blob: 9ea0ac2d09396e48bbaf5356ae1a11994088a0d7 [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
Tim Petersb07352e2001-09-08 01:25:47 +000065Tools
66
Guido van Rossum624c8af2001-09-18 15:21:04 +000067- The "compiler" package has been brought up to date to the state of
68 Python 2.2 bytecode generation.
69
Tim Petersb07352e2001-09-08 01:25:47 +000070Build
71
Guido van Rossum624c8af2001-09-18 15:21:04 +000072- Large file support (LFS) is now automatic when the platform supports
73 it; no more manual configuration tweaks are needed. On Linux, at
74 least, it's possible to have a system whose C library supports large
75 files but whose kernel doesn't; in this case, large file support is
76 still enabled but doesn't do you any good unless you upgrade your
77 kernel or share your Python executable with another system whose
78 kernel has large file support.
79
80- The configure script now supplies plausible defaults in a
81 cross-compilation environment. This doesn't mean that the supplied
82 values are always correct, or that cross-compilation now works
83 flawlessly -- but it's a first step (and it shuts up most of
84 autoconf's warnings about AC_TRY_RUN).
85
86- The Unix build is now a bit less chatty, courtesy of the parser
87 generator. The build is completely silent (except for errors) when
88 using "make -s", thanks to a -q option to setup.py.
89
Tim Petersb07352e2001-09-08 01:25:47 +000090C API
91
Guido van Rossum624c8af2001-09-18 15:21:04 +000092- The "structmember" API now supports some new flag bits to deny read
93 and/or write access to attributes in restricted execution mode.
94
Tim Petersb07352e2001-09-08 01:25:47 +000095New platforms
96
Guido van Rossum624c8af2001-09-18 15:21:04 +000097- Compaq's iPAQ handheld, running the "familiar" Linux distribution
98 (http://familiar.handhelds.org).
99
Tim Petersb07352e2001-09-08 01:25:47 +0000100Tests
101
102Windows
103
Guido van Rossum624c8af2001-09-18 15:21:04 +0000104- Large file support now also works for files > 4GB, on filesystems
105 that support it (NTFS under Windows 2000).
106
Tim Petersb07352e2001-09-08 01:25:47 +0000107
Tim Petersedc99312001-08-22 21:36:50 +0000108What's New in Python 2.2a3?
109===========================
110
111Core
112
Tim Peters9fffa3e2001-09-04 05:14:19 +0000113- Conversion of long to float now raises OverflowError if the long is too
114 big to represent as a C double.
115
Tim Peters32f453e2001-09-03 08:35:41 +0000116- The 3-argument builtin pow() no longer allows a third non-None argument
117 if either of the first two arguments is a float, or if both are of
118 integer types and the second argument is negative (in which latter case
119 the arguments are converted to float, so this is really the same
120 restriction).
121
Tim Peters5d2b77c2001-09-03 05:47:38 +0000122- The builtin dir() now returns more information, and sometimes much
123 more, generally naming all attributes of an object, and all attributes
124 reachable from the object via its class, and from its class's base
125 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
126 an empty list. In 2.2a3,
127
128 >>> dir([])
129 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
130 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
131 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
132 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
133 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
134 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
135 'reverse', 'sort']
136
137 dir(module) continues to return only the module's attributes, though.
138
Tim Petersbdee63f2001-09-02 03:40:59 +0000139- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000140 than raising OverflowError. This is a partial implementation of PEP
141 237. You can use -Wdefault::OverflowWarning to enable a warning for
142 this situation, and -Werror::OverflowWarning to revert to the old
143 OverflowError exception.
144
Guido van Rossum61c345f2001-09-04 03:26:15 +0000145- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000146 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000147 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
148 -Qold, meaning the / operator has its classic meaning and no
149 warnings are issued. Using -Qwarn issues a run-time warning about
150 all uses of classic division for int and long arguments; -Qwarnall
151 also warns about classic division for float and complex arguments
152 (for use with fixdiv.py). Using -Qnew is questionable; it turns on
153 new division by default, but only in the __main__ module. You can
154 usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the
155 __main__ module new division, and warns about classic division
156 everywhere else.
Guido van Rossumae457142001-08-31 18:31:35 +0000157
Tim Petersbdee63f2001-09-02 03:40:59 +0000158- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000159 long, float, str, unicode, and tuple. (The types complex, list and
160 dictionary can also be subclassed; this was introduced earlier.)
161 Note that restrictions apply when subclassing immutable built-in
162 types: you can only affect the value of the instance by overloading
163 __new__. You can add mutable attributes, and the subclass instances
164 will have a __dict__ attribute, but you cannot change the "value"
165 (as implemented by the base class) of an immutable subclass instance
166 once it is created.
167
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000168- The dictionary constructor now takes an optional argument, a
169 mapping-like object, and initializes the dictionary from its
170 (key, value) pairs.
171
Tim Petersbdee63f2001-09-02 03:40:59 +0000172- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000173 "cooperative super calls" in a multiple inheritance setting. For an
174 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
175
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000176- A new built-in type, property, has been added. This enables the
177 creation of "properties". These are attributes implemented by
178 getter and setter functions (or only one of these for read-only or
179 write-only attributes), without the need to override __getattr__.
180 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000181
Tim Petersbdee63f2001-09-02 03:40:59 +0000182- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000183 liberalized, to allow leading zeroes. Examples of literals now
184 legal that were SyntaxErrors before:
185
186 00.0 0e3 0100j 07.5 00000000000000000008.
187
Tim Petersbdee63f2001-09-02 03:40:59 +0000188- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000189 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
190
Tim Petersedc99312001-08-22 21:36:50 +0000191Library
192
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000193- telnetlib includes symbolic names for the options, and support for
194 setting an option negotiation callback.
195
Tim Petersa40c7932001-09-05 22:36:56 +0000196- The new C standard no longer requires that math libraries set errno to
197 ERANGE on overflow. For platform libraries that exploit this new
198 freedom, Python's overflow-checking was wholly broken. A new overflow-
199 checking scheme attempts to repair that, but may not be reliable on all
200 platforms (C doesn't seem to provide anything both useful and portable
201 in this area anymore).
202
Martin v. Löwis44f86962001-09-05 13:44:54 +0000203- Asynchronous timeout actions are available through the new class
204 threading.Timer.
205
Tim Peters78526162001-09-05 00:53:45 +0000206- math.log and math.log10 now return sensible results for even huge
207 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
208
Tim Petersbdee63f2001-09-02 03:40:59 +0000209- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000210 currently held. See the docs for the imp module.
211
Tim Petersbdee63f2001-09-02 03:40:59 +0000212- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000213 dumps containing ints written on platforms where Python ints are 8 bytes.
214 When read on a box where Python ints are 4 bytes, such values are
215 converted to Python longs.
216
Tim Petersbdee63f2001-09-02 03:40:59 +0000217- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000218 code objects is no longer allowed. This plugs a security hole.
219
Steve Purcell6091cd62001-09-06 16:05:17 +0000220- unittest.TestResult instances no longer store references to tracebacks
221 generated by test failures. This prevents unexpected dangling references
222 to objects that should be garbage collected between tests.
223
Tim Petersedc99312001-08-22 21:36:50 +0000224Tools
225
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000226- Tools/scripts/fixdiv.py has been added which can be used to fix
227 division operators as per PEP 238.
228
Tim Petersedc99312001-08-22 21:36:50 +0000229Build
230
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000231- If you are an adventurous person using Mac OS X you may want to look at
232 Mac/OSX. There is a Makefile there that will build Python as a real Mac
233 application, which can be used for experimenting with Carbon or Cocoa.
234 Discussion of this on pythonmac-sig, please.
235
Tim Peters7eea37e2001-09-04 22:08:56 +0000236C API
237
238- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000239
Tim Peters9fffa3e2001-09-04 05:14:19 +0000240- Note that PyLong_AsDouble can fail! This has always been true, but no
241 callers checked for it. It's more likely to fail now, because overflow
242 errors are properly detected now. The proper way to check:
243
244 double x = PyLong_AsDouble(some_long_object);
245 if (x == -1.0 && PyErr_Occurred()) {
246 /* The conversion failed. */
247 }
248
Tim Petersbdee63f2001-09-02 03:40:59 +0000249- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000250 compile but will not participate in GC. To upgrade an extension
251 module:
252
253 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000254
Neil Schemenauer4042c692001-08-30 15:38:01 +0000255 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
256 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000257
Neil Schemenauer4042c692001-08-30 15:38:01 +0000258 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
259 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +0000260
Neil Schemenauer4042c692001-08-30 15:38:01 +0000261 - remove PyGC_HEAD_SIZE from object size calculations
262
263 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
264
Tim Petersbdee63f2001-09-02 03:40:59 +0000265- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +0000266 These can be used safely to construct string objects from a
267 sprintf-style format string (similar to the format string supported
268 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +0000269
Tim Petersedc99312001-08-22 21:36:50 +0000270New platforms
271
Tim Petersb7da0902001-09-02 23:01:43 +0000272- Stephen Hansen contributed patches sufficient to get a clean compile
273 under Borland C (Windows), but he reports problems running it and ran
274 out of time to complete the port. Volunteers? Expect a MemoryError
275 when importing the types module; this is probably shallow, and
276 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +0000277
Tim Petersedc99312001-08-22 21:36:50 +0000278Tests
279
280Windows
281
Tim Peters6e13a562001-09-06 00:32:15 +0000282- Large file support is now enabled on Win32 platforms as well as on
283 Win64. This means that, for example, you can use f.tell() and f.seek()
284 to manipulate files larger than 2 gigabytes (provided you have enough
285 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +0000286 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
287 filesize limit, and large file support makes no difference there.
288 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
289 NTFS has no practical limit on file size, and files of any size can be
290 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +0000291
Tim Petersbdee63f2001-09-02 03:40:59 +0000292- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +0000293 points to command.com (patch from Brian Quinlan).
294
Tim Petersedc99312001-08-22 21:36:50 +0000295
Tim Peters20f51a72001-07-21 02:31:40 +0000296What's New in Python 2.2a2?
297===========================
298
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000299Build
300
Barry Warsaw18b2ecf2001-08-22 20:26:56 +0000301- Tim Peters developed a brand new Windows installer using Wise 8.1,
302 generously donated to us by Wise Solutions.
303
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000304- configure supports a new option --enable-unicode, with the values
305 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
306 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000307
Jack Jansen32ce0cd2001-08-21 19:28:20 +0000308- A new configure option --enable-framework builds a Mac OS X framework,
309 which "make frameworkinstall" will install. This provides a starting
310 point for more mac-like functionality, join pythonmac-sig@python.org
311 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000312
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000313- The NeXT platform is no longer supported.
314
315- The `new' module is now statically linked.
316
Tim Peters0afb6092001-08-15 06:06:44 +0000317Tools
318
319- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +0000320 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +0000321 the module docstring for details.
