 extension modules require a thread safe allocator. The object
1028 allocator can be enabled by providing the "--with-pymalloc" option to
1029 configure.
1030
Tim Petersd66595f2001-02-04 03:09:53 +00001031Standard library
1032
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001033- pyexpat now detects the expat version if expat.h defines it. A
1034 number of additional handlers are provided, which are only available
1035 since expat 1.95. In addition, the methods SetParamEntityParsing and
1036 GetInputContext of Parser objects are available with 1.95.x
1037 only. Parser objects now provide the ordered_attributes and
1038 specified_attributes attributes. A new module expat.model was added,
1039 which offers a number of additional constants if 1.95.x is used.
1040
1041- xml.dom offers the new functions registerDOMImplementation and
1042 getDOMImplementation.
1043
1044- xml.dom.minidom offers a toprettyxml method. A number of DOM
1045 conformance issues have been resolved. In particular, Element now
1046 has an hasAttributes method, and the handling of namespaces was
1047 improved.
1048
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001049- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1050 getting information about live Python code, and pydoc.py, a module
1051 for interactively converting docstrings to HTML or text.
1052 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001053 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001054 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1055 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001056
Tim Peters1eff7962001-03-01 02:31:33 +00001057- New library module difflib.py, primarily packaging the SequenceMatcher
1058 class at the heart of the popular ndiff.py file-comparison tool.
1059
1060- doctest.py (a framework for verifying Python code examples in docstrings)
1061 is now part of the std library.
1062
Tim Petersd66595f2001-02-04 03:09:53 +00001063Windows changes
1064
Guido van Rossume3955a82001-03-02 14:05:59 +00001065- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1066 small GUI that lets you browse the module docstrings using your
1067 default web browser.
1068
Tim Peters1eff7962001-03-01 02:31:33 +00001069- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1070 Platforms) is implemented. See
1071
1072 http://python.sourceforge.net/peps/pep-0235.html
1073
1074 for full details, especially the "Current Lower-Left Semantics" section.
1075 The new Windows import rules are simpler than before:
1076
1077 A. If the PYTHONCASEOK environment variable exists, same as
1078 before: silently accept the first case-insensitive match of any
1079 kind; raise ImportError if none found.
1080
1081 B. Else search sys.path for the first case-sensitive match; raise
1082 ImportError if none found.
1083
1084 The same rules have been implented on other platforms with case-
1085 insensitive but case-preserving filesystems too (including Cygwin, and
1086 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001087
Tim Peters25a9ce32001-02-19 07:06:36 +00001088- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1089 what it's supposed to do (and does do under NT and 2000) via direct
1090 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001091 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001092 all Win9x systems before.
1093
Tim Peters1eff7962001-03-01 02:31:33 +00001094- Build: Subproject _test (effectively) renamed to _testcapi.
1095
Tim Peters2fe289a2001-03-01 22:19:38 +00001096New platforms
1097
1098- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1099 Thanks to Steven Majewski!
1100
1101- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1102 Tishler!
1103
Guido van Rossum9089b272001-03-02 06:49:50 +00001104- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1105 Schwertberger! See RISCOS/README for more information -- it seems
1106 that because of the bizarre filename conventions on RISCOS, no port
1107 to that platform is easy. Note that the new variable os.endsep is
1108 silently supported in order to make life easier on this platform,
1109 but we don't advertise it because it's not worth for most folks to
1110 care about RISCOS portability.
1111
Tim Peters25a9ce32001-02-19 07:06:36 +00001112
Tim Petersd7b5e882001-01-25 03:36:26 +00001113What's New in Python 2.1 alpha 2?
1114=================================
Tim Peters40ead762001-01-27 05:35:26 +00001115
Tim Petersd7b5e882001-01-25 03:36:26 +00001116Core language, builtins, and interpreter
1117
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001118- Scopes nest. If a name is used in a function or class, but is not
1119 local, the definition in the nearest enclosing function scope will
1120 be used. One consequence of this change is that lambda statements
1121 could reference variables in the namespaces where the lambda is
1122 defined. In some unusual cases, this change will break code.
1123
1124 In all previous version of Python, names were resolved in exactly
1125 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001126 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001127 function A is defined within a function B, the names bound in B are
1128 not visible in A. The new rules make names bound in B visible in A,
1129 unless A contains a name binding that hides the binding in B.
1130
1131 Section 4.1 of the reference manual describes the new scoping rules
1132 in detail. The test script in Lib/test/test_scope.py demonstrates
1133 some of the effects of the change.
1134
1135 The new rules will cause existing code to break if it defines nested
1136 functions where an outer function has local variables with the same
1137 name as globals or builtins used by the inner function. Example:
1138
1139 def munge(str):
1140 def helper(x):
1141 return str(x)
1142 if type(str) != type(''):
1143 str = helper(str)
1144 return str.strip()
1145
1146 Under the old rules, the name str in helper() is bound to the
1147 builtin function str(). Under the new rules, it will be bound to
1148 the argument named str and an error will occur when helper() is
1149 called.
1150
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001151- The compiler will report a SyntaxError if "from ... import *" occurs
1152 in a function or class scope. The language reference has documented
1153 that this case is illegal, but the compiler never checked for it.
1154 The recent introduction of nested scope makes the meaning of this
1155 form of name binding ambiguous. In a future release, the compiler
1156 may allow this form when there is no possibility of ambiguity.
1157
Tim Peters40ead762001-01-27 05:35:26 +00001158- repr(string) is easier to read, now using hex escapes instead of octal,
1159 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1160
1161 >>> "\texample \r\n" + chr(0) + chr(255)
1162 '\texample \r\n\x00\xff' # in 2.1
1163 '\011example \015\012\000\377' # in 2.0
1164
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001165- Functions are now compared and hashed by identity, not by value, since
1166 the func_code attribute is writable.
1167
Fred Drakefb9d7122001-02-01 20:00:40 +00001168- Weak references (PEP 205) have been added. This involves a few
1169 changes in the core, an extension module (_weakref), and a Python
1170 module (weakref). The weakref module is the public interface. It
1171 includes support for "explicit" weak references, proxy objects, and
1172 mappings with weakly held values.
