Below is a partial list of changes. This list is much more detailed than
previous; however it is still not complete. I did go through my CVS logs
-but ran out of time. I believe that at least all major changes are
-actually noted here. Note that I have not placed
+but ran out of time. Some changes made beteen Oct 1996 and April 1997
+have not yet been noted.
Miscellaneous
-------------
-- The default module search path is now much saner. Both on Unix and
-Windows, it is essentially derived from the path to the executable which
-can be overridden by setting the environment variable $PYTHONHOME). The
-value of $PYTHONPATH on Windows is now inserted in front of the default
-path, like in Unix (instead of overriding the default path). On Windows,
-the directory containing the executable is added to the end of the path.
+- The default module search path is now much saner. Both on Unix and
+Windows, it is essentially derived from the path to the executable
+(which can be overridden by setting the environment variable
+$PYTHONHOME). The value of $PYTHONPATH on Windows is now inserted in
+front of the default path, like in Unix (instead of overriding the
+default path). On Windows, the directory containing the executable is
+added to the end of the path.
+
+- On Unix, when using sys.argv[0] to insert the script directory in
+front of sys.path, expand a symbolic link. You can now install a
+program in a private directory and have a symbolic link to it in a
+public bin directory, and it will put the private directory in the
+module search path. Note that the symlink is expanded in sys.path[0]
+but not in sys.argv[0], so you can still tell the name by which you
+were invoked.
+
+- It is now recommended to use ``#!/usr/bin/env python'' instead of
+``#!/usr/local/bin/python'' at the start of executable scripts, except
+for CGI scripts. It has been determined that the use of /usr/bin/env
+is more portable than that of /usr/local/bin/python -- scripts almost
+never have to be edited when the Python interpreter lives in a
+non-standard place. Note that this doesn't work for CGI scripts since
+the python executable often doesn't live in the HTTP server's default
+search path.
- The silly -s command line option and the corresponding
PYTHONSUPPRESS environment variable (and the Py_SuppressPrint global
The simplest example is ``def f((a,b),(c,d)): print a,b,c,d''; this
would print the wrong value when run under the debugger or profiler.
+- The sort() methods for lists no longer uses the C library qsort(); I
+wrote my own quicksort implementation, with help from Tim Peters.
+This solves a bug in dictionary comparisons on some Solaris versions
+when Python is built with threads, and makes sorting lists even
+faster.
+
+- The hacks that the dictionary implementation used to speed up
+repeated lookups of the same C string were removed; these were a
+source of subtle problems and don't seem to serve much of a purpose
+any longer.
+
+- All traces of support for the long dead access statement have been
+removed from the sources.
+
- Plugged the two-byte memory leak in the tokenizer when reading an
interactive EOF.
Performance
-----------
-- It's much faster (almost twice for pystone.py -- see Tools/scripts).
+- It's much faster (almost twice for pystone.py -- see
+Tools/scripts). See the entry on string interning below.
- Some speedup by using separate free lists for method objects (both
the C and the Python variety) and for floating point numbers.
- Small speedup by reordering the method tables of some common
objects (e.g. list.append is now first).
+- Big optimization to the read() method of file objects. A read()
+without arguments now attempts to use fstat to allocate a buffer of
+the right size; for pipes and sockets, it will fall back to doubling
+the buffer size. While that the improvement is real on all systems,
+it is most dramatic on Windows.
+
Documentation
-------------
affectionately known as Robin strings, after their inventor, Robin
Friedrich.)
-- There's a simple assert statement, and a new exception AssertionError.
-For example, ``assert foo > 0'' is equivalent to ``if not foo > 0: raise
-AssertionError''. Sorry, the text of the asserted condition is not
-available; it would be too generate code for this. However, the text is
-displayed as part of the traceback! There's also a -O option to the
-interpreter that removes SET_LINENO instructions, assert statements; it
-uses and produces .pyo files instead of .pyc files. In the future it
-should be possible to write external bytecode optimizers that create better
-optimized .pyo files. Without -O, the assert statement actually generates
-code that first checks __debug__; if this variable is false, the assertion
-is not checked. __debug__ is a built-in variable whose value is
-initialized to track the -O flag (it's true iff -O is not specified). With
--O, no code is generated for assert statements, nor for code of the form
-``if __debug__: <something>''. Sorry, no further constant folding happens.
+- There's a simple assert statement, and a new exception
+AssertionError. For example, ``assert foo > 0'' is equivalent to ``if
+not foo > 0: raise AssertionError''. Sorry, the text of the asserted
+condition is not available; it would be too generate code for this.