322
Tim Peters20f51a72001-07-21 02:31:40 +0000323Tests
324
Tim Peters5e824c32001-08-12 22:25:01 +0000325- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000326 platforms, allowing to give clearer test result output. regrtest
327 also has optional --use/-u switch to run normally disabled tests
328 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +0000329
Tim Peters20f51a72001-07-21 02:31:40 +0000330- Several new tests in the standard test suite, with special thanks to
331 Nick Mathewson.
332
333Core
334
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000335- The floor division operator // has been added as outlined in PEP
336 238. The / operator still provides classic division (and will until
337 Python 3.0) unless "from __future__ import division" is included, in
338 which case the / operator will provide true division. The operator
339 module provides truediv() and floordiv() functions. Augmented
340 assignment variants are included, as are the equivalent overloadable
341 methods and C API methods. See the PEP for a full discussion:
342 <http://python.sf.net/peps/pep-0238.html>
343
Tim Peters6cd6a822001-08-17 22:11:27 +0000344- Future statements are now effective in simulated interactive shells
345 (like IDLE). This should "just work" by magic, but read Michael
346 Hudson's "Future statements in simulated shells" PEP 264 for full
347 details: <http://python.sf.net/peps/pep-0264.html>.
348
Guido van Rossumf86ddd22001-08-17 21:21:04 +0000349- The type/class unification (PEP 252-253) was integrated into the
350 trunk and is not so tentative any more (the exact specification of
351 some features is still tentative). A lot of work has done on fixing
352 bugs and adding robustness and features (performance still has to
353 come a long way).
354
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000355- Warnings about a mismatch in the Python API during extension import
356 now use the Python warning framework (which makes it possible to
357 write filters for these warnings).
358
Barry Warsaw9b3be7f2001-08-14 18:35:02 +0000359- A function's __dict__ (aka func_dict) will now always be a
360 dictionary. It used to be possible to delete it or set it to None,
361 but now both actions raise TypeErrors. It is still legal to set it
362 to a dictionary object. Getting func.__dict__ before any attributes
363 have been assigned now returns an empty dictionary instead of None.
364
Guido van Rossum32aa5d22001-09-05 18:43:35 +0000365- A new command line option, -E, was added which disables the use of
366 all environment variables, or at least those that are specifically
367 significant to Python. Usually those have a name starting with
368 "PYTHON". This was used to fix a problem where the tests fail if
369 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
370 older distribution.
371
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000372Library
373
Tim Peters5e824c32001-08-12 22:25:01 +0000374- New class Differ and new functions ndiff() and restore() in difflib.py.
375 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +0000376 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +0000377
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000378- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
379 value using the minimal quoting required for the value; more
380 reliable than using xml.sax.saxutils.escape() for attribute values.
381
382- Readline completion support for cmd.Cmd was added.
383
Barry Warsaw6f3410d2001-08-22 04:08:41 +0000384- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
385
386- Added function threading.BoundedSemaphore()
387
388- Added Ka-Ping Yee's cgitb.py module.
389
390- The `new' module now exposes the CO_xxx flags.
391
Marc-André Lemburgd6277912001-07-31 14:42:42 +0000392New platforms
393
394C API
395
Marc-André Lemburg888fac02001-07-31 14:24:31 +0000396- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
397 which provide a cross-platform implementations for the
398 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
399 the standard sprintf() and vsprintf() C lib APIs, these versions
400 apply bounds checking on the used buffer which enhances protection
401 against buffer overruns.
402
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000403- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +0000404 and extensions using different Unicode widths is rendered next to
405 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +0000406 will result in an ImportError. Unicode extensions writers must make
407 sure to check the Unicode width compatibility in their extensions by
408 using at least one of the mangled Unicode APIs in the extension.
409
Martin v. Löwis339d0f72001-08-17 18:39:25 +0000410- Two new flags METH_NOARGS and METH_O are available in method definition
411 tables to simplify implementation of methods with no arguments and a
412 single untyped argument. Calling such methods is more efficient than
413 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
414 deprecated.
415
Tim Petersc1731372001-08-04 08:12:36 +0000416Windows
417
418- "import module" now compiles module.pyw if it exists and nothing else
419 relevant is found.
420
Tim Peters20f51a72001-07-21 02:31:40 +0000421
Guido van Rossum55a78992001-07-17 17:22:32 +0000422What's New in Python 2.2a1?
Tim Petersf553f892001-05-01 20:45:31 +0000423===========================
424
425Core
Tim Petersa814db52001-05-14 07:05:58 +0000426
Tim Peters6d6c1a32001-08-02 04:15:00 +0000427- TENTATIVELY, a large amount of code implementing much of what's
428 described in PEP 252 (Making Types Look More Like Classes) and PEP
429 253 (Subtyping Built-in Types) was added. This will be released
430 with Python 2.2a1. Documentation will be provided separately
431 through http://www.python.org/2.2/. The purpose of releasing this
432 with Python 2.2a1 is to test backwards compatibility. It is
433 possible, though not likely, that a decision is made not to release
434 this code as part of 2.2 final, if any serious backwards
435 incompapatibilities are found during alpha testing that cannot be
436 repaired.
437
Guido van Rossum55a78992001-07-17 17:22:32 +0000438- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +0000439 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +0000440 more 'yield' statements. See PEP 255. Since this adds a new
441 keyword to the language, this feature must be enabled by including a
442 future statement: "from __future__ import generators" (see PEP 236).
443 Generators will become a standard feature in a future release
444 (probably 2.3). Without this future statement, 'yield' remains an
445 ordinary identifier, but a warning is issued each time it is used.
446 (These warnings currently don't conform to the warnings framework of
447 PEP 230; we intend to fix this in 2.2a2.)
448
Marc-André Lemburg12e74b32001-05-22 08:58:23 +0000449- The UTF-16 codec was modified to be more RFC compliant. It will now
450 only remove BOM characters at the start of the string and then
451 only if running in native mode (UTF-16-LE and -BE won't remove a
452 leading BMO character).
453
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000454- Strings now have a new method .decode() to complement the already
455 existing .encode() method. These two methods provide direct access
456 to the corresponding decoders and encoders of the registered codecs.
457
458 To enhance the usability of the .encode() method, the special
459 casing of Unicode object return values was dropped (Unicode objects
460 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +0000461
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000462 Both methods will now return whatever the codec in charge of the
463 requested encoding returns as object, e.g. Unicode codecs will
464 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
465 will return u"äöü"). This enables codec writer to create codecs
466 for various simple to use conversions.
467
468 New codecs were added to demonstrate these new features (the .encode()
469 and .decode() columns indicate the type of the returned objects):
470
471 Name | .encode() | .decode() | Description
472 ----------------------------------------------------------------------
473 uu | string | string | UU codec (e.g. for email)
474 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +0000475 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +0000476 zlib | string | string | zlib compression
477 hex | string | string | 2-byte hex codec
478 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
479
Mark Hammond2a0af792001-05-14 03:09:36 +0000480- Some operating systems now support the concept of a default Unicode
481 encoding for file system operations. Notably, Windows supports 'mbcs'
482 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000483 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +0000484 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000485
486 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +0000487 functions that return filenames (such as os.listdir()) to return Python
488 string objects pre-encoded using the default file system encoding for
489 the platform. As this encoding is likely to be different from Python's
490 default encoding, converting this name to a Unicode object before passing
491 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +0000492 would attempt to use its default encoding (generally ASCII) rather than
493 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +0000494
Tim Petersa814db52001-05-14 07:05:58 +0000495 In general, this change simply removes surprises when working with
496 Unicode and the file system, making these operations work as you expect,
497 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +0000498 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +0000499
Tim Peters61dff2b2001-05-08 15:43:37 +0000500- Float (and complex) literals in source code were evaluated to full
501 precision only when running from a .py file; the same code loaded from a
502 .pyc (or .pyo) file could suffer numeric differences starting at about the
503 12th significant decimal digit. For example, on a machine with IEEE-754
504 floating arithmetic,
505
506 x = 9007199254740992.0
507 print long(x)
508
509 printed 9007199254740992 if run directly from .py, but 9007199254740000
510 if from a compiled (.pyc or .pyo) file. This was due to marshal using
511 str(float) instead of repr(float) when building code objects. marshal
512 now uses repr(float) instead, which should reproduce floats to full
513 machine precision (assuming the platform C float<->string I/O conversion
514 functions are of good quality).
515
516 This may cause floating-point results to change in some cases, and
517 usually for the better, but may also cause numerically unstable
518 algorithms to break.
519
Tim Peters2f228e72001-05-13 00:19:31 +0000520- The implementation of dicts suffers fewer collisions, which has speed
521 benefits. However, the order in which dict entries appear in dict.keys(),
522 dict.values() and dict.items() may differ from previous releases for a
523 given dict. Nothing is defined about this order, so no program should
524 rely on it. Nevertheless, it's easy to write test cases that rely on the
525 order by accident, typically because of printing the str() or repr() of a
526 dict to an "expected results" file. See Lib/test/test_support.py's new
527 sortdict(dict) function for a simple way to display a dict in sorted
528 order.
529
Tim Peters7a3bfc32001-06-12 01:22:22 +0000530- Many other small changes to dicts were made, resulting in faster
531 operation along the most common code paths.
532
Guido van Rossum10315822001-05-01 20:54:30 +0000533- Dictionary objects now support the "in" operator: "x in dict" means
534 the same as dict.has_key(x).
535
Barry Warsaw51acc8d2001-06-26 20:12:50 +0000536- The update() method of dictionaries now accepts generic mapping
537 objects. Specifically the argument object must support the .keys()
538 and __getitem__() methods. This allows you to say, for example,
539 {}.update(UserDict())
540
Guido van Rossum10315822001-05-01 20:54:30 +0000541- Iterators were added; this is a generalized way of providing values
542 to a for loop. See PEP 234. There's a new built-in function iter()
543 to return an iterator. There's a new protocol to get the next value
544 from an iterator using the next() method (in Python) or the
545 tp_iternext slot (in C). There's a new protocol to get iterators
546 using the __iter__() method (in Python) or the tp_iter slot (in C).
547 Iterating (i.e. a for loop) over a dictionary generates its keys.
548 Iterating over a file generates its lines.
549
Tim Petersf553f892001-05-01 20:45:31 +0000550- The following functions were generalized to work nicely with iterator
551 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +0000552 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +0000553 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
554 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +0000555 join() method of strings
556 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +0000557 'x in y' and 'x not in y' (PySequence_Contains() in C API)
558 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +0000559 right-hand side of assignment statements with multiple targets, such as
560 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +0000561
Tim Petersd85e1022001-05-11 21:51:48 +0000562- Accessing module attributes is significantly faster (for example,
563 random.random or os.path or yourPythonModule.yourAttribute).
564
Tim Peterse63415e2001-05-08 04:38:29 +0000565- Comparing dictionary objects via == and != is faster, and now works even
566 if the keys and values don't support comparisons other than ==.
567
Tim Peters95bf9392001-05-10 08:32:44 +0000568- Comparing dictionaries in ways other than == and != is slower: there were
569 insecurities in the dict comparison implementation that could cause Python
570 to crash if the element comparison routines for the dict keys and/or
571 values mutated the dicts. Making the code bulletproof slowed it down.
572
Tim Peterseb28ef22001-06-02 05:27:19 +0000573- Collisions in dicts are resolved via a new approach, which can help
574 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +0000575 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +0000576 faster now. Thanks to Christian Tismer for pointing out the cause and
577 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +0000578
Tim Peters52e155e2001-06-16 05:42:57 +0000579- repr() is much faster for large containers (dict, list, tuple).
580
581
Tim Petersa814db52001-05-14 07:05:58 +0000582Library
583
Fred Drake960fdf92001-07-20 18:38:26 +0000584- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
585 were added to the string module. These a locale-indenpendent
586 constants, unlike letters, lowercase, and uppercase. These are now
587 use in appropriate locations in the standard library.