1173
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001174- A 'continue' statement can now appear in a try block within the body
1175 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001176 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001177
Tim Petersd7b5e882001-01-25 03:36:26 +00001178Standard library
1179
Barry Warsaw30dbd142001-01-31 22:14:01 +00001180- mailbox.py now has a new class, PortableUnixMailbox which is
1181 identical to UnixMailbox but uses a more portable scheme for
1182 determining From_ separators. Also, the constructors for all the
1183 classes in this module have a new optional `factory' argument, which
1184 is a callable used when new message classes must be instantiated by
1185 the next() method.
1186
Tim Petersd7b5e882001-01-25 03:36:26 +00001187- random.py is now self-contained, and offers all the functionality of
1188 the now-deprecated whrandom.py. See the docs for details. random.py
1189 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001190 and restoring the internal state of the generator; and jumpahead(n),
1191 for quickly forcing the internal state to be the same as if n calls to
1192 random() had been made. The latter is particularly useful for multi-
1193 threaded programs, creating one instance of the random.Random() class for
1194 each thread, then using .jumpahead() to force each instance to use a
1195 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001196
Tim Peters0de88fc2001-02-01 04:59:18 +00001197- random.py's seed() function is new. For bit-for-bit compatibility with
1198 prior releases, use the whseed function instead. The new seed function
1199 addresses two problems: (1) The old function couldn't produce more than
1200 about 2**24 distinct internal states; the new one about 2**45 (the best
1201 that can be done in the Wichmann-Hill generator). (2) The old function
1202 sometimes produced identical internal states when passed distinct
1203 integers, and there was no simple way to predict when that would happen;
1204 the new one guarantees to produce distinct internal states for all
1205 arguments in [0, 27814431486576L).
1206
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001207- The socket module now supports raw packets on Linux. The socket
1208 family is AF_PACKET.
1209
Tim Peters9ea17ac2001-02-02 05:57:15 +00001210- test_capi.py is a start at running tests of the Python C API. The tests
1211 are implemented by the new Modules/_testmodule.c.
1212
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001213- A new extension module, _symtable, provides provisional access to the
1214 internal symbol table used by the Python compiler. A higher-level
1215 interface will be added on top of _symtable in a future release.
1216
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001217- Removed the obsolete soundex module.
1218
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001219- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1220 the isSameNode method; NamedNodeMap the get method.
1221
1222- xml.sax.expatreader supports the lexical handler property; it
1223 generates comment, startCDATA, and endCDATA events.
1224
Tim Petersee826f82001-01-31 19:39:44 +00001225Windows changes
1226
1227- Build procedure: the zlib project is built in a different way that
1228 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001229 the zlib binary used. See PCbuild\readme.txt for details. Your old
1230 zlib-related directories can be deleted; you'll need to download fresh
1231 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001232
Tim Peters9ea17ac2001-02-02 05:57:15 +00001233- Build: New subproject _test for the benefit of test_capi.py (see above).
1234
Tim Petersb16c56f2001-02-02 21:24:51 +00001235- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1236 interface to some Python compiler internals).
1237
1238- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001239 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001240
Tim Petersa3a3a032000-11-30 05:22:44 +00001241What's New in Python 2.1 alpha 1?
1242=================================
1243
1244Core language, builtins, and interpreter
1245
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001246- There is a new Unicode companion to the PyObject_Str() API
1247 called PyObject_Unicode(). It behaves in the same way as the
1248 former, but assures that the returned value is an Unicode object
1249 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001250
Guido van Rossumf98eda02001-01-17 15:54:45 +00001251- The comparison operators support "rich comparison overloading" (PEP
1252 207). C extension types can provide a rich comparison function in
1253 the new tp_richcompare slot in the type object. The cmp() function
1254 and the C function PyObject_Compare() first try the new rich
1255 comparison operators before trying the old 3-way comparison. There
1256 is also a new C API PyObject_RichCompare() (which also falls back on
1257 the old 3-way comparison, but does not constrain the outcome of the
1258 rich comparison to a Boolean result).
1259
1260 The rich comparison function takes two objects (at least one of
1261 which is guaranteed to have the type that provided the function) and
1262 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1263 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1264 object, which may be NotImplemented (in which case the tp_compare
1265 slot function is used as a fallback, if defined).
1266
1267 Classes can overload individual comparison operators by defining one
1268 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001269 __ge__. There are no explicit "reflected argument" versions of
1270 these; instead, __lt__ and __gt__ are each other's reflection,
1271 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1272 reflection (similar at the C level). No other implications are
1273 made; in particular, Python does not assume that == is the Boolean
1274 inverse of !=, or that < is the Boolean inverse of >=. This makes
1275 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001276
1277 Classes or types that want to implement (in)equality tests but not
1278 the ordering operators (i.e. unordered types) should implement ==
1279 and !=, and raise an error for the ordering operators.
1280
Guido van Rossuma88479f2001-01-18 14:28:08 +00001281 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001282 Boolean; e.g. a matrix type might want to return a matrix of bits
1283 for A < B, giving elementwise comparisons. Such types should ensure
1284 that any interpretation of their value in a Boolean context raises
1285 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1286 at the C level) to always raise an exception.
1287
Guido van Rossuma88479f2001-01-18 14:28:08 +00001288- Complex numbers use rich comparisons to define == and != but raise
1289 an exception for <, <=, > and >=. Unfortunately, this also means
1290 that cmp() of two complex numbers raises an exception when the two
1291 numbers differ. Since it is not mathematically meaningful to compare
1292 complex numbers except for equality, I hope that this doesn't break
1293 too much code.
1294
Tim Peters3389f192001-02-18 08:48:49 +00001295- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001296 not defined by the language, other than that it's arbitrary but
1297 consistent (see the Reference Manual). An implementation detail changed
1298 in 2.1a1 such that None now compares less than any other object. Code
1299 relying on this new behavior (like code that relied on the previous
1300 behavior) does so at its own risk.
1301
Barry Warsaw573b5412001-01-15 20:43:18 +00001302- Functions and methods now support getting and setting arbitrarily
1303 named attributes (PEP 232). Functions have a new __dict__
1304 (a.k.a. func_dict) which hold the function attributes. Methods get
1305 and set attributes on their underlying im_func. It is a TypeError
1306 to set an attribute on a bound method.
1307
Guido van Rossum051e3352001-01-15 19:11:10 +00001308- The xrange() object implementation has been improved so that
1309 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1310 limitation that in this case len(xrange(sys.maxint)) can't be
1311 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1312 work fine as long as the index i doesn't actually reach 2**31.
1313 (Python uses regular ints for sequence and string indices; fixing
1314 that is much more work.)