+However, the text is displayed as part of the traceback! There's also
+a -O option to the interpreter that removes SET_LINENO instructions,
+assert statements; it uses and produces .pyo files instead of .pyc
+files (the line numbers are still available in the .pyo file, as a
+separate table; but the removal of the SET_LINENO instructions means
+that the debugger can't set breakpoints on lines in -O mode). In the
+future it should be possible to write external bytecode optimizers
+that create better optimized .pyo files. Without -O, the assert
+statement actually generates code that first checks __debug__; if this
+variable is false, the assertion is not checked. __debug__ is a
+built-in variable whose value is initialized to track the -O flag
+(it's true iff -O is not specified). With -O, no code is generated
+for assert statements, nor for code of the form ``if __debug__:
+<something>''. Sorry, no further constant folding happens.
Changes to builtin features
---------------------------
+- There's a new exception FloatingPointError (used only by Lee Busby's
+patches to catch floating point exceptions, at the moment).
+
+- The obsolete exception ConflictError has been deleted.
+
- There's a new function sys.exc_info() which returns the tuple
(sys.exc_type, sys.exc_value, sys.exc_traceback) in a thread-safe way.
dictionary implementation file is now called dictobject.c rather than
the confusing mappingobject.c.
-- The sort() methods for lists no longer uses the C library qsort(); I
-wrote my own quicksort implementation, with help from Tim Peters.
-This solves a bug in dictionary comparisons on some Solaris versions
-when Python is built with threads, and makes sorting lists even
-faster.
-
- The intrinsic function dir() is much smarter; it looks in __dict__,
__members__ and __methods__.
+- The intrinsic functions int(), long() and float() can now take a
+string argument and then do the same thing as string.atoi(),
+string.atol(), and string.atof(). No second 'base' argument is
+allowed, and complex() does not take a string (nobody cared enough).
+
- When a module is deleted, its globals are now deleted in two phases.
In the first phase, all variables whose name begins with exactly one
underscore are replaced by None; in the second phase, all variables
"extension classes", since it is triggered by the presence of a
__class__ attribute on the purported base class.
+- New optional parameter to the readlines() method of file objects.
+This indicates the number of bytes to read (the actual number of bytes
+read will be somewhat larger due to buffering reading until the end of
+the line). Some optimizations have also been made to speed it up (but
+not as much as read()).
+
New extension modules
---------------------
Fulton and other folks at Digital Creations. These are much more
efficient than their Python counterparts StringIO.py and pickle.py,
but don't support subclassing. cPickle.c clocks up to 1000 times
-faster than pickle.py. The pickle.py module has been updated to make
-it compatible with the new binary format that cPickle.c produces (by
+faster than pickle.py; cStringIO.c's improvement is less dramatic but
+still significant. The pickle.py module has been updated to make it
+compatible with the new binary format that cPickle.c produces (by
default it produces the old all-ASCII format compatible with the old
pickle.py, still much faster than pickle.py; it can read both
formats). A new helper module, copy_reg.py, is provided to register
- Various modules now export their type object: socket.SocketType,
array.ArrayType.
+- The socket module's accept() method now returns unknown addresses as
+a tuple rather than raising an exception. (This can happen in
+promiscuous mode.) Theres' also a new function getprotobyname().
+
- The pthread support for the thread module now works on most platforms.
- STDWIN is now officially obsolete. Support for it will eventually
- The binascii extension module is now hopefully fully debugged. (XXX
Oops -- Fredril Lundh promised me a fix that I never received.)
+- audioop.c: added a ratecv method
+
+- posixmodule.c: now exports the O_* flags (O_APPEND etc.). On
+Windows, also O_TEXT and O_BINARY. The 'error' variable (the
+exception is raises) is renamed -- its string value is now "os.error",
+so newbies don't believe they have to import posix (or nt) to catch
+it when they see os.error reported as posix.error.
+
+- A new version of the al (audio library) module for SGI was
+contributed by Sjoerd Mullender.
+
+- The regex module has a new function get_syntax() which retrieves the
+syntax setting set by set_syntax(). The code was also sanitized,
+removing worries about unclean error handling. See also below for its
+successor, re.py.
+
+- The "new" module (which creates new objects of various types) once
+again has a fully functioning new.function() method. Dangerous as
+ever!
+
New library modules
-------------------
limit to the size of uploads to POST (Skip Montanaro). Added a
'strict_parsing' option to all parsing functions (Jim Fulton). The
function parse_qs() now uses urllib.unquote() on the name as well as
-the value of fields (Clarence Gardner).
+the value of fields (Clarence Gardner). The FieldStorage class now
+has a __len__() method.
- httplib.py: the socket object is no longer closed; all HTTP/1.*
versions are now treated the same; and it is now thread-safe (by not
access to the standard error stream and the process id of the
subprocess possible.
-- Added timezone support to the rfc822.py module; also added
+- Added timezone support to the rfc822.py module, in the form of a
+getdate_tz() method and a parsedate_tz() function. Also added
recognition of some non-standard date formats, by Lars Wirzenius.