588
Martin v. Löwisf0473d52001-07-18 16:17:16 +0000589- The flags used in dlopen calls can now be configured using
590 sys.setdlopenflags and queried using sys.getdlopenflags.
591
Guido van Rossumc7e4aca2001-07-12 11:54:37 +0000592- Fredrik Lundh's xmlrpclib is now a standard library module. This
593 provides full client-side XML-RPC support. In addition,
594 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
595 one asyncore-based). Thanks to Eric Raymond for the documentation.
596
Guido van Rossum643d3912001-07-05 14:46:25 +0000597- The xrange() object is simplified: it no longer supports slicing,
598 repetition, comparisons, efficient 'in' checking, the tolist()
599 method, or the start, stop and step attributes. See PEP 260.
600
Martin v. Löwisebf94db2001-06-06 06:25:40 +0000601- A new function fnmatch.filter to filter lists of file names was added.
602
Barry Warsawffd674d2001-05-22 16:00:10 +0000603- calendar.py uses month and day names based on the current locale.
604
Guido van Rossum2e0a6542001-05-15 02:14:44 +0000605- strop is now *really* obsolete (this was announced before with 1.6),
606 and issues DeprecationWarning when used (except for the four items
607 that are still imported into string.py).
608
Tim Petersa814db52001-05-14 07:05:58 +0000609- Cookie.py now sorts key+value pairs by key in output strings.
610
611- pprint.isrecursive(object) didn't correctly identify recursive objects.
612 Now it does.
613
Tim Peters95b3f782001-05-14 18:39:41 +0000614- pprint functions now much faster for large containers (tuple, list, dict).
615
Tim Peters7b9542a2001-06-10 23:40:19 +0000616- New 'q' and 'Q' format codes in the struct module, corresponding to C
617 types "long long" and "unsigned long long" (on Windows, __int64). In
618 native mode, these can be used only when the platform C compiler supports
619 these types (when HAVE_LONG_LONG is #define'd by the Python config
620 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +0000621 In standard mode, 'q' and 'Q' are supported on all platforms, and are
622 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +0000623
Guido van Rossum83213cc2001-06-12 16:48:52 +0000624- The site module installs a new built-in function 'help' that invokes
625 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
626 it displays a message reminding the user to use 'help()' or
627 'help(object)'.
628
Tim Petersa814db52001-05-14 07:05:58 +0000629Tests
630
631- New test_mutants.py runs dict comparisons where the key and value
632 comparison operators mutute the dicts randomly during comparison. This
633 rapidly causes Python to crash under earlier releases (not for the faint
634 of heart: it can also cause Win9x to freeze or reboot!).
635
636- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +0000637 pprint.isreadable() return sensible results. Also verifies that simple
638 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +0000639
Tim Peters4324aa32001-05-28 22:30:08 +0000640C API
641
642- Removed the unused last_is_sticky argument from the internal
643 _PyTuple_Resize(). If this affects you, you were cheating.
644
645
Guido van Rossum55a78992001-07-17 17:22:32 +0000646======================================================================
647
648
Guido van Rossumffe13be2001-04-16 18:46:45 +0000649What's New in Python 2.1 (final)?
650=================================
651
652We only changed a few things since the last release candidate, all in
653Python library code:
654
655- A bug in the locale module was fixed that affected locales which
656 define no grouping for numeric formatting.
657
658- A few bugs in the weakref module's implementations of weak
659 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
660 and the test suite was updated to check for these bugs.
661
662- An old bug in the os.path.walk() function (introduced in Python
663 2.0!) was fixed: a non-existent file would cause an exception
664 instead of being ignored.
665
666- Fixed a few bugs in the new symtable module found by Neil Norwitz's
667 PyChecker.
668
669
Guido van Rossum5b08f132001-04-16 02:05:23 +0000670What's New in Python 2.1c2?
671===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +0000672
Guido van Rossum5b08f132001-04-16 02:05:23 +0000673A flurry of small changes, and one showstopper fixed in the nick of
674time made it necessary to release another release candidate. The list
675here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +0000676
Guido van Rossum5b08f132001-04-16 02:05:23 +0000677Core
Guido van Rossum4fb60362001-04-13 00:46:14 +0000678
Guido van Rossum5b08f132001-04-16 02:05:23 +0000679- Tim discovered a nasty bug in the dictionary code, caused by
680 PyDict_Next() calling dict_resize(), and the GC code's use of
681 PyDict_Next() violating an assumption in dict_items(). This was
682 fixed with considerable amounts of band-aid, but the net effect is a
683 saner and more robust implementation.
684
685- Made a bunch of symbols static that were accidentally global.
686
687Build and Ports
688
689- The setup.py script didn't check for a new enough version of zlib
690 (1.1.3 is needed). Now it does.
691
692- Changed "make clean" target to also remove shared libraries.
693
694- Added a more general warning about the SGI Irix optimizer to README.
695
696Library
697
698- Fix a bug in urllib.basejoin("http://host", "../file.html") which
699 omitted the slash between host and file.html.
700
701- The mailbox module's _Mailbox class contained a completely broken
702 and undocumented seek() method. Ripped it out.
703
704- Fixed a bunch of typos in various library modules (urllib2, smtpd,
705 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
706
707- Fixed a few last-minute bugs in unittest.
708
709Extensions
710
711- Reverted the patch to the OpenSSL code in socketmodule.c to support
712 RAND_status() and the EGD, and the subsequent patch that tried to
713 fix it for pre-0.9.5 versions; the problem with the patch is that on
714 some systems it issues a warning whenever socket is imported, and
715 that's unacceptable.
716
717Tests
718
719- Fixed the pickle tests to work with "import test.test_pickle".
720
721- Tweaked test_locale.py to actually run the test Windows.
722
723- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
724 not "wb" (which is not a valid mode at all).
725
726- Fix pstats browser crashes. Import readline if it exists to make
727 the user interface nicer.
728
729- Add "import thread" to the top of test modules that import the
730 threading module (test_asynchat and test_threadedtempfile). This
731 prevents test failures caused by a broken threading module resulting
732 from a previously caught failed import.
733
734- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
735 needed on some platforms (e.g. Solaris 8) when the tests are run
736 twice in succession.
737
738- Skip rather than fail test_sunaudiodev if no audio device is found.
739
740
741What's New in Python 2.1c1?
742===========================
743
744This list was significantly updated when 2.1c2 was released; the 2.1c1
745release didn't mention most changes that were actually part of 2.1c1:
746
747Legal
748
749- Copyright was assigned to the Python Software Foundation (PSF) and a
750 PSF license (very similar to the CNRI license) was added.
751
752- The CNRI copyright notice was updated to include 2001.
753
754Core
Barry Warsaw11e89c72001-04-11 20:37:57 +0000755
Guido van Rossumc9932722001-04-12 02:31:27 +0000756- After a public outcry, assignment to __debug__ is no longer illegal;
757 instead, a warning is issued. It will become illegal in 2.2.
758
Guido van Rossum5b08f132001-04-16 02:05:23 +0000759- Fixed a core dump with "%#x" % 0, and changed the semantics so that
760 "%#x" now always prepends "0x", even if the value is zero.
761
762- Fixed some nits in the bytecode compiler.
763
764- Fixed core dumps when calling certain kinds of non-functions.
765
766- Fixed various core dumps caused by reference count bugs.
767
768Build and Ports
769
770- Use INSTALL_SCRIPT to install script files.
771
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000772- New port: SCO Unixware 7, by Billy G. Allie.
773
Guido van Rossum5b08f132001-04-16 02:05:23 +0000774- Updated RISCOS port.
775
776- Updated BeOS port and notes.
777
778- Various other porting problems resolved.
779
780Library
781
782- The TERMIOS and SOCKET modules are now truly obsolete and
783 unnecessary. Their symbols are incorporated in the termios and
784 socket modules.
785
786- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
787 better tests for pickling.
788
789- threading: make Condition.wait() robust against KeyboardInterrupt.
790
791- zipfile: add support to zipfile to support opening an archive
792 represented by an open file rather than a file name. Fix bug where
793 the archive was not properly closed. Fixed a bug in this bugfix
794 where flush() was called for a read-only file.
795
796- imputil: added an uninstall() method to the ImportManager.
797
798- Canvas: fixed bugs in lower() and tkraise() methods.
799
800- SocketServer: API change (added overridable close_request() method)
801 so that the TCP server can explicitly close the request.
802
803- pstats: Eric Raymond added a simple interactive statistics browser,
804 invoked when the module is run as a script.
805
806- locale: fixed a problem in format().
807
808- webbrowser: made it work when the BROWSER environment variable has a
809 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
810 KDE 2. Fixed some other nits.
811
812- unittest: changes to allow using a different exception than
813 AssertionError, and added a few more function aliases. Some other
814 small changes.
815
816- urllib, urllib2: fixed redirect problems and a coupleof other nits.
817
818- asynchat: fixed a critical bug in asynchat that slipped through the
819 2.1b2 release. Fixed another rare bug.
820
821- Fix some unqualified except: clauses (always a bad code example).
822
823XML
824
825- pyexpat: new API get_version_string().
826
827- Fixed some minidom bugs.
828
829Extensions
830
831- Fixed a core dump in _weakref. Removed the weakref.mapping()
832 function (it adds nothing to the API).
833
834- Rationalized the use of header files in the readline module, to make
835 it compile (albeit with some warnings) with the very recent readline
836 4.2, without breaking for earlier versions.
837
838- Hopefully fixed a buffering problem in linuxaudiodev.
839
840- Attempted a fix to make the OpenSSL support in the socket module
841 work again with pre-0.9.5 versions of OpenSSL.
842
843Tests
844
845- Added a test case for asynchat and asyncore.
846
847- Removed coupling between tests where one test failing could break
848 another.
849
850Tools
851
852- Ping added an interactive help browser to pydoc, fixed some nits
853 in the rest of the pydoc code, and added some features to his
854 inspect module.
855
856- An updated python-mode.el version 4.1 which integrates Ken
857 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
858 much nicer in XEmacs and Emacs. When stepping through your program
859 with pdb, in either the shell window or the *Python* window, the
860 source file and line will be tracked by an arrow. Very cool!
861
862- IDLE: syntax warnings in interactive mode are changed into errors.
863
864- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +0000865 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +0000866
867- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +0000868
Barry Warsaw11e89c72001-04-11 20:37:57 +0000869
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000870What's New in Python 2.1 beta 2?
871================================
872
Guido van Rossum053ae352001-03-22 14:17:21 +0000873(Unlisted are many fixed bugs, more documentation, etc.)
874
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000875Core language, builtins, and interpreter
876
Guido van Rossum053ae352001-03-22 14:17:21 +0000877- The nested scopes work (enabled by "from __future__ import
878 nested_scopes") is completed; in particular, the future now extends
879 into code executed through exec, eval() and execfile(), and into the
880 interactive interpreter.
881
882- When calling a base class method (e.g. BaseClass.__init__(self)),
883 this is now allowed even if self is not strictly spoken a class
884 instance (e.g. when using metaclasses or the Don Beaudry hook).
885
886- Slice objects are now comparable but not hashable; this prevents
887 dict[:] from being accepted but meaningless.
888
889- Complex division is now calculated using less braindead algorithms.
890 This doesn't change semantics except it's more likely to give useful
891 results in extreme cases. Complex repr() now uses full precision
892 like float repr().