1315
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001316- Two changes to from...import:
1317
Guido van Rossumba381232001-02-03 15:06:40 +00001318 1) "from M import X" now works even if (after loading module M)
1319 sys.modules['M'] is not a real module; it's basically a getattr()
1320 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001321
1322 2) "from M import *" now looks for M.__all__ to decide which names to
1323 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1324 filters out names starting with '_' as before. Whether or not
1325 __all__ exists, there's no restriction on the type of M.
1326
Guido van Rossumf61f1662001-01-10 20:13:55 +00001327- File objects have a new method, xreadlines(). This is the fastest
1328 way to iterate over all lines in a file:
1329
1330 for line in file.xreadlines():
1331 ...do something to line...
1332
1333 See the xreadlines module (mentioned below) for how to do this for
1334 other file-like objects.
1335
1336- Even if you don't use file.xreadlines(), you may expect a speedup on
1337 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001338 quite a bit in platform-specific ways: on systems (like Linux) that
1339 support flockfile(), getc_unlocked(), and funlockfile(), those are
1340 used by default. On systems (like Windows) without getc_unlocked(),
1341 a complicated (but still thread-safe) method using fgets() is used by
1342 default.
1343
Tim Petersd52269b2001-01-25 06:23:18 +00001344 You can force use of the fgets() method by #define'ing
1345 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001346 getc_unlocked()).
1347
Tim Petersd52269b2001-01-25 06:23:18 +00001348 You can force fgets() not to be used by #define'ing
1349 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001350 test_bufio.py fails -- and let us know if it does!).
1351
1352- In addition, the fileinput module, while still slower than the other
1353 methods on most platforms, has been sped up too, by using
1354 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001355
1356- Support for run-time warnings has been added, including a new
1357 command line option (-W) to specify the disposition of warnings.
1358 See the description of the warnings module below.
1359
1360- Extensive changes have been made to the coercion code. This mostly
1361 affects extension modules (which can now implement mixed-type
1362 numerical operators without having to use coercion), but
1363 occasionally, in boundary cases the coercion semantics have changed
1364 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001365 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001366 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001367 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001368
Guido van Rossumf98eda02001-01-17 15:54:45 +00001369- In connection with the coercion changes, a new built-in singleton
1370 object, NotImplemented is defined. This can be returned for
1371 operations that wish to indicate they are not implemented for a
1372 particular combination of arguments. From C, this is
1373 Py_NotImplemented.
1374
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001375- The interpreter accepts now bytecode files on the command line even
1376 if they do not have a .pyc or .pyo extension. On Linux, after executing
1377
Martin v. Löwise214baa2001-02-04 22:37:56 +00001378import imp,sys,string
1379magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1380reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1381open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001382
1383 any byte code file can be used as an executable (i.e. as an argument
1384 to execve(2)).
1385
Tim Peters9940b802000-12-01 07:59:35 +00001386- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001387 character. In 1.6 and earlier, they never produced a sign,
1388 and raised an error if the value of the long was too large
1389 to fit in a Python int. In 2.0, they produced a sign if and
1390 only if too large to fit in an int. This was inconsistent
1391 across platforms (because the size of an int varies across
1392 platforms), and inconsistent with hex() and oct(). Example:
1393
1394 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001395 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001396 'ffffffbe' # in 2.0 and before, on 32-bit machines
1397 >>> hex(-0x42L)
1398 '-0x42L' # in all versions of Python
1399
Tim Peters9940b802000-12-01 07:59:35 +00001400 The behavior of %d formats for negative Python longs remains
1401 the same as in 2.0 (although in 1.6 and before, they raised
1402 an error if the long didn't fit in a Python int).
1403
1404 %u formats don't make sense for Python longs, but are allowed
1405 and treated the same as %d in 2.1. In 2.0, a negative long
1406 formatted via %u produced a sign if and only if too large to
1407 fit in an int. In 1.6 and earlier, a negative long formatted
1408 via %u raised an error if it was too big to fit in an int.
1409
Guido van Rossum3661d392000-12-12 22:10:31 +00001410- Dictionary objects have an odd new method, popitem(). This removes
1411 an arbitrary item from the dictionary and returns it (in the form of
1412 a (key, value) pair). This can be useful for algorithms that use a
1413 dictionary as a bag of "to do" items and repeatedly need to pick one
1414 item. Such algorithms normally end up running in quadratic time;
1415 using popitem() they can usually be made to run in linear time.
1416
Tim Peters36cdad12000-12-29 02:06:45 +00001417Standard library
1418
Thomas Woutersfe385252001-01-19 23:16:56 +00001419- In the time module, the time argument to the functions strftime,
1420 localtime, gmtime, asctime and ctime is now optional, defaulting to
1421 the current time (in the local timezone).
1422
Guido van Rossumda91f222001-01-15 16:36:08 +00001423- The ftplib module now defaults to passive mode, which is deemed a
1424 more useful default given that clients are often inside firewalls
1425 these days. Note that this could break if ftplib is used to connect
1426 to a *server* that is inside a firewall, from outside; this is
1427 expected to be a very rare situation. To fix that, you can call
1428 ftp.set_pasv(0).
1429
Martin v. Löwis10a27872001-01-13 09:54:41 +00001430- The module site now treats .pth files not only for path configuration,
1431 but also supports extensions to the initialization code: Lines starting
1432 with import are executed.
1433
Guido van Rossumf61f1662001-01-10 20:13:55 +00001434- There's a new module, warnings, which implements a mechanism for
1435 issuing and filtering warnings. There are some new built-in
1436 exceptions that serve as warning categories, and a new command line
1437 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1438 turns warnings into errors). warnings.warn(message[, category])
1439 issues a warning message; this can also be called from C as
1440 PyErr_Warn(category, message).
1441
1442- A new module xreadlines was added. This exports a single factory
1443 function, xreadlines(). The intention is that this code is the
1444 absolutely fastest way to iterate over all lines in an open
1445 file(-like) object:
1446
1447 import xreadlines
1448 for line in xreadlines.xreadlines(file):
1449 ...do something to line...
1450
1451 This is equivalent to the previous the speed record holder using
1452 file.readlines(sizehint). Note that if file is a real file object
1453 (as opposed to a file-like object), this is equivalent:
1454
1455 for line in file.xreadlines():
1456 ...do something to line...