- mhlib.py: various enhancements, including almost compatible parsing
- Improvements for whrandom.py by Tim Peters: use 32-bit arithmetic to
speed it up, and replace 0 seed values by 1 to avoid degeneration.
-- Module ftplib.py: added support for parsing a .netrc file. Fred
-Drake.
+- Module ftplib.py: added support for parsing a .netrc file (Fred
+Drake). Also added an ntransfercmd() method to the FTP class, which
+allows access to the expected size of a transfer when available, and a
+parse150() function to the module which parses the corresponding 150
+response.
- urllib.py: the ftp cache is now limited to 10 entries. Added
quote_plus() method which is like qupte() but also replaces spaces
with '+', for encoding CGI form arguments. Catch all errors from the
ftp module. HTTP requests now add the Host: header line. The proxy
-variable names are now mapped to lower case, for Windows.
+variable names are now mapped to lower case, for Windows. The
+spliturl() function no longer erroneously throws away all data past
+the first newline. The basejoin() function now intereprets "../"
+correctly.
-- shelve.py: use cPickle and cStringIO when available.
+- shelve.py: use cPickle and cStringIO when available. Also added
+a sync() method, which calls the database's sync() method if there is
+one.
- The mimetools.py module now uses the available Python modules for
decoding quoted-printable, uuencode and base64 formats, rather than
includes functions to handle the funny encoding you sometimes see in mail
headers. It is now documented.
+- mailbox.py: Added BabylMailbox. Improved the way the mailbox is
+gotten from the environment.
+
+- Many more modules now correctly open files in binary mode when this
+is necessary on non-Unix platforms.
+
+- The copying functions in the undocumented module shutil.py are
+smarter.
+
+- The Writer classes in the formatter.py module now have a flush()
+method.
+
+- The Python bytecode disassembler module, dis.py, has been enhanced
+quite a bit. There's now one main function, dis.dis(), which takes
+almost any kind of object (function, module, class, instance, method,
+code object) and disassembles it; without arguments it disassembles
+the last frame of the last traceback. The other functions have
+changed slightly, too.
+
+- The imghdr.py module recognizes new image types: BMP, PNG.
+
+- The string module has a new function replace(str, old, new,
+[maxsplit]) which does substring replacements. It is actually
+implemented in C in the strop module. The functions [r]find() an
+[r]index() have an optional 4th argument indicating the end of the
+substring to search, alsoo implemented by their strop counterparts.
+(Remember, never import strop -- import string uses strop when
+available with zero overhead.)
+
Changes to the build process
----------------------------
Change to the Python/C API
--------------------------
-- I've completed the Grand Renaming, with the help of Roger Masse and Barry
-Warsaw. This makes reading or debugging the code much easier. Many other
-unrelated code reorganizations have also been carried out.
+- I've completed the Grand Renaming, with the help of Roger Masse and
+Barry Warsaw. This makes reading or debugging the code much easier.
+Many other unrelated code reorganizations have also been carried out.
+The allobjects.h header file is gone; instead, you would have to
+include Python.h followed by rename2.h. But you're better off running
+Tools/scripts/fixcid.py -s Misc/RENAME on your source, so you can omit
+the rename2.h; it will disappear in the next release.
+
+- The API functions in the file cgensupport.c are no longer
+supported. This file has been moved to Modules and is only ever
+compiled when the SGI specific 'gl' module is built.
- PyObject_Compare() can now raise an exception. Check with
PyErr_Occurred(). The comparison function in an object type may also
is deprecated (it is nothing more than Py_Finalize() followed by
exit()).
-- There are no known memory leaks. While Py_Finalize() doesn't free
-*all* allocated memory (some of it is hard to track down), repeated
-calls to Py_Finalize() and Py_Initialize() do not create unaccessible
-heap blocks.
+- There are no known memory leaks left. While Py_Finalize() doesn't
+free *all* allocated memory (some of it is hard to track down),
+repeated calls to Py_Finalize() and Py_Initialize() do not create
+unaccessible heap blocks.
- There is now explicit per-thread state. (Inspired by, but not the
same as, Greg Stein's free threading patches.)
instead of clearing exceptions. This fixes an obscure bug where using
these would clear a pending exception, discovered by Just van Rossum.
+- PyArg_GetInt() is gone.
+
+- It's no longer necessary to include graminit.h when calling one of
+the extended parser API functions. The three public grammar start
+symbols are now in Python.h as Py_single_input, Py_file_input, and
+Py_eval_input.
+
Tkinter
-------
-- New standard dialog modules for Tkinter: tkColorChooser.py,
-tkCommonDialog.py, tkMessageBox.py, tkFileDialog.py, tkSimpleDialog.py
-These interface with the new Tk dialog scripts. Contributed by
-Fredrik Lundh.
+- On popular demand, _tkinter once again installs a hook for readline
+that processes certain Tk events while waiting for the user to type
+(using PyOS_InputHook).