893
894- sgmllib.py now calls handle_decl() for simple <!...> declarations.
895
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000896- It is illegal to assign to the name __debug__, which is set when the
897 interpreter starts. It is effectively a compile-time constant.
898
899- A warning will be issued if a global statement for a variable
900 follows a use or assignment of that variable.
901
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000902Standard library
903
Guido van Rossum053ae352001-03-22 14:17:21 +0000904- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
905 inspired by JUnit), is now part of the standard library. You now
906 have a choice of two testing frameworks: unittest requires you to
907 write testcases as separate code, doctest gathers them from
908 docstrings. Both approaches have their advantages and
909 disadvantages.
910
911- A new module Tix was added, which wraps the Tix extension library
912 for Tk. With that module, it is not necessary to statically link
913 Tix with _tkinter, since Tix will be loaded with Tcl's "package
914 require" command. See Demo/tix/.
915
916- tzparse.py is now obsolete.
917
918- In gzip.py, the seek() and tell() methods are removed -- they were
919 non-functional anyway, and it's better if callers can test for their
920 existence with hasattr().
921
922Python/C API
923
924- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
925 that's already in the dictionary during a PyDict_Next() iteration.
926 This used to fail occasionally when a dictionary resize operation
927 could be triggered that would rehash all the keys. All other
928 modifications to the dictionary are still off-limits during a
929 PyDict_Next() iteration!
930
931- New extended APIs related to passing compiler variables around.
932
933- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
934 implement isinstance() and issubclass().
935
936- Py_BuildValue() now has a "D" conversion to create a Python complex
937 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +0000938
Fred Drake4e262a92001-03-22 18:26:47 +0000939- Extensions types which support weak references must now set the
940 field allocated for the weak reference machinery to NULL themselves;
941 this is done to avoid the cost of checking each object for having a
942 weakly referencable type in PyObject_INIT(), since most types are
943 not weakly referencable.
944
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000945- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
946 free variables and cell variables to and from the frame's f_locals.
947
948- Variants of several functions defined in pythonrun.h have been added
949 to support the nested_scopes future statement. The variants all end
950 in Flags and take an extra argument, a PyCompilerFlags *; examples:
951 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
952 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +0000953 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +0000954
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000955Distutils
956
957- the sdist command now writes a PKG-INFO file, as described in PEP 241,
958 into the release tree.
959
Tim Peters0e57abf2001-05-02 07:39:38 +0000960- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000961 (an uninstaller, more customization of the installer's display)
962
963- from Jack Jansen: added Mac-specific code to generate a dialog for
964 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +0000965 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000966 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +0000967
968- added 'platforms' and 'keywords' to the set of metadata that can be
969 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +0000970
971- applied patches from Jason Tishler to make the compiler class work with
972 Cygwin.
973
974
Tim Peters2fe289a2001-03-01 22:19:38 +0000975What's New in Python 2.1 beta 1?
976================================
Tim Petersd66595f2001-02-04 03:09:53 +0000977
978Core language, builtins, and interpreter
979
Guido van Rossum9d0fbde2001-03-02 14:00:32 +0000980- Following an outcry from the community about the amount of code
981 broken by the nested scopes feature introduced in 2.1a2, we decided
982 to make this feature optional, and to wait until Python 2.2 (or at
983 least 6 months) to make it standard. The option can be enabled on a
984 per-module basis by adding "from __future__ import nested_scopes" at
985 the beginning of a module (before any other statements, but after
986 comments and an optional docstring). See PEP 236 (Back to the
987 __future__) for a description of the __future__ statement. PEP 227
988 (Statically Nested Scopes) has been updated to reflect this change,
989 and to clarify the semantics in a number of endcases.
990
991- The nested scopes code, when enabled, has been hardened, and most
992 bugs and memory leaks in it have been fixed.
993
994- Compile-time warnings are now generated for a number of conditions
995 that will break or change in meaning when nested scopes are enabled:
996
997 - Using "from...import *" or "exec" without in-clause in a function
998 scope that also defines a lambda or nested function with one or
999 more free (non-local) variables. The presence of the import* or
1000 bare exec makes it impossible for the compiler to determine the
1001 exact set of local variables in the outer scope, which makes it
1002 impossible to determine the bindings for free variables in the
1003 inner scope. To avoid the warning about import *, change it into
1004 an import of explicitly name object, or move the import* statement
1005 to the global scope; to avoid the warning about bare exec, use
1006 exec...in... (a good idea anyway -- there's a possibility that
1007 bare exec will be deprecated in the future).
1008
1009 - Use of a global variable in a nested scope with the same name as a
1010 local variable in a surrounding scope. This will change in
1011 meaning with nested scopes: the name in the inner scope will
1012 reference the variable in the outer scope rather than the global
1013 of the same name. To avoid the warning, either rename the outer
1014 variable, or use a global statement in the inner function.
1015
Neil Schemenauera35c6882001-02-27 04:45:05 +00001016- An optional object allocator has been included. This allocator is
1017 optimized for Python objects and should be faster and use less memory
1018 than the standard system allocator. It is not enabled by default
1019 because of possible thread safety problems. The allocator is only
1020 protected by the Python interpreter lock and it is possible that some
1021 extension modules require a thread safe allocator. The object
1022 allocator can be enabled by providing the "--with-pymalloc" option to
1023 configure.
1024
Tim Petersd66595f2001-02-04 03:09:53 +00001025Standard library
1026
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001027- pyexpat now detects the expat version if expat.h defines it. A
1028 number of additional handlers are provided, which are only available
1029 since expat 1.95. In addition, the methods SetParamEntityParsing and
1030 GetInputContext of Parser objects are available with 1.95.x
1031 only. Parser objects now provide the ordered_attributes and
1032 specified_attributes attributes. A new module expat.model was added,
1033 which offers a number of additional constants if 1.95.x is used.
1034
1035- xml.dom offers the new functions registerDOMImplementation and
1036 getDOMImplementation.
1037
1038- xml.dom.minidom offers a toprettyxml method. A number of DOM
1039 conformance issues have been resolved. In particular, Element now
1040 has an hasAttributes method, and the handling of namespaces was
1041 improved.
1042
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001043- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1044 getting information about live Python code, and pydoc.py, a module
1045 for interactively converting docstrings to HTML or text.
1046 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001047 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001048 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1049 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001050
Tim Peters1eff7962001-03-01 02:31:33 +00001051- New library module difflib.py, primarily packaging the SequenceMatcher
1052 class at the heart of the popular ndiff.py file-comparison tool.
1053
1054- doctest.py (a framework for verifying Python code examples in docstrings)
1055 is now part of the std library.
1056
Tim Petersd66595f2001-02-04 03:09:53 +00001057Windows changes
1058
Guido van Rossume3955a82001-03-02 14:05:59 +00001059- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1060 small GUI that lets you browse the module docstrings using your
1061 default web browser.
1062
Tim Peters1eff7962001-03-01 02:31:33 +00001063- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1064 Platforms) is implemented. See
1065
1066 http://python.sourceforge.net/peps/pep-0235.html
1067
1068 for full details, especially the "Current Lower-Left Semantics" section.
1069 The new Windows import rules are simpler than before:
1070
1071 A. If the PYTHONCASEOK environment variable exists, same as
1072 before: silently accept the first case-insensitive match of any
1073 kind; raise ImportError if none found.
1074
1075 B. Else search sys.path for the first case-sensitive match; raise
1076 ImportError if none found.
1077
1078 The same rules have been implented on other platforms with case-
1079 insensitive but case-preserving filesystems too (including Cygwin, and
1080 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001081
Tim Peters25a9ce32001-02-19 07:06:36 +00001082- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1083 what it's supposed to do (and does do under NT and 2000) via direct
1084 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001085 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001086 all Win9x systems before.
1087
Tim Peters1eff7962001-03-01 02:31:33 +00001088- Build: Subproject _test (effectively) renamed to _testcapi.
1089
Tim Peters2fe289a2001-03-01 22:19:38 +00001090New platforms
1091
1092- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1093 Thanks to Steven Majewski!
1094
1095- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1096 Tishler!
1097
Guido van Rossum9089b272001-03-02 06:49:50 +00001098- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1099 Schwertberger! See RISCOS/README for more information -- it seems
1100 that because of the bizarre filename conventions on RISCOS, no port
1101 to that platform is easy. Note that the new variable os.endsep is
1102 silently supported in order to make life easier on this platform,
1103 but we don't advertise it because it's not worth for most folks to
1104 care about RISCOS portability.
1105
Tim Peters25a9ce32001-02-19 07:06:36 +00001106
Tim Petersd7b5e882001-01-25 03:36:26 +00001107What's New in Python 2.1 alpha 2?
1108=================================
Tim Peters40ead762001-01-27 05:35:26 +00001109
Tim Petersd7b5e882001-01-25 03:36:26 +00001110Core language, builtins, and interpreter
1111
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001112- Scopes nest. If a name is used in a function or class, but is not
1113 local, the definition in the nearest enclosing function scope will
1114 be used. One consequence of this change is that lambda statements
1115 could reference variables in the namespaces where the lambda is
1116 defined. In some unusual cases, this change will break code.
1117
1118 In all previous version of Python, names were resolved in exactly
1119 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001120 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001121 function A is defined within a function B, the names bound in B are
1122 not visible in A. The new rules make names bound in B visible in A,
1123 unless A contains a name binding that hides the binding in B.
1124
1125 Section 4.1 of the reference manual describes the new scoping rules
1126 in detail. The test script in Lib/test/test_scope.py demonstrates
1127 some of the effects of the change.
1128
1129 The new rules will cause existing code to break if it defines nested
1130 functions where an outer function has local variables with the same
1131 name as globals or builtins used by the inner function. Example:
1132
1133 def munge(str):
1134 def helper(x):
1135 return str(x)
1136 if type(str) != type(''):
1137 str = helper(str)
1138 return str.strip()
1139
1140 Under the old rules, the name str in helper() is bound to the
1141 builtin function str(). Under the new rules, it will be bound to
1142 the argument named str and an error will occur when helper() is
1143 called.
1144
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001145- The compiler will report a SyntaxError if "from ... import *" occurs
1146 in a function or class scope. The language reference has documented
1147 that this case is illegal, but the compiler never checked for it.
1148 The recent introduction of nested scope makes the meaning of this
1149 form of name binding ambiguous. In a future release, the compiler
1150 may allow this form when there is no possibility of ambiguity.
1151
Tim Peters40ead762001-01-27 05:35:26 +00001152- repr(string) is easier to read, now using hex escapes instead of octal,
1153 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1154
1155 >>> "\texample \r\n" + chr(0) + chr(255)
1156 '\texample \r\n\x00\xff' # in 2.1
1157 '\011example \015\012\000\377' # in 2.0
1158
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001159- Functions are now compared and hashed by identity, not by value, since
1160 the func_code attribute is writable.
1161
Fred Drakefb9d7122001-02-01 20:00:40 +00001162- Weak references (PEP 205) have been added. This involves a few
1163 changes in the core, an extension module (_weakref), and a Python
1164 module (weakref). The weakref module is the public interface. It
1165 includes support for "explicit" weak references, proxy objects, and
1166 mappings with weakly held values.