1457
Tim Peters36cdad12000-12-29 02:06:45 +00001458- The bisect module has new functions bisect_left, insort_left,
1459 bisect_right and insort_right. The old names bisect and insort
1460 are now aliases for bisect_right and insort_right. XXX_right
1461 and XXX_left methods differ in what happens when the new element
1462 compares equal to one or more elements already in the list: the
1463 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001464 right. Code that doesn't care where equal elements end up should
1465 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001466
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001467- The new curses.panel module wraps the panel library that forms part
1468 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1469
Guido van Rossumf61f1662001-01-10 20:13:55 +00001470- The SocketServer module now sets the allow_reuse_address flag by
1471 default in the TCPServer class.
1472
1473- A new function, sys._getframe(), returns the stack frame pointer of
1474 the caller. This is intended only as a building block for
1475 higher-level mechanisms such as string interpolation.
1476
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001477- The pyexpat module supports a number of new handlers, which are
1478 available only in expat 1.2. If invocation of a callback fails, it
1479 will report an additional frame in the traceback. Parser objects
1480 participate now in garbage collection. If expat reports an unknown
1481 encoding, pyexpat will try to use a Python codec; that works only
1482 for single-byte charsets. The parser type objects is exposed as
1483 XMLParserObject.
1484
1485- xml.dom now offers standard definitions for symbolic node type and
1486 exception code constants, and a hierarchy of DOM exceptions. minidom
1487 was adjusted to use them.
1488
1489- The conformance of xml.dom.minidom to the DOM specification was
1490 improved. It detects a number of additional error cases; the
1491 previous/next relationship works even when the tree is modified;
1492 Node supports the normalize() method; NamedNodeMap, DocumentType and
1493 DOMImplementation classes were added; Element supports the
1494 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1495 method.
1496
Guido van Rossumf61f1662001-01-10 20:13:55 +00001497Build issues
1498
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001499- For Unix (and Unix-compatible) builds, configuration and building of
1500 extension modules is now greatly automated. Rather than having to
1501 edit the Modules/Setup file to indicate which modules should be
1502 built and where their include files and libraries are, a
1503 distutils-based setup.py script now takes care of building most
1504 extension modules. All extension modules built this way are built
1505 as shared libraries. Only a few modules that must be linked
1506 statically are still listed in the Setup file; you won't need to
1507 edit their configuration.
1508
1509- Python should now build out of the box on Cygwin. If it doesn't,
1510 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001511
1512- Python now always uses its own (renamed) implementation of getopt()
1513 -- there's too much variation among C library getopt()
1514 implementations.
1515
1516- C++ compilers are better supported; the CXX macro is always set to a
1517 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001518
Tim Petersd92dfe02000-12-12 01:18:41 +00001519Windows changes
1520
1521- select module: By default under Windows, a select() call
1522 can specify no more than 64 sockets. Python now boosts
1523 this Microsoft default to 512. If you need even more than
1524 that, see the MS docs (you'll need to #define FD_SETSIZE
1525 and recompile Python from source).
1526
Guido van Rossumf61f1662001-01-10 20:13:55 +00001527- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1528 subdirectory is no more!
1529
Tim Petersa3a3a032000-11-30 05:22:44 +00001530
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001531What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001532=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001533
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001534Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001535changes are in the file HISTORY. If you are making the jump directly
1536from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1537HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001538
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001539Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1540the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1541http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001542
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001543--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001544
1545======================================================================
1546
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001547What's new in 2.0 (since release candidate 1)?
1548==============================================
1549
1550Standard library
1551
1552- The copy_reg module was modified to clarify its intended use: to
1553 register pickle support for extension types, not for classes.
1554 pickle() will raise a TypeError if it is passed a class.
1555
1556- Fixed a bug in gettext's "normalize and expand" code that prevented
1557 it from finding an existing .mo file.
1558
1559- Restored support for HTTP/0.9 servers in httplib.
1560
Tim Peters989b7b92000-10-16 20:24:53 +00001561- The math module was changed to stop raising OverflowError in case of
1562 underflow, and return 0 instead in underflow cases. Whether Python
1563 used to raise OverflowError in case of underflow was platform-
1564 dependent (it did when the platform math library set errno to ERANGE
1565 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001566
1567- Fixed a bug in StringIO that occurred when the file position was not
1568 at the end of the file and write() was called with enough data to
1569 extend past the end of the file.
1570
1571- Fixed a bug that caused Tkinter error messages to get lost on
1572 Windows. The bug was fixed by replacing direct use of
1573 interp->result with Tcl_GetStringResult(interp).
1574
1575- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1576 redirect response.
1577
1578- Several changes were made to distutils: Some debugging code was
1579 removed from util. Fixed the installer used when an external zip
1580 program (like WinZip) is not found; the source code for this
1581 installer is in Misc/distutils. check_lib() was modified to behave
1582 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1583 test for whether installed modules are on sys.path was changed to
1584 use both normcase() and normpath().
1585
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001586- Several minor bugs were fixed in the xml package (the minidom,
1587 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001588
1589- The regression test driver (regrtest.py) behavior when invoked with
1590 -l changed: It now reports a count of objects that are recognized as
1591 garbage but not freed by the garbage collector.
1592
Tim Peters989b7b92000-10-16 20:24:53 +00001593- The regression test for the math module was changed to test
1594 exceptional behavior when the test is run in verbose mode. Python
1595 cannot yet guarantee consistent exception behavior across platforms,
1596 so the exception part of test_math is run only in verbose mode, and
1597 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001598
1599Internals
1600
1601- PyOS_CheckStack() has been disabled on Win64, where it caused
1602 test_sre to fail.
1603
1604Build issues
1605
1606- Changed compiler flags, so that gcc is always invoked with -Wall and
1607 -Wstrict-prototypes. Users compiling Python with GCC should see
1608 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001609 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001610 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001611
Tim Petersa3a3a032000-11-30 05:22:44 +00001612- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001613
1614Tools and other miscellany
1615
1616- The compiler in Tools/compiler was updated to support the new
1617 language features introduced in 2.0: extended print statement, list
1618 comprehensions, and augmented assignments. The new compiler should
1619 also be backwards compatible with Python 1.5.2; the compiler will
1620 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001621 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001622
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001623What's new in 2.0 release candidate 1 (since beta 2)?
1624=====================================================
1625
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001626What is release candidate 1?