+
+- A patch by Craig McPheeters plugs the most obnoxious memory leaks,
+caused by command definitions referencing widget objects beyond their
+lifetime.
+
+- New standard dialog modules: tkColorChooser.py, tkCommonDialog.py,
+tkMessageBox.py, tkFileDialog.py, tkSimpleDialog.py These interface
+with the new Tk dialog scripts. Contributed by Fredrik Lundh.
- Tkinter.py: when the first Tk object is destroyed, it sets the
hiddel global _default_root to None, so that when another Tk object is
- Tools/scripts/h2py.py now supports C++ comments.
-- The pystone.py script is upgraded to version 1.1; there was a bug in
-version 1.0 (distributed with Python 1.4) that leaked memory. Also,
-in 1.1, the LOOPS variable is incremented to 10000.
+- Tools/scripts/pystone.py script is upgraded to version 1.1; there
+was a bug in version 1.0 (distributed with Python 1.4) that leaked
+memory. Also, in 1.1, the LOOPS variable is incremented to 10000.
+
+- Demo/classes/Rat.py completely rewritten by Sjoerd Mullender.
Windows (NT and 95)
- The freeze tool now works on Windows.
-- See also the Tkinter category for a note on _tkinter.createfilehandler().
+- See also the Tkinter category for a sad note on
+_tkinter.createfilehandler().
+- The truncate() method for file objects now works on Windows.
-Mac
----
-
-- As always, the Macintosh port was done by Jack Jansen. See his
-separate announcement for the Mac specific source code and the binary
-distribution(s).
+- Py_Initialize() is no longer called when the DLL is loaded. You
+must call it yourself. (And you can't call it twice -- it's a fatal
+error to call it when Python is already initialized.)
-More
-----
-
-The following items should be expanded upon:
-
-- formatter.*Writer.flush
-
-- dis.{cmp_op, hascompare}
+Mac
+---
-- ftplib: FTP.ntransfercmd, parse150
+- As always, the Macintosh port will be done by Jack Jansen. He will
+make a separate announcement for the Mac specific source code and the
+binary distribution(s) when these are ready.
-- imghdr recognizes bmp, png
-- mimify base64 support
+Fixed after 1.5a3 was released
+------------------------------
-- new.function revived
+The following changes have been made to the source base after the
+release of 1.5a3. These need to be merged into their respective
+categories for the next release.
-- cgi.FieldStorage: __len__ added
+- regrtest.py is slightly more verbose, printing the name of each test
+as it runs them.
-New exceptions:
- FloatingPointError
-Deleted exception:
- ConflictError
+- fileobject.c: ftell() on Linux discards all buffered data; changed
+read() code to use lseek() instead
-> audioop.ratecv
+- configure.in, configure, importdl.c: NeXT sharedlib fixes
-> posix.O_APPEND
-> posix.O_CREAT
-> posix.O_DSYNC
-> posix.O_EXCL
-> posix.O_NDELAY
-> posix.O_NOCTTY
-> posix.O_NONBLOCK
-> posix.O_RDONLY
-> posix.O_RDWR
-> posix.O_RSYNC
-> posix.O_SYNC
-> posix.O_TRUNC
-> posix.O_WRONLY
- posix.O_TEXT
- posix.O_BINARY
-(also in os, of course)
+- tupleobject.c: PyTuple_SetItem asserts refcnt==1
-> regex.get_syntax
+- resource.c: Change how and when to declare getpagesize() and
+getrlimit()
-> socket.getprotobyname
+- mpzmodule.c: CPP hack to support GMP 1.x for real
-> strop.replace
-Also string.replace
+- importdl.c, configure*: set sharedlib extensions properly for NeXT
-- Jack's buffer interface!
- - supported by regex module!
+- configure*, Makefile.in, Modules/Makefile.pre.in: AIX shared libraries
+fixed; moved addition of PURIFY to LINKCC to configure
-- posix.error, nt.error renamed to os.error
+- reopmodule.c, regexmodule.c, regexpr.c, zlibmodule.c: casts to shut
+up Mac compiler
-- rfc822 getdate_tz and parsedate_tz
+- _tkinter.c: removed buggy mac #ifndef
-- shelve.*.sync
+- Doc: various Mac documentation changes, added docs for 'ic' module
-- shutil improved interface
+- PC/make_nt.in: deleted
-- socket.getprotobynameo
+- test_time.py, test_strftime.py: tweaks to catch %Z
-- new al module for SGI
+- test_rotor.py: print b -> print `b`
-Obsolete: cgensupport.[ch] are now in Modules and only linked with glmodule.c.
+- Tkinter.py: (tagOrId) -> (tagOrId,)
-- much faster file.read() and readlines() on windows
+- faqwiz.py: Recognize https:// as URL
projects / python / commitdiff