1167
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001168- A 'continue' statement can now appear in a try block within the body
1169 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001170 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001171
Tim Petersd7b5e882001-01-25 03:36:26 +00001172Standard library
1173
Barry Warsaw30dbd142001-01-31 22:14:01 +00001174- mailbox.py now has a new class, PortableUnixMailbox which is
1175 identical to UnixMailbox but uses a more portable scheme for
1176 determining From_ separators. Also, the constructors for all the
1177 classes in this module have a new optional `factory' argument, which
1178 is a callable used when new message classes must be instantiated by
1179 the next() method.
1180
Tim Petersd7b5e882001-01-25 03:36:26 +00001181- random.py is now self-contained, and offers all the functionality of
1182 the now-deprecated whrandom.py. See the docs for details. random.py
1183 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001184 and restoring the internal state of the generator; and jumpahead(n),
1185 for quickly forcing the internal state to be the same as if n calls to
1186 random() had been made. The latter is particularly useful for multi-
1187 threaded programs, creating one instance of the random.Random() class for
1188 each thread, then using .jumpahead() to force each instance to use a
1189 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001190
Tim Peters0de88fc2001-02-01 04:59:18 +00001191- random.py's seed() function is new. For bit-for-bit compatibility with
1192 prior releases, use the whseed function instead. The new seed function
1193 addresses two problems: (1) The old function couldn't produce more than
1194 about 2**24 distinct internal states; the new one about 2**45 (the best
1195 that can be done in the Wichmann-Hill generator). (2) The old function
1196 sometimes produced identical internal states when passed distinct
1197 integers, and there was no simple way to predict when that would happen;
1198 the new one guarantees to produce distinct internal states for all
1199 arguments in [0, 27814431486576L).
1200
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001201- The socket module now supports raw packets on Linux. The socket
1202 family is AF_PACKET.
1203
Tim Peters9ea17ac2001-02-02 05:57:15 +00001204- test_capi.py is a start at running tests of the Python C API. The tests
1205 are implemented by the new Modules/_testmodule.c.
1206
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001207- A new extension module, _symtable, provides provisional access to the
1208 internal symbol table used by the Python compiler. A higher-level
1209 interface will be added on top of _symtable in a future release.
1210
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001211- Removed the obsolete soundex module.
1212
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001213- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1214 the isSameNode method; NamedNodeMap the get method.
1215
1216- xml.sax.expatreader supports the lexical handler property; it
1217 generates comment, startCDATA, and endCDATA events.
1218
Tim Petersee826f82001-01-31 19:39:44 +00001219Windows changes
1220
1221- Build procedure: the zlib project is built in a different way that
1222 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001223 the zlib binary used. See PCbuild\readme.txt for details. Your old
1224 zlib-related directories can be deleted; you'll need to download fresh
1225 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001226
Tim Peters9ea17ac2001-02-02 05:57:15 +00001227- Build: New subproject _test for the benefit of test_capi.py (see above).
1228
Tim Petersb16c56f2001-02-02 21:24:51 +00001229- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1230 interface to some Python compiler internals).
1231
1232- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001233 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001234
Tim Petersa3a3a032000-11-30 05:22:44 +00001235What's New in Python 2.1 alpha 1?
1236=================================
1237
1238Core language, builtins, and interpreter
1239
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001240- There is a new Unicode companion to the PyObject_Str() API
1241 called PyObject_Unicode(). It behaves in the same way as the
1242 former, but assures that the returned value is an Unicode object
1243 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001244
Guido van Rossumf98eda02001-01-17 15:54:45 +00001245- The comparison operators support "rich comparison overloading" (PEP
1246 207). C extension types can provide a rich comparison function in
1247 the new tp_richcompare slot in the type object. The cmp() function
1248 and the C function PyObject_Compare() first try the new rich
1249 comparison operators before trying the old 3-way comparison. There
1250 is also a new C API PyObject_RichCompare() (which also falls back on
1251 the old 3-way comparison, but does not constrain the outcome of the
1252 rich comparison to a Boolean result).
1253
1254 The rich comparison function takes two objects (at least one of
1255 which is guaranteed to have the type that provided the function) and
1256 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
1257 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
1258 object, which may be NotImplemented (in which case the tp_compare
1259 slot function is used as a fallback, if defined).
1260
1261 Classes can overload individual comparison operators by defining one
1262 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00001263 __ge__. There are no explicit "reflected argument" versions of
1264 these; instead, __lt__ and __gt__ are each other's reflection,
1265 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
1266 reflection (similar at the C level). No other implications are
1267 made; in particular, Python does not assume that == is the Boolean
1268 inverse of !=, or that < is the Boolean inverse of >=. This makes
1269 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00001270
1271 Classes or types that want to implement (in)equality tests but not
1272 the ordering operators (i.e. unordered types) should implement ==
1273 and !=, and raise an error for the ordering operators.
1274
Guido van Rossuma88479f2001-01-18 14:28:08 +00001275 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00001276 Boolean; e.g. a matrix type might want to return a matrix of bits
1277 for A < B, giving elementwise comparisons. Such types should ensure
1278 that any interpretation of their value in a Boolean context raises
1279 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
1280 at the C level) to always raise an exception.
1281
Guido van Rossuma88479f2001-01-18 14:28:08 +00001282- Complex numbers use rich comparisons to define == and != but raise
1283 an exception for <, <=, > and >=. Unfortunately, this also means
1284 that cmp() of two complex numbers raises an exception when the two
1285 numbers differ. Since it is not mathematically meaningful to compare
1286 complex numbers except for equality, I hope that this doesn't break
1287 too much code.
1288
Tim Peters3389f192001-02-18 08:48:49 +00001289- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00001290 not defined by the language, other than that it's arbitrary but
1291 consistent (see the Reference Manual). An implementation detail changed
1292 in 2.1a1 such that None now compares less than any other object. Code
1293 relying on this new behavior (like code that relied on the previous
1294 behavior) does so at its own risk.
1295
Barry Warsaw573b5412001-01-15 20:43:18 +00001296- Functions and methods now support getting and setting arbitrarily
1297 named attributes (PEP 232). Functions have a new __dict__
1298 (a.k.a. func_dict) which hold the function attributes. Methods get
1299 and set attributes on their underlying im_func. It is a TypeError
1300 to set an attribute on a bound method.
1301
Guido van Rossum051e3352001-01-15 19:11:10 +00001302- The xrange() object implementation has been improved so that
1303 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
1304 limitation that in this case len(xrange(sys.maxint)) can't be
1305 calculated, but the common idiom "for i in xrange(sys.maxint)" will
1306 work fine as long as the index i doesn't actually reach 2**31.
1307 (Python uses regular ints for sequence and string indices; fixing
1308 that is much more work.)
1309
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001310- Two changes to from...import:
1311
Guido van Rossumba381232001-02-03 15:06:40 +00001312 1) "from M import X" now works even if (after loading module M)
1313 sys.modules['M'] is not a real module; it's basically a getattr()
1314 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00001315
1316 2) "from M import *" now looks for M.__all__ to decide which names to
1317 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
1318 filters out names starting with '_' as before. Whether or not
1319 __all__ exists, there's no restriction on the type of M.
1320
Guido van Rossumf61f1662001-01-10 20:13:55 +00001321- File objects have a new method, xreadlines(). This is the fastest
1322 way to iterate over all lines in a file:
1323
1324 for line in file.xreadlines():
1325 ...do something to line...
1326
1327 See the xreadlines module (mentioned below) for how to do this for
1328 other file-like objects.
1329
1330- Even if you don't use file.xreadlines(), you may expect a speedup on
1331 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00001332 quite a bit in platform-specific ways: on systems (like Linux) that
1333 support flockfile(), getc_unlocked(), and funlockfile(), those are
1334 used by default. On systems (like Windows) without getc_unlocked(),
1335 a complicated (but still thread-safe) method using fgets() is used by
1336 default.
1337
Tim Petersd52269b2001-01-25 06:23:18 +00001338 You can force use of the fgets() method by #define'ing
1339 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00001340 getc_unlocked()).
1341
Tim Petersd52269b2001-01-25 06:23:18 +00001342 You can force fgets() not to be used by #define'ing
1343 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00001344 test_bufio.py fails -- and let us know if it does!).
1345
1346- In addition, the fileinput module, while still slower than the other
1347 methods on most platforms, has been sped up too, by using
1348 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001349
1350- Support for run-time warnings has been added, including a new
1351 command line option (-W) to specify the disposition of warnings.
1352 See the description of the warnings module below.
1353
1354- Extensive changes have been made to the coercion code. This mostly
1355 affects extension modules (which can now implement mixed-type
1356 numerical operators without having to use coercion), but
1357 occasionally, in boundary cases the coercion semantics have changed
1358 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00001359 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00001360 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00001361 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00001362
Guido van Rossumf98eda02001-01-17 15:54:45 +00001363- In connection with the coercion changes, a new built-in singleton
1364 object, NotImplemented is defined. This can be returned for
1365 operations that wish to indicate they are not implemented for a
1366 particular combination of arguments. From C, this is
1367 Py_NotImplemented.
1368
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001369- The interpreter accepts now bytecode files on the command line even
1370 if they do not have a .pyc or .pyo extension. On Linux, after executing
1371
Martin v. Löwise214baa2001-02-04 22:37:56 +00001372import imp,sys,string
1373magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
1374reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
1375open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00001376
1377 any byte code file can be used as an executable (i.e. as an argument
1378 to execve(2)).
1379
Tim Peters9940b802000-12-01 07:59:35 +00001380- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00001381 character. In 1.6 and earlier, they never produced a sign,
1382 and raised an error if the value of the long was too large
1383 to fit in a Python int. In 2.0, they produced a sign if and
1384 only if too large to fit in an int. This was inconsistent
1385 across platforms (because the size of an int varies across
1386 platforms), and inconsistent with hex() and oct(). Example:
1387
1388 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00001389 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00001390 'ffffffbe' # in 2.0 and before, on 32-bit machines
1391 >>> hex(-0x42L)
1392 '-0x42L' # in all versions of Python
1393
Tim Peters9940b802000-12-01 07:59:35 +00001394 The behavior of %d formats for negative Python longs remains
1395 the same as in 2.0 (although in 1.6 and before, they raised
1396 an error if the long didn't fit in a Python int).
1397
1398 %u formats don't make sense for Python longs, but are allowed
1399 and treated the same as %d in 2.1. In 2.0, a negative long
1400 formatted via %u produced a sign if and only if too large to
1401 fit in an int. In 1.6 and earlier, a negative long formatted
1402 via %u raised an error if it was too big to fit in an int.
1403
Guido van Rossum3661d392000-12-12 22:10:31 +00001404- Dictionary objects have an odd new method, popitem(). This removes
1405 an arbitrary item from the dictionary and returns it (in the form of
1406 a (key, value) pair). This can be useful for algorithms that use a
1407 dictionary as a bag of "to do" items and repeatedly need to pick one
1408 item. Such algorithms normally end up running in quadratic time;
1409 using popitem() they can usually be made to run in linear time.
1410
Tim Peters36cdad12000-12-29 02:06:45 +00001411Standard library
1412
Thomas Woutersfe385252001-01-19 23:16:56 +00001413- In the time module, the time argument to the functions strftime,
1414 localtime, gmtime, asctime and ctime is now optional, defaulting to
1415 the current time (in the local timezone).