1627
1628We believe that release candidate 1 will fix all known bugs that we
1629intend to fix for the 2.0 final release. This release should be a bit
1630more stable than the previous betas. We would like to see even more
1631widespread testing before the final release, so we are producing this
1632release candidate. The final release will be exactly the same unless
1633any show-stopping (or brown bag) bugs are found by testers of the
1634release candidate.
1635
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001636All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001637to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001638
1639Core language, builtins, and interpreter
1640
1641- A bug that caused crashes when __coerce__ was used with augmented
1642 assignment, e.g. +=, was fixed.
1643
1644- Raise ZeroDivisionError when raising zero to a negative number,
1645 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1646 power operator and the result of math.pow(0.0, -2.0) will vary by
1647 platform. On Linux, it raises a ValueError.
1648
1649- A bug in Unicode string interpolation was fixed that occasionally
1650 caused errors with formats including "%%". For example, the
1651 following expression "%% %s" % u"abc" no longer raises a TypeError.
1652
1653- Compilation of deeply nested expressions raises MemoryError instead
1654 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1655
1656- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1657 rendering them useless. They are now written in binary mode again.
1658
1659Standard library
1660
1661- Keyword arguments are now accepted for most pattern and match object
1662 methods in SRE, the standard regular expression engine.
1663
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001664- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001665 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001666
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001667- Several bugs in the Unicode handling and error handling in _tkinter
1668 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001669
1670- Fix memory management errors in Merge() and Tkapp_Call() routines.
1671
1672- Several changes were made to cStringIO to make it compatible with
1673 the file-like object interface and with StringIO. If operations are
1674 performed on a closed object, an exception is raised. The truncate
1675 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001676 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001677
1678- There were many changes made to the linuxaudiodev module and its
1679 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001680 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001681
1682 Note that this module is named poorly, because it should work
1683 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001684 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001685
1686 The module now raises exceptions when errors occur instead of
1687 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1688 audio) and defines a getptr() method that calls the
1689 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1690
1691- The library_version attribute, introduced in an earlier beta, was
1692 removed because it can not be supported with early versions of the C
1693 readline library, which provides no way to determine the version at
1694 compile-time.
1695
1696- The binascii module is now enabled on Win64.
1697
Tim Peters46446d62000-10-09 21:19:31 +00001698- tokenize.py no longer suffers "recursion depth" errors when parsing
1699 programs with very long string literals.
1700
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001701Internals
1702
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001703- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001704 which is called when the interpreter starts up to determine where
1705 the standard library is installed. These vulnerabilities affect all
1706 previous versions of Python and can be exploited by setting very
1707 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1708 setuid Python script, although use of the wrapper in
1709 Misc/setuid-prog.c will eliminate the vulnerability.
1710
1711- Fixed garbage collection bugs in instance creation that were
1712 triggered when errors occurred during initialization. The solution,
1713 applied in cPickle and in PyInstance_New(), is to call
1714 PyObject_GC_Init() after the initialization of the object's
1715 container attributes is complete.
1716
1717- pyexpat adds definitions of PyModule_AddStringConstant and
1718 PyModule_AddObject if the Python version is less than 2.0, which
1719 provides compatibility with PyXML on Python 1.5.2.
1720
1721- If the platform has a bogus definition for LONG_BIT (the number of
1722 bits in a long), an error will be reported at compile time.
1723
1724- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1725 collection crashes and possibly other, unreported crashes.
1726
1727- Fixed a memory leak in _PyUnicode_Fini().
1728
1729Build issues
1730
1731- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001732 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001733 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001734
1735- The mmap.PAGESIZE constant is now initialized using sysconf when
1736 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1737
1738- The md5 file should now compile on all platforms.
1739
1740- The select module now compiles on platforms that do not define
1741 POLLRDNORM and related constants.
1742
1743- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001744 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001745
Jeremy Hylton10921202000-10-09 18:34:12 +00001746- BeOS: A number of changes were made to the build and installation
1747 process. ar-fake now operates on a directory of object files.
1748 dl_export.h is gone, and its macros now appear on the mwcc command
1749 line during build on PPC BeOS.
1750
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001751- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001752 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001753
1754- Cygwin: Support for shared libraries, Tkinter, and sockets.
1755
1756- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1757
1758Tools and other miscellany
1759
1760- Removed debugging prints from main used with freeze.
1761
Tim Peters46446d62000-10-09 21:19:31 +00001762- IDLE auto-indent no longer crashes when it encounters Unicode
1763 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001764
1765What's new in 2.0 beta 2 (since beta 1)?
1766========================================
1767
1768Core language, builtins, and interpreter
1769
Tim Peters482c0212000-09-26 06:33:09 +00001770- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001771 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001772
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001773- Add -h and -V command line options to print the usage message and
1774 Python version number and exit immediately.
1775
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001776- eval() and exec accept Unicode objects as code parameters.
1777
1778- getattr() and setattr() now also accept Unicode objects for the
1779 attribute name, which are converted to strings using the default
1780 encoding before lookup.
1781
1782- Multiplication on string and Unicode now does proper bounds
1783 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1784 string is too long."
1785
1786- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001787 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001788
Jeremy Hylton1b618592000-09-26 05:32:36 +00001789
1790Standard library and extensions
1791
Guido van Rossum5b08f132001-04-16 02:05:23 +00001792- socket module: the OpenSSL code now adds support for RAND_status()
1793 and EGD (Entropy Gathering Device).
1794
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001795- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001796 argument checking; it still takes no arguments.
1797
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001798- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001799
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001800- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001801
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001802- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001803
1804- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001805 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001806
1807- copy: Copy Unicode objects atomically.
1808
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001809- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001810
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001811- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001812
Fred Drake67233bc2000-09-26 16:40:27 +00001813- dbm: Add get() and setdefault() methods to dbm object. Add constant
1814 `library' to module that names the library used. Added doc strings
1815 and method names to error messages. Uses configure to determine
1816 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1817 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001818
1819- distutils: Update to version 0.9.3.
1820
1821- dl: Add several dl.RTLD_ constants.
1822
1823- fpectl: Now supported on FreeBSD.
1824
1825- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1826 found by the collector will be saved in gc.garbage. This is useful
1827 for debugging a program that creates reference cycles.
1828
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001829- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001830 of HTTP class. Do not close socket on zero-length response. Do not
1831 crash when server sends invalid content-length header.
1832
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001833- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001834
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001835- marshal: When reading a short, sign-extend on platforms where shorts
1836 are bigger than 16 bits. When reading a long, repair the unportable
1837 sign extension that was being done for 64-bit machines. (It assumed
1838 that signed right shift sign-extends.)