1416
Guido van Rossumda91f222001-01-15 16:36:08 +00001417- The ftplib module now defaults to passive mode, which is deemed a
1418 more useful default given that clients are often inside firewalls
1419 these days. Note that this could break if ftplib is used to connect
1420 to a *server* that is inside a firewall, from outside; this is
1421 expected to be a very rare situation. To fix that, you can call
1422 ftp.set_pasv(0).
1423
Martin v. Löwis10a27872001-01-13 09:54:41 +00001424- The module site now treats .pth files not only for path configuration,
1425 but also supports extensions to the initialization code: Lines starting
1426 with import are executed.
1427
Guido van Rossumf61f1662001-01-10 20:13:55 +00001428- There's a new module, warnings, which implements a mechanism for
1429 issuing and filtering warnings. There are some new built-in
1430 exceptions that serve as warning categories, and a new command line
1431 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
1432 turns warnings into errors). warnings.warn(message[, category])
1433 issues a warning message; this can also be called from C as
1434 PyErr_Warn(category, message).
1435
1436- A new module xreadlines was added. This exports a single factory
1437 function, xreadlines(). The intention is that this code is the
1438 absolutely fastest way to iterate over all lines in an open
1439 file(-like) object:
1440
1441 import xreadlines
1442 for line in xreadlines.xreadlines(file):
1443 ...do something to line...
1444
1445 This is equivalent to the previous the speed record holder using
1446 file.readlines(sizehint). Note that if file is a real file object
1447 (as opposed to a file-like object), this is equivalent:
1448
1449 for line in file.xreadlines():
1450 ...do something to line...
1451
Tim Peters36cdad12000-12-29 02:06:45 +00001452- The bisect module has new functions bisect_left, insort_left,
1453 bisect_right and insort_right. The old names bisect and insort
1454 are now aliases for bisect_right and insort_right. XXX_right
1455 and XXX_left methods differ in what happens when the new element
1456 compares equal to one or more elements already in the list: the
1457 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00001458 right. Code that doesn't care where equal elements end up should
1459 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00001460
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00001461- The new curses.panel module wraps the panel library that forms part
1462 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
1463
Guido van Rossumf61f1662001-01-10 20:13:55 +00001464- The SocketServer module now sets the allow_reuse_address flag by
1465 default in the TCPServer class.
1466
1467- A new function, sys._getframe(), returns the stack frame pointer of
1468 the caller. This is intended only as a building block for
1469 higher-level mechanisms such as string interpolation.
1470
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001471- The pyexpat module supports a number of new handlers, which are
1472 available only in expat 1.2. If invocation of a callback fails, it
1473 will report an additional frame in the traceback. Parser objects
1474 participate now in garbage collection. If expat reports an unknown
1475 encoding, pyexpat will try to use a Python codec; that works only
1476 for single-byte charsets. The parser type objects is exposed as
1477 XMLParserObject.
1478
1479- xml.dom now offers standard definitions for symbolic node type and
1480 exception code constants, and a hierarchy of DOM exceptions. minidom
1481 was adjusted to use them.
1482
1483- The conformance of xml.dom.minidom to the DOM specification was
1484 improved. It detects a number of additional error cases; the
1485 previous/next relationship works even when the tree is modified;
1486 Node supports the normalize() method; NamedNodeMap, DocumentType and
1487 DOMImplementation classes were added; Element supports the
1488 hasAttribute and hasAttributeNS methods; and Text supports the splitText
1489 method.
1490
Guido van Rossumf61f1662001-01-10 20:13:55 +00001491Build issues
1492
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00001493- For Unix (and Unix-compatible) builds, configuration and building of
1494 extension modules is now greatly automated. Rather than having to
1495 edit the Modules/Setup file to indicate which modules should be
1496 built and where their include files and libraries are, a
1497 distutils-based setup.py script now takes care of building most
1498 extension modules. All extension modules built this way are built
1499 as shared libraries. Only a few modules that must be linked
1500 statically are still listed in the Setup file; you won't need to
1501 edit their configuration.
1502
1503- Python should now build out of the box on Cygwin. If it doesn't,
1504 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00001505
1506- Python now always uses its own (renamed) implementation of getopt()
1507 -- there's too much variation among C library getopt()
1508 implementations.
1509
1510- C++ compilers are better supported; the CXX macro is always set to a
1511 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00001512
Tim Petersd92dfe02000-12-12 01:18:41 +00001513Windows changes
1514
1515- select module: By default under Windows, a select() call
1516 can specify no more than 64 sockets. Python now boosts
1517 this Microsoft default to 512. If you need even more than
1518 that, see the MS docs (you'll need to #define FD_SETSIZE
1519 and recompile Python from source).
1520
Guido van Rossumf61f1662001-01-10 20:13:55 +00001521- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
1522 subdirectory is no more!
1523
Tim Petersa3a3a032000-11-30 05:22:44 +00001524
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001525What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00001526=========================
Guido van Rossum61000331997-08-15 04:39:58 +00001527
Guido van Rossum8ed602b2000-09-01 22:34:33 +00001528Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001529changes are in the file HISTORY. If you are making the jump directly
1530from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
1531HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00001532
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001533Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
1534the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
1535http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00001536
Guido van Rossumf2ffce02000-09-05 04:38:34 +00001537--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00001538
1539======================================================================
1540
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001541What's new in 2.0 (since release candidate 1)?
1542==============================================
1543
1544Standard library
1545
1546- The copy_reg module was modified to clarify its intended use: to
1547 register pickle support for extension types, not for classes.
1548 pickle() will raise a TypeError if it is passed a class.
1549
1550- Fixed a bug in gettext's "normalize and expand" code that prevented
1551 it from finding an existing .mo file.
1552
1553- Restored support for HTTP/0.9 servers in httplib.
1554
Tim Peters989b7b92000-10-16 20:24:53 +00001555- The math module was changed to stop raising OverflowError in case of
1556 underflow, and return 0 instead in underflow cases. Whether Python
1557 used to raise OverflowError in case of underflow was platform-
1558 dependent (it did when the platform math library set errno to ERANGE
1559 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001560
1561- Fixed a bug in StringIO that occurred when the file position was not
1562 at the end of the file and write() was called with enough data to
1563 extend past the end of the file.
1564
1565- Fixed a bug that caused Tkinter error messages to get lost on
1566 Windows. The bug was fixed by replacing direct use of
1567 interp->result with Tcl_GetStringResult(interp).
1568
1569- Fixed bug in urllib2 that caused it to fail when it received an HTTP
1570 redirect response.
1571
1572- Several changes were made to distutils: Some debugging code was
1573 removed from util. Fixed the installer used when an external zip
1574 program (like WinZip) is not found; the source code for this
1575 installer is in Misc/distutils. check_lib() was modified to behave
1576 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
1577 test for whether installed modules are on sys.path was changed to
1578 use both normcase() and normpath().
1579
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00001580- Several minor bugs were fixed in the xml package (the minidom,
1581 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001582
1583- The regression test driver (regrtest.py) behavior when invoked with
1584 -l changed: It now reports a count of objects that are recognized as
1585 garbage but not freed by the garbage collector.
1586
Tim Peters989b7b92000-10-16 20:24:53 +00001587- The regression test for the math module was changed to test
1588 exceptional behavior when the test is run in verbose mode. Python
1589 cannot yet guarantee consistent exception behavior across platforms,
1590 so the exception part of test_math is run only in verbose mode, and
1591 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001592
1593Internals
1594
1595- PyOS_CheckStack() has been disabled on Win64, where it caused
1596 test_sre to fail.
1597
1598Build issues
1599
1600- Changed compiler flags, so that gcc is always invoked with -Wall and
1601 -Wstrict-prototypes. Users compiling Python with GCC should see
1602 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00001603 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00001604 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001605
Tim Petersa3a3a032000-11-30 05:22:44 +00001606- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001607
1608Tools and other miscellany
1609
1610- The compiler in Tools/compiler was updated to support the new
1611 language features introduced in 2.0: extended print statement, list
1612 comprehensions, and augmented assignments. The new compiler should
1613 also be backwards compatible with Python 1.5.2; the compiler will
1614 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00001615 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001616
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001617What's new in 2.0 release candidate 1 (since beta 2)?
1618=====================================================
1619
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00001620What is release candidate 1?
1621
1622We believe that release candidate 1 will fix all known bugs that we
1623intend to fix for the 2.0 final release. This release should be a bit
1624more stable than the previous betas. We would like to see even more
1625widespread testing before the final release, so we are producing this
1626release candidate. The final release will be exactly the same unless
1627any show-stopping (or brown bag) bugs are found by testers of the
1628release candidate.
1629
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001630All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001631to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001632
1633Core language, builtins, and interpreter
1634
1635- A bug that caused crashes when __coerce__ was used with augmented
1636 assignment, e.g. +=, was fixed.
1637
1638- Raise ZeroDivisionError when raising zero to a negative number,
1639 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
1640 power operator and the result of math.pow(0.0, -2.0) will vary by
1641 platform. On Linux, it raises a ValueError.
1642
1643- A bug in Unicode string interpolation was fixed that occasionally
1644 caused errors with formats including "%%". For example, the
1645 following expression "%% %s" % u"abc" no longer raises a TypeError.
1646
1647- Compilation of deeply nested expressions raises MemoryError instead
1648 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
1649
1650- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
1651 rendering them useless. They are now written in binary mode again.
1652
1653Standard library
1654
1655- Keyword arguments are now accepted for most pattern and match object
1656 methods in SRE, the standard regular expression engine.
1657
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001658- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00001659 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001660
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001661- Several bugs in the Unicode handling and error handling in _tkinter
1662 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001663
1664- Fix memory management errors in Merge() and Tkapp_Call() routines.
1665
1666- Several changes were made to cStringIO to make it compatible with
1667 the file-like object interface and with StringIO. If operations are
1668 performed on a closed object, an exception is raised. The truncate
1669 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00001670 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001671
1672- There were many changes made to the linuxaudiodev module and its
1673 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00001674 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001675
1676 Note that this module is named poorly, because it should work
1677 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00001678 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001679
1680 The module now raises exceptions when errors occur instead of
1681 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
1682 audio) and defines a getptr() method that calls the
1683 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
1684
1685- The library_version attribute, introduced in an earlier beta, was
1686 removed because it can not be supported with early versions of the C
1687 readline library, which provides no way to determine the version at
1688 compile-time.
1689
1690- The binascii module is now enabled on Win64.
1691
Tim Peters46446d62000-10-09 21:19:31 +00001692- tokenize.py no longer suffers "recursion depth" errors when parsing
1693 programs with very long string literals.
1694
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001695Internals
1696
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001697- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001698 which is called when the interpreter starts up to determine where
1699 the standard library is installed. These vulnerabilities affect all
1700 previous versions of Python and can be exploited by setting very
1701 long values for PYTHONHOME or argv[0]. The risk is greatest for a
1702 setuid Python script, although use of the wrapper in
1703 Misc/setuid-prog.c will eliminate the vulnerability.
1704
1705- Fixed garbage collection bugs in instance creation that were
1706 triggered when errors occurred during initialization. The solution,
1707 applied in cPickle and in PyInstance_New(), is to call
1708 PyObject_GC_Init() after the initialization of the object's
1709 container attributes is complete.
1710
1711- pyexpat adds definitions of PyModule_AddStringConstant and
1712 PyModule_AddObject if the Python version is less than 2.0, which
1713 provides compatibility with PyXML on Python 1.5.2.