1839
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001840- operator: Add contains(), invert(), __invert__() as aliases for
1841 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001842
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001843- os: Add support for popen2() and popen3() on all platforms where
1844 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001845
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001846- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001847 clicking on a file in Explorer (or passing the file name to the
1848 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001849
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001850- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001851 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001852
1853- pickle: Now raises ValueError when an invalid pickle that contains
1854 a non-string repr where a string repr was expected. This behavior
1855 matches cPickle.
1856
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001857- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001858
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001859- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001860
1861- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001862 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001863 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001864
1865- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001866 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001867
1868- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001869 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001870 few cycles during startup since the first call to
1871 setdefaultencoding() will initialize the codec registry and the
1872 encodings package.
1873
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001874- socket: Support for size hint in readlines() method of object returned
1875 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001876
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001877- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001878 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001879 is followed by whitespace.
1880
Tim Petersa3a3a032000-11-30 05:22:44 +00001881- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001882
1883- struct: Check ranges for bytes and shorts.
1884
1885- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001886 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001887
1888- Tkinter: Image objects are now guaranteed to have unique ids. Set
1889 event.delta to zero if Tk version doesn't support mousewheel.
1890 Removed some debugging prints.
1891
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001892- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001893
Fred Drake67233bc2000-09-26 16:40:27 +00001894- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001895 which works around a bug in Norton AntiVirus 2000 that leads directly
1896 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001897
1898- xml: New version detection code allows PyXML to override standard
1899 XML package if PyXML version is greater than 0.6.1.
1900
Fred Drake64bb3802000-09-26 16:21:35 +00001901- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1902 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1903 tree only for nodes which are sufficiently interesting to a specific
1904 application. Does not provide the HTML-specific extensions. Still
1905 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001906
Fred Drake64bb3802000-09-26 16:21:35 +00001907- xml.sax: SAX 2 support for Python, including all the handler
1908 interfaces needed to process XML 1.0 compliant XML. Some
1909 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001910
Fred Drake64bb3802000-09-26 16:21:35 +00001911- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1912 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001913
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001914
Jeremy Hylton1b618592000-09-26 05:32:36 +00001915C API
1916
1917- Add three new convenience functions for module initialization --
1918 PyModule_AddObject(), PyModule_AddIntConstant(), and
1919 PyModule_AddStringConstant().
1920
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001921- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001922 removed and add #error to Python.h if NULL isn't defined after
1923 #include of stdio.h.
1924
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001925- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001926 backwards compatibility (at the source level) with old extensions.
1927
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001928- A wrapper API was added for signal() and sigaction(). Instead of
1929 either function, always use PyOS_getsig() to get a signal handler
1930 and PyOS_setsig() to set one. A new convenience typedef
1931 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001932
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001933- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001934 internal data buffer and size of a string object -- or the default
1935 encoded version of a Unicode object.
1936
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001937- PyString_Size() and PyString_AsString() accept Unicode objects.
1938
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001939- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001940 exists). INT_MAX and LONG_MAX will always be defined, even if
1941 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001942
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001943- PyFloat_FromString takes a second argument, pend, that was
1944 effectively useless. It is now officially useless but preserved for
1945 backwards compatibility. If the pend argument is not NULL, *pend is
1946 set to NULL.
1947
1948- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1949 for the attribute name. See note on getattr() above.
1950
1951- A few bug fixes to argument processing for Unicode.
1952 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1953 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1954 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001955 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001956
1957- Py_BuildValue accepts B format (for bgen-generated code).
1958
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001959
Jeremy Hylton1b618592000-09-26 05:32:36 +00001960Internals
1961
1962- On Unix, fix code for finding Python installation directory so that
1963 it works when argv[0] is a relative path.
1964
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001965- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001966 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001967 rather than by generating a copy of the object.
1968
Tim Peters482c0212000-09-26 06:33:09 +00001969- Several of the internal Unicode tables are much smaller now, and
1970 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001971
Jeremy Hylton97693b02000-09-26 17:42:51 +00001972- In the garbage collector: Fixed bug in collection of tuples. Fixed
1973 bug that caused some instances to be removed from the container set
1974 while they were still live. Fixed parsing in gc.set_debug() for
1975 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001976
1977- Fixed refcount problem in instance deallocation that only occurred
1978 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1979
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001980- On Windows, getpythonregpath is now protected against null data in
1981 registry key.
1982
1983- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001984 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001985
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001986
Jeremy Hylton1b618592000-09-26 05:32:36 +00001987Build and platform-specific issues
1988
1989- Better support of GNU Pth via --with-pth configure option.
1990
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001991- Python/C API now properly exposed to dynamically-loaded extension
1992 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001993
1994- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1995 Don't define MS_SYNC to be zero when it is undefined. Added missing
1996 prototypes in posixmodule.c.
1997
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001998- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001999 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002000
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002001- Fix largefile support on older NetBSD systems and OpenBSD by adding
2002 define for TELL64.
2003
2004
2005Tools and other miscellany
2006
2007- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2008
2009- freeze: The modulefinder now works with 2.0 opcodes.
2010
Tim Petersa3a3a032000-11-30 05:22:44 +00002011- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002012 Move hackery of sys.argv until after the Tk instance has been
2013 created, which allows the application-specific Tkinter
2014 initialization to be executed if present; also pass an explicit
2015 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002016
Jeremy Hylton1b618592000-09-26 05:32:36 +00002017
2018What's new in 2.0 beta 1?
2019=========================
2020
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002021Source Incompatibilities
2022------------------------
2023
2024None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2025such as single-argument append(), connect() and bind(), and changes to
2026str(long) and repr(float).
2027
2028
2029Binary Incompatibilities
2030------------------------
2031
2032- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2033with Python 2.0; these extensions will have to be rebuilt for Python
20342.0.
2035
2036- On Windows, attempting to import a third party extension built for
2037Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2038can do about this. Check your PYTHONPATH environment variable!
2039
2040- Python bytecode files (*.pyc and *.pyo) are not compatible between
2041releases.
2042
2043
2044Overview of Changes Since 1.6
2045-----------------------------
2046
2047There are many new modules (including brand new XML support through
2048the xml package, and i18n support through the gettext module); a list
2049of all new modules is included below. Lots of bugs have been fixed.
2050
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002051The process for making major new changes to the language has changed
2052since Python 1.6. Enhancements must now be documented by a Python
2053Enhancement Proposal (PEP) before they can be accepted.
2054
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002055There are several important syntax enhancements, described in more
2056detail below:
2057
2058 - Augmented assignment, e.g. x += 1
2059
2060 - List comprehensions, e.g. [x**2 for x in range(10)]
2061
2062 - Extended import statement, e.g. import Module as Name
2063
2064 - Extended print statement, e.g. print >> file, "Hello"
2065
2066Other important changes:
2067
2068 - Optional collection of cyclical garbage
2069
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002070Python Enhancement Proposal (PEP)
2071---------------------------------
2072
2073PEP stands for Python Enhancement Proposal. A PEP is a design
2074document providing information to the Python community, or describing
2075a new feature for Python. The PEP should provide a concise technical
2076specification of the feature and a rationale for the feature.
2077
2078We intend PEPs to be the primary mechanisms for proposing new
2079features, for collecting community input on an issue, and for
2080documenting the design decisions that have gone into Python. The PEP
2081author is responsible for building consensus within the community and
2082documenting dissenting opinions.
2083
2084The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002085
2086Augmented Assignment
2087--------------------
2088
2089This must have been the most-requested feature of the past years!
2090Eleven new assignment operators were added:
2091
Guido van Rossume905e952000-09-05 12:42:46 +00002092 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002093
2094For example,
2095
2096 A += B
2097
2098is similar to
2099
2100 A = A + B
2101
2102except that A is evaluated only once (relevant when A is something
2103like dict[index].attr).
2104
2105However, if A is a mutable object, A may be modified in place. Thus,
2106if A is a number or a string, A += B has the same effect as A = A+B
2107(except A is only evaluated once); but if a is a list, A += B has the
2108same effect as A.extend(B)!
2109
2110Classes and built-in object types can override the new operators in
2111order to implement the in-place behavior; the not-in-place behavior is
2112used automatically as a fallback when an object doesn't implement the
2113in-place behavior. For classes, the method name is derived from the
2114method name for the corresponding not-in-place operator by inserting
2115an 'i' in front of the name, e.g. __iadd__ implements in-place
2116__add__.
2117
2118Augmented assignment was implemented by Thomas Wouters.
2119
2120
2121List Comprehensions
2122-------------------
2123
2124This is a flexible new notation for lists whose elements are computed
2125from another list (or lists). The simplest form is:
2126
2127 [<expression> for <variable> in <sequence>]
2128
Guido van Rossum56db0952000-09-06 23:34:25 +00002129For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002130This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002131
2132You can also add a condition:
2133
2134 [<expression> for <variable> in <sequence> if <condition>]
2135
2136For example, [w for w in words if w == w.lower()] would yield the list
2137of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002138than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002139
2140You can also have nested for loops and more than one 'if' clause. For
2141example, here's a function that flattens a sequence of sequences::
2142
2143 def flatten(seq):
2144 return [x for subseq in seq for x in subseq]
2145
2146 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2147
2148This prints
2149
2150 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2151
2152List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002153Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002154
2155
2156Extended Import Statement
2157-------------------------
2158
2159Many people have asked for a way to import a module under a different
2160name. This can be accomplished like this:
2161
2162 import foo
2163 bar = foo
2164 del foo
2165
2166but this common idiom gets old quickly. A simple extension of the
2167import statement now allows this to be written as follows:
2168
2169 import foo as bar
2170
2171There's also a variant for 'from ... import':
2172
2173 from foo import bar as spam
2174
2175This also works with packages; e.g. you can write this:
2176
2177 import test.regrtest as regrtest
2178
2179Note that 'as' is not a new keyword -- it is recognized only in this
2180context (this is only possible because the syntax for the import
2181statement doesn't involve expressions).
2182
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002183Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002184
2185
2186Extended Print Statement
2187------------------------
2188
2189Easily the most controversial new feature, this extension to the print
2190statement adds an option to make the output go to a different file
2191than the default sys.stdout.
2192
2193For example, to write an error message to sys.stderr, you can now
2194write:
2195
2196 print >> sys.stderr, "Error: bad dog!"
2197
2198As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002199evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002200
2201 print >> None, "Hello world"
2202
2203is equivalent to
2204
2205 print "Hello world"
2206
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002207Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002208
2209
2210Optional Collection of Cyclical Garbage
2211---------------------------------------
2212
2213Python is now equipped with a garbage collector that can hunt down
2214cyclical references between Python objects. It's no replacement for
2215reference counting; in fact, it depends on the reference counts being
2216correct, and decides that a set of objects belong to a cycle if all
2217their reference counts can be accounted for from their references to
2218each other. This devious scheme was first proposed by Eric Tiedemann,
2219and brought to implementation by Neil Schemenauer.
2220
2221There's a module "gc" that lets you control some parameters of the
2222garbage collection. There's also an option to the configure script
2223that lets you enable or disable the garbage collection. In 2.0b1,
2224it's on by default, so that we (hopefully) can collect decent user
2225experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002226performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002227off by default in the final 2.0 release.
2228
2229
2230Smaller Changes
2231---------------
2232
2233A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2234map(None, seq1, seq2, ...) when the sequences have the same length;
2235i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2236the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002237zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002238
2239sys.version_info is a tuple (major, minor, micro, level, serial).
2240
2241Dictionaries have an odd new method, setdefault(key, default).
2242dict.setdefault(key, default) returns dict[key] if it exists; if not,
2243it sets dict[key] to default and returns that value. Thus:
2244
2245 dict.setdefault(key, []).append(item)
2246
2247does the same work as this common idiom:
2248
2249 if not dict.has_key(key):
2250 dict[key] = []
2251 dict[key].append(item)
2252
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002253There are two new variants of SyntaxError that are raised for
2254indentation-related errors: IndentationError and TabError.
2255
2256Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2257escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002258
2259The limits on the size of expressions and file in Python source code
2260have been raised from 2**16 to 2**32. Previous versions of Python
2261were limited because the maximum argument size the Python VM accepted
2262was 2**16. This limited the size of object constructor expressions,
2263e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2264limit was raised thanks to a patch by Charles Waldman that effectively
2265fixes the problem. It is now much more likely that you will be
2266limited by available memory than by an arbitrary limit in Python.