1714
1715- If the platform has a bogus definition for LONG_BIT (the number of
1716 bits in a long), an error will be reported at compile time.
1717
1718- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
1719 collection crashes and possibly other, unreported crashes.
1720
1721- Fixed a memory leak in _PyUnicode_Fini().
1722
1723Build issues
1724
1725- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001726 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00001727 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001728
1729- The mmap.PAGESIZE constant is now initialized using sysconf when
1730 possible, which eliminates a dependency on -lucb for Reliant UNIX.
1731
1732- The md5 file should now compile on all platforms.
1733
1734- The select module now compiles on platforms that do not define
1735 POLLRDNORM and related constants.
1736
1737- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00001738 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001739
Jeremy Hylton10921202000-10-09 18:34:12 +00001740- BeOS: A number of changes were made to the build and installation
1741 process. ar-fake now operates on a directory of object files.
1742 dl_export.h is gone, and its macros now appear on the mwcc command
1743 line during build on PPC BeOS.
1744
Jeremy Hyltond6e20232000-10-16 20:08:38 +00001745- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00001746 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00001747
1748- Cygwin: Support for shared libraries, Tkinter, and sockets.
1749
1750- SunOS 4.1.4_JL: Fix test for directory existence in configure.
1751
1752Tools and other miscellany
1753
1754- Removed debugging prints from main used with freeze.
1755
Tim Peters46446d62000-10-09 21:19:31 +00001756- IDLE auto-indent no longer crashes when it encounters Unicode
1757 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001758
1759What's new in 2.0 beta 2 (since beta 1)?
1760========================================
1761
1762Core language, builtins, and interpreter
1763
Tim Peters482c0212000-09-26 06:33:09 +00001764- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001765 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001766
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001767- Add -h and -V command line options to print the usage message and
1768 Python version number and exit immediately.
1769
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001770- eval() and exec accept Unicode objects as code parameters.
1771
1772- getattr() and setattr() now also accept Unicode objects for the
1773 attribute name, which are converted to strings using the default
1774 encoding before lookup.
1775
1776- Multiplication on string and Unicode now does proper bounds
1777 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
1778 string is too long."
1779
1780- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00001781 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001782
Jeremy Hylton1b618592000-09-26 05:32:36 +00001783
1784Standard library and extensions
1785
Guido van Rossum5b08f132001-04-16 02:05:23 +00001786- socket module: the OpenSSL code now adds support for RAND_status()
1787 and EGD (Entropy Gathering Device).
1788
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001789- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00001790 argument checking; it still takes no arguments.
1791
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001792- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001793
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001794- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001795
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001796- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001797
1798- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001799 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001800
1801- copy: Copy Unicode objects atomically.
1802
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001803- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001804
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001805- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001806
Fred Drake67233bc2000-09-26 16:40:27 +00001807- dbm: Add get() and setdefault() methods to dbm object. Add constant
1808 `library' to module that names the library used. Added doc strings
1809 and method names to error messages. Uses configure to determine
1810 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
1811 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001812
1813- distutils: Update to version 0.9.3.
1814
1815- dl: Add several dl.RTLD_ constants.
1816
1817- fpectl: Now supported on FreeBSD.
1818
1819- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
1820 found by the collector will be saved in gc.garbage. This is useful
1821 for debugging a program that creates reference cycles.
1822
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001823- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00001824 of HTTP class. Do not close socket on zero-length response. Do not
1825 crash when server sends invalid content-length header.
1826
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001827- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001828
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001829- marshal: When reading a short, sign-extend on platforms where shorts
1830 are bigger than 16 bits. When reading a long, repair the unportable
1831 sign extension that was being done for 64-bit machines. (It assumed
1832 that signed right shift sign-extends.)
1833
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001834- operator: Add contains(), invert(), __invert__() as aliases for
1835 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001836
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001837- os: Add support for popen2() and popen3() on all platforms where
1838 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001839
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001840- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00001841 clicking on a file in Explorer (or passing the file name to the
1842 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001843
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001844- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00001845 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00001846
1847- pickle: Now raises ValueError when an invalid pickle that contains
1848 a non-string repr where a string repr was expected. This behavior
1849 matches cPickle.
1850
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001851- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001852
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001853- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001854
1855- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001856 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001857 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00001858
1859- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001860 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001861
1862- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00001863 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00001864 few cycles during startup since the first call to
1865 setdefaultencoding() will initialize the codec registry and the
1866 encodings package.
1867
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001868- socket: Support for size hint in readlines() method of object returned
1869 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001870
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001871- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00001872 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00001873 is followed by whitespace.
1874
Tim Petersa3a3a032000-11-30 05:22:44 +00001875- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001876
1877- struct: Check ranges for bytes and shorts.
1878
1879- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001880 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001881
1882- Tkinter: Image objects are now guaranteed to have unique ids. Set
1883 event.delta to zero if Tk version doesn't support mousewheel.
1884 Removed some debugging prints.
1885
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001886- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00001887
Fred Drake67233bc2000-09-26 16:40:27 +00001888- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001889 which works around a bug in Norton AntiVirus 2000 that leads directly
1890 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001891
1892- xml: New version detection code allows PyXML to override standard
1893 XML package if PyXML version is greater than 0.6.1.
1894
Fred Drake64bb3802000-09-26 16:21:35 +00001895- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
1896 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
1897 tree only for nodes which are sufficiently interesting to a specific
1898 application. Does not provide the HTML-specific extensions. Still
1899 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001900
Fred Drake64bb3802000-09-26 16:21:35 +00001901- xml.sax: SAX 2 support for Python, including all the handler
1902 interfaces needed to process XML 1.0 compliant XML. Some
1903 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001904
Fred Drake64bb3802000-09-26 16:21:35 +00001905- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
1906 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001907
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001908
Jeremy Hylton1b618592000-09-26 05:32:36 +00001909C API
1910
1911- Add three new convenience functions for module initialization --
1912 PyModule_AddObject(), PyModule_AddIntConstant(), and
1913 PyModule_AddStringConstant().
1914
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001915- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00001916 removed and add #error to Python.h if NULL isn't defined after
1917 #include of stdio.h.
1918
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001919- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00001920 backwards compatibility (at the source level) with old extensions.
1921
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001922- A wrapper API was added for signal() and sigaction(). Instead of
1923 either function, always use PyOS_getsig() to get a signal handler
1924 and PyOS_setsig() to set one. A new convenience typedef
1925 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001926
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001927- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00001928 internal data buffer and size of a string object -- or the default
1929 encoded version of a Unicode object.
1930
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001931- PyString_Size() and PyString_AsString() accept Unicode objects.
1932
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001933- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00001934 exists). INT_MAX and LONG_MAX will always be defined, even if
1935 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001936
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001937- PyFloat_FromString takes a second argument, pend, that was
1938 effectively useless. It is now officially useless but preserved for
1939 backwards compatibility. If the pend argument is not NULL, *pend is
1940 set to NULL.
1941
1942- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
1943 for the attribute name. See note on getattr() above.
1944
1945- A few bug fixes to argument processing for Unicode.
1946 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
1947 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
1948 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00001949 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001950
1951- Py_BuildValue accepts B format (for bgen-generated code).
1952
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001953
Jeremy Hylton1b618592000-09-26 05:32:36 +00001954Internals
1955
1956- On Unix, fix code for finding Python installation directory so that
1957 it works when argv[0] is a relative path.
1958
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00001959- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001960 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00001961 rather than by generating a copy of the object.
1962
Tim Peters482c0212000-09-26 06:33:09 +00001963- Several of the internal Unicode tables are much smaller now, and
1964 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001965
Jeremy Hylton97693b02000-09-26 17:42:51 +00001966- In the garbage collector: Fixed bug in collection of tuples. Fixed
1967 bug that caused some instances to be removed from the container set
1968 while they were still live. Fixed parsing in gc.set_debug() for
1969 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001970
1971- Fixed refcount problem in instance deallocation that only occurred
1972 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
1973
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001974- On Windows, getpythonregpath is now protected against null data in
1975 registry key.
1976
1977- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00001978 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001979
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001980
Jeremy Hylton1b618592000-09-26 05:32:36 +00001981Build and platform-specific issues
1982
1983- Better support of GNU Pth via --with-pth configure option.
1984
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001985- Python/C API now properly exposed to dynamically-loaded extension
1986 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00001987
1988- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
1989 Don't define MS_SYNC to be zero when it is undefined. Added missing
1990 prototypes in posixmodule.c.
1991
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001992- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00001993 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00001994
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00001995- Fix largefile support on older NetBSD systems and OpenBSD by adding
1996 define for TELL64.
1997
1998
1999Tools and other miscellany
2000
2001- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2002
2003- freeze: The modulefinder now works with 2.0 opcodes.
2004
Tim Petersa3a3a032000-11-30 05:22:44 +00002005- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002006 Move hackery of sys.argv until after the Tk instance has been
2007 created, which allows the application-specific Tkinter
2008 initialization to be executed if present; also pass an explicit
2009 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002010
Jeremy Hylton1b618592000-09-26 05:32:36 +00002011
2012What's new in 2.0 beta 1?
2013=========================
2014
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002015Source Incompatibilities
2016------------------------
2017
2018None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2019such as single-argument append(), connect() and bind(), and changes to
2020str(long) and repr(float).
2021
2022
2023Binary Incompatibilities
2024------------------------
2025
2026- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2027with Python 2.0; these extensions will have to be rebuilt for Python
20282.0.
2029
2030- On Windows, attempting to import a third party extension built for
2031Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2032can do about this. Check your PYTHONPATH environment variable!
2033
2034- Python bytecode files (*.pyc and *.pyo) are not compatible between
2035releases.
2036
2037
2038Overview of Changes Since 1.6
2039-----------------------------
2040
2041There are many new modules (including brand new XML support through
2042the xml package, and i18n support through the gettext module); a list
2043of all new modules is included below. Lots of bugs have been fixed.
2044
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002045The process for making major new changes to the language has changed
2046since Python 1.6. Enhancements must now be documented by a Python
2047Enhancement Proposal (PEP) before they can be accepted.
2048
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002049There are several important syntax enhancements, described in more
2050detail below:
2051
2052 - Augmented assignment, e.g. x += 1
2053
2054 - List comprehensions, e.g. [x**2 for x in range(10)]
2055
2056 - Extended import statement, e.g. import Module as Name
2057
2058 - Extended print statement, e.g. print >> file, "Hello"
2059
2060Other important changes:
2061
2062 - Optional collection of cyclical garbage
2063
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002064Python Enhancement Proposal (PEP)
2065---------------------------------
2066
2067PEP stands for Python Enhancement Proposal. A PEP is a design
2068document providing information to the Python community, or describing
2069a new feature for Python. The PEP should provide a concise technical
2070specification of the feature and a rationale for the feature.
2071
2072We intend PEPs to be the primary mechanisms for proposing new
2073features, for collecting community input on an issue, and for
2074documenting the design decisions that have gone into Python. The PEP
2075author is responsible for building consensus within the community and
2076documenting dissenting opinions.
2077
2078The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002079
2080Augmented Assignment
2081--------------------
2082
2083This must have been the most-requested feature of the past years!
2084Eleven new assignment operators were added:
2085
Guido van Rossume905e952000-09-05 12:42:46 +00002086 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002087
2088For example,
2089
2090 A += B
2091
2092is similar to
2093
2094 A = A + B
2095
2096except that A is evaluated only once (relevant when A is something
2097like dict[index].attr).