2267
2268The interpreter's maximum recursion depth can be modified by Python
2269programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2270limit is the maximum number of recursive calls that can be made by
2271Python code. The limit exists to prevent infinite recursion from
2272overflowing the C stack and causing a core dump. The default value is
22731000. The maximum safe value for a particular platform can be found
2274by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002275
2276New Modules and Packages
2277------------------------
2278
2279atexit - for registering functions to be called when Python exits.
2280
2281imputil - Greg Stein's alternative API for writing custom import
2282hooks.
2283
2284pyexpat - an interface to the Expat XML parser, contributed by Paul
2285Prescod.
2286
2287xml - a new package with XML support code organized (so far) in three
2288subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2289would fill a volume. There's a special feature whereby a
2290user-installed package named _xmlplus overrides the standard
2291xmlpackage; this is intended to give the XML SIG a hook to distribute
2292backwards-compatible updates to the standard xml package.
2293
2294webbrowser - a platform-independent API to launch a web browser.
2295
2296
Guido van Rossume905e952000-09-05 12:42:46 +00002297Changed Modules
2298---------------
2299
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002300array -- new methods for array objects: count, extend, index, pop, and
2301remove
2302
2303binascii -- new functions b2a_hex and a2b_hex that convert between
2304binary data and its hex representation
2305
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002306calendar -- Many new functions that support features including control
2307over which day of the week is the first day, returning strings instead
2308of printing them. Also new symbolic constants for days of week,
2309e.g. MONDAY, ..., SUNDAY.
2310
2311cgi -- FieldStorage objects have a getvalue method that works like a
2312dictionary's get method and returns the value attribute of the object.
2313
2314ConfigParser -- The parser object has new methods has_option,
2315remove_section, remove_option, set, and write. They allow the module
2316to be used for writing config files as well as reading them.
2317
2318ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002319optionally support the RFC 959 REST command.
2320
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002321gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002322
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002323httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2324the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002325
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002326locale -- implement getdefaultlocale for Win32 and Macintosh
2327
2328marshal -- no longer dumps core when marshaling deeply nested or
2329recursive data structures
2330
2331os -- new functions isatty, seteuid, setegid, setreuid, setregid
2332
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002333os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2334support under Unix.
2335
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002336os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002337
2338os.path -- fix semantics of os.path.commonprefix
2339
2340smtplib -- support for sending very long messages
2341
2342socket -- new function getfqdn()
2343
2344readline -- new functions to read, write and truncate history files.
2345The readline section of the library reference manual contains an
2346example.
2347
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002348select -- add interface to poll system call
2349
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002350shutil -- new copyfileobj function
2351
2352SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2353HTTP server.
2354
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002355Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002356
2357urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002358e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002359
2360whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002361
2362
2363Obsolete Modules
2364----------------
2365
2366None. However note that 1.6 made a whole slew of modules obsolete:
2367stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2368poly, zmod, strop, util, whatsound.
2369
2370
2371Changed, New, Obsolete Tools
2372----------------------------
2373
Tim Peters8b092332000-09-05 20:15:25 +00002374None.
Guido van Rossume905e952000-09-05 12:42:46 +00002375
2376
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002377C-level Changes
2378---------------
2379
2380Several cleanup jobs were carried out throughout the source code.
2381
2382All C code was converted to ANSI C; we got rid of all uses of the
2383Py_PROTO() macro, which makes the header files a lot more readable.
2384
2385Most of the portability hacks were moved to a new header file,
2386pyport.h; several other new header files were added and some old
2387header files were removed, in an attempt to create a more rational set
2388of header files. (Few of these ever need to be included explicitly;
2389they are all included by Python.h.)
2390
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002391Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002392and Win64, especially for the new Intel Itanium processor. Mick also
2393added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002394
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002395The C APIs to return an object's size have been update to consistently
2396use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2397previous versions, the abstract interfaces used PyXXX_Length and the
2398concrete interfaces used PyXXX_Size. The old names,
2399e.g. PyObject_Length, are still available for backwards compatibility
2400at the API level, but are deprecated.
2401
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002402The PyOS_CheckStack function has been implemented on Windows by
2403Fredrik Lundh. It prevents Python from failing with a stack overflow
2404on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002405
2406The GC changes resulted in creation of two new slots on object,
2407tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002408the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002409
2410The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002411C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002412
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002413PyErr_Format has been updated to automatically calculate the size of
2414the buffer needed to hold the formatted result string. This change
2415prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002416
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002417New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002418
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002419PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2420that are the same as their non-Ex counterparts except they take an
2421extra flag argument that tells them to close the file when done.
2422
2423XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002424
Tim Peters8b092332000-09-05 20:15:25 +00002425
2426Windows Changes
2427---------------
2428
2429New popen2/popen3/peopen4 in os module (see Changed Modules above).
2430
2431os.popen is much more usable on Windows 95 and 98. See Microsoft
2432Knowledge Base article Q150956. The Win9x workaround described there
2433is implemented by the new w9xpopen.exe helper in the root of your
2434Python installation. Note that Python uses this internally; it is not
2435a standalone program.
2436
2437Administrator privileges are no longer required to install Python
2438on Windows NT or Windows 2000. If you have administrator privileges,
2439Python's registry info will be written under HKEY_LOCAL_MACHINE.
2440Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002441under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002442uses of Python, but will prevent some advanced uses from working
2443(for example, running a Python script as an NT service, or possibly
2444from CGI).
2445
2446[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2447installer; instead, it installs the needed Tcl/Tk files directly in the
2448Python directory. If you already have a Tcl/Tk installation, this
2449wastes some disk space (about 4 Megs) but avoids problems with
2450conflicting Tcl/Tk installations, and makes it much easier for Python
2451to ensure that Tcl/Tk can find all its files.
2452
2453[This was new in 1.6] The Windows installer now installs by default in
2454\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2455
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002456
2457Updates to the changes between 1.5.2 and 1.6
2458--------------------------------------------
2459
2460The 1.6 NEWS file can't be changed after the release is done, so here
2461is some late-breaking news:
2462
2463New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2464and changes to getlocale() and setlocale().
2465
2466The new module is now enabled per default.
2467
2468It is not true that the encodings codecs cannot be used for normal
2469strings: the string.encode() (which is also present on 8-bit strings
2470!) allows using them for 8-bit strings too, e.g. to convert files from
2471cp1252 (Windows) to latin-1 or vice-versa.
2472
2473Japanese codecs are available from Tamito KAJIYAMA:
2474http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2475
2476
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002477======================================================================