2098
2099However, if A is a mutable object, A may be modified in place. Thus,
2100if A is a number or a string, A += B has the same effect as A = A+B
2101(except A is only evaluated once); but if a is a list, A += B has the
2102same effect as A.extend(B)!
2103
2104Classes and built-in object types can override the new operators in
2105order to implement the in-place behavior; the not-in-place behavior is
2106used automatically as a fallback when an object doesn't implement the
2107in-place behavior. For classes, the method name is derived from the
2108method name for the corresponding not-in-place operator by inserting
2109an 'i' in front of the name, e.g. __iadd__ implements in-place
2110__add__.
2111
2112Augmented assignment was implemented by Thomas Wouters.
2113
2114
2115List Comprehensions
2116-------------------
2117
2118This is a flexible new notation for lists whose elements are computed
2119from another list (or lists). The simplest form is:
2120
2121 [<expression> for <variable> in <sequence>]
2122
Guido van Rossum56db0952000-09-06 23:34:25 +00002123For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002124This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002125
2126You can also add a condition:
2127
2128 [<expression> for <variable> in <sequence> if <condition>]
2129
2130For example, [w for w in words if w == w.lower()] would yield the list
2131of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002132than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002133
2134You can also have nested for loops and more than one 'if' clause. For
2135example, here's a function that flattens a sequence of sequences::
2136
2137 def flatten(seq):
2138 return [x for subseq in seq for x in subseq]
2139
2140 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2141
2142This prints
2143
2144 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2145
2146List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002147Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002148
2149
2150Extended Import Statement
2151-------------------------
2152
2153Many people have asked for a way to import a module under a different
2154name. This can be accomplished like this:
2155
2156 import foo
2157 bar = foo
2158 del foo
2159
2160but this common idiom gets old quickly. A simple extension of the
2161import statement now allows this to be written as follows:
2162
2163 import foo as bar
2164
2165There's also a variant for 'from ... import':
2166
2167 from foo import bar as spam
2168
2169This also works with packages; e.g. you can write this:
2170
2171 import test.regrtest as regrtest
2172
2173Note that 'as' is not a new keyword -- it is recognized only in this
2174context (this is only possible because the syntax for the import
2175statement doesn't involve expressions).
2176
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002177Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002178
2179
2180Extended Print Statement
2181------------------------
2182
2183Easily the most controversial new feature, this extension to the print
2184statement adds an option to make the output go to a different file
2185than the default sys.stdout.
2186
2187For example, to write an error message to sys.stderr, you can now
2188write:
2189
2190 print >> sys.stderr, "Error: bad dog!"
2191
2192As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002193evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002194
2195 print >> None, "Hello world"
2196
2197is equivalent to
2198
2199 print "Hello world"
2200
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002201Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002202
2203
2204Optional Collection of Cyclical Garbage
2205---------------------------------------
2206
2207Python is now equipped with a garbage collector that can hunt down
2208cyclical references between Python objects. It's no replacement for
2209reference counting; in fact, it depends on the reference counts being
2210correct, and decides that a set of objects belong to a cycle if all
2211their reference counts can be accounted for from their references to
2212each other. This devious scheme was first proposed by Eric Tiedemann,
2213and brought to implementation by Neil Schemenauer.
2214
2215There's a module "gc" that lets you control some parameters of the
2216garbage collection. There's also an option to the configure script
2217that lets you enable or disable the garbage collection. In 2.0b1,
2218it's on by default, so that we (hopefully) can collect decent user
2219experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002220performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002221off by default in the final 2.0 release.
2222
2223
2224Smaller Changes
2225---------------
2226
2227A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2228map(None, seq1, seq2, ...) when the sequences have the same length;
2229i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2230the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002231zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002232
2233sys.version_info is a tuple (major, minor, micro, level, serial).
2234
2235Dictionaries have an odd new method, setdefault(key, default).
2236dict.setdefault(key, default) returns dict[key] if it exists; if not,
2237it sets dict[key] to default and returns that value. Thus:
2238
2239 dict.setdefault(key, []).append(item)
2240
2241does the same work as this common idiom:
2242
2243 if not dict.has_key(key):
2244 dict[key] = []
2245 dict[key].append(item)
2246
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002247There are two new variants of SyntaxError that are raised for
2248indentation-related errors: IndentationError and TabError.
2249
2250Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2251escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002252
2253The limits on the size of expressions and file in Python source code
2254have been raised from 2**16 to 2**32. Previous versions of Python
2255were limited because the maximum argument size the Python VM accepted
2256was 2**16. This limited the size of object constructor expressions,
2257e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
2258limit was raised thanks to a patch by Charles Waldman that effectively
2259fixes the problem. It is now much more likely that you will be
2260limited by available memory than by an arbitrary limit in Python.
2261
2262The interpreter's maximum recursion depth can be modified by Python
2263programs using sys.getrecursionlimit and sys.setrecursionlimit. This
2264limit is the maximum number of recursive calls that can be made by
2265Python code. The limit exists to prevent infinite recursion from
2266overflowing the C stack and causing a core dump. The default value is
22671000. The maximum safe value for a particular platform can be found
2268by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002269
2270New Modules and Packages
2271------------------------
2272
2273atexit - for registering functions to be called when Python exits.
2274
2275imputil - Greg Stein's alternative API for writing custom import
2276hooks.
2277
2278pyexpat - an interface to the Expat XML parser, contributed by Paul
2279Prescod.
2280
2281xml - a new package with XML support code organized (so far) in three
2282subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
2283would fill a volume. There's a special feature whereby a
2284user-installed package named _xmlplus overrides the standard
2285xmlpackage; this is intended to give the XML SIG a hook to distribute
2286backwards-compatible updates to the standard xml package.
2287
2288webbrowser - a platform-independent API to launch a web browser.
2289
2290
Guido van Rossume905e952000-09-05 12:42:46 +00002291Changed Modules
2292---------------
2293
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002294array -- new methods for array objects: count, extend, index, pop, and
2295remove
2296
2297binascii -- new functions b2a_hex and a2b_hex that convert between
2298binary data and its hex representation
2299
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002300calendar -- Many new functions that support features including control
2301over which day of the week is the first day, returning strings instead
2302of printing them. Also new symbolic constants for days of week,
2303e.g. MONDAY, ..., SUNDAY.
2304
2305cgi -- FieldStorage objects have a getvalue method that works like a
2306dictionary's get method and returns the value attribute of the object.
2307
2308ConfigParser -- The parser object has new methods has_option,
2309remove_section, remove_option, set, and write. They allow the module
2310to be used for writing config files as well as reading them.
2311
2312ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00002313optionally support the RFC 959 REST command.
2314
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002315gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00002316
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002317httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
2318the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00002319
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002320locale -- implement getdefaultlocale for Win32 and Macintosh
2321
2322marshal -- no longer dumps core when marshaling deeply nested or
2323recursive data structures
2324
2325os -- new functions isatty, seteuid, setegid, setreuid, setregid
2326
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002327os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
2328support under Unix.
2329
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002330os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002331
2332os.path -- fix semantics of os.path.commonprefix
2333
2334smtplib -- support for sending very long messages
2335
2336socket -- new function getfqdn()
2337
2338readline -- new functions to read, write and truncate history files.
2339The readline section of the library reference manual contains an
2340example.
2341
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002342select -- add interface to poll system call
2343
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002344shutil -- new copyfileobj function
2345
2346SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
2347HTTP server.
2348
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002349Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002350
2351urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00002352e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002353
2354whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00002355
2356
2357Obsolete Modules
2358----------------
2359
2360None. However note that 1.6 made a whole slew of modules obsolete:
2361stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
2362poly, zmod, strop, util, whatsound.
2363
2364
2365Changed, New, Obsolete Tools
2366----------------------------
2367
Tim Peters8b092332000-09-05 20:15:25 +00002368None.
Guido van Rossume905e952000-09-05 12:42:46 +00002369
2370
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002371C-level Changes
2372---------------
2373
2374Several cleanup jobs were carried out throughout the source code.
2375
2376All C code was converted to ANSI C; we got rid of all uses of the
2377Py_PROTO() macro, which makes the header files a lot more readable.
2378
2379Most of the portability hacks were moved to a new header file,
2380pyport.h; several other new header files were added and some old
2381header files were removed, in an attempt to create a more rational set
2382of header files. (Few of these ever need to be included explicitly;
2383they are all included by Python.h.)
2384
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002385Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002386and Win64, especially for the new Intel Itanium processor. Mick also
2387added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002388
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002389The C APIs to return an object's size have been update to consistently
2390use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
2391previous versions, the abstract interfaces used PyXXX_Length and the
2392concrete interfaces used PyXXX_Size. The old names,
2393e.g. PyObject_Length, are still available for backwards compatibility
2394at the API level, but are deprecated.
2395
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002396The PyOS_CheckStack function has been implemented on Windows by
2397Fredrik Lundh. It prevents Python from failing with a stack overflow
2398on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002399
2400The GC changes resulted in creation of two new slots on object,
2401tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00002402the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002403
2404The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00002405C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002406
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002407PyErr_Format has been updated to automatically calculate the size of
2408the buffer needed to hold the formatted result string. This change
2409prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002410
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002411New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00002412
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002413PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
2414that are the same as their non-Ex counterparts except they take an
2415extra flag argument that tells them to close the file when done.
2416
2417XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002418
Tim Peters8b092332000-09-05 20:15:25 +00002419
2420Windows Changes
2421---------------
2422
2423New popen2/popen3/peopen4 in os module (see Changed Modules above).
2424
2425os.popen is much more usable on Windows 95 and 98. See Microsoft
2426Knowledge Base article Q150956. The Win9x workaround described there
2427is implemented by the new w9xpopen.exe helper in the root of your
2428Python installation. Note that Python uses this internally; it is not
2429a standalone program.
2430
2431Administrator privileges are no longer required to install Python
2432on Windows NT or Windows 2000. If you have administrator privileges,
2433Python's registry info will be written under HKEY_LOCAL_MACHINE.
2434Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00002435under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00002436uses of Python, but will prevent some advanced uses from working
2437(for example, running a Python script as an NT service, or possibly
2438from CGI).
2439
2440[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
2441installer; instead, it installs the needed Tcl/Tk files directly in the
2442Python directory. If you already have a Tcl/Tk installation, this
2443wastes some disk space (about 4 Megs) but avoids problems with
2444conflicting Tcl/Tk installations, and makes it much easier for Python
2445to ensure that Tcl/Tk can find all its files.
2446
2447[This was new in 1.6] The Windows installer now installs by default in
2448\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
2449
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002450
2451Updates to the changes between 1.5.2 and 1.6
2452--------------------------------------------
2453
2454The 1.6 NEWS file can't be changed after the release is done, so here
2455is some late-breaking news:
2456
2457New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
2458and changes to getlocale() and setlocale().
2459
2460The new module is now enabled per default.
2461
2462It is not true that the encodings codecs cannot be used for normal
2463strings: the string.encode() (which is also present on 8-bit strings
2464!) allows using them for 8-bit strings too, e.g. to convert files from
2465cp1252 (Windows) to latin-1 or vice-versa.
2466
2467Japanese codecs are available from Tamito KAJIYAMA:
2468http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
2469
2470
Guido van Rossumab9d6f01998-08-10 22:01:13 +00002471======================================================================