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Guido van Rossum 1997-08-18 21:17:32 +00:00
parent 8a81d27d58
commit 2da391f387
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335
Misc/NEWS
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@ -3,19 +3,37 @@ What's new in this release?
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
@ -30,6 +48,20 @@ when using the debugger or profiler (reported by Just van Rossum).
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.
@ -37,7 +69,8 @@ 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.
@ -52,6 +85,12 @@ types (e.g. i+i, i-i, and list[i]). Fredrik Lundh.
- 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
-------------
@ -96,25 +135,34 @@ consisting of a backslash and a quote. (Raw strings are also
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.
@ -153,15 +201,14 @@ dictionary d into this one, overriding existing keys. BTW, the
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
@ -181,6 +228,12 @@ class. Jim Fulton will love it -- it also works with instances of his
"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
---------------------
@ -189,8 +242,9 @@ 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
@ -231,6 +285,10 @@ database is still open before making any new calls.
- 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
@ -239,6 +297,26 @@ be removed from the distribution.
- 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
-------------------
@ -298,7 +376,8 @@ cgi scripts more easily outside an http server. There's an optional
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
@ -310,7 +389,8 @@ using the regex module).
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
@ -325,16 +405,24 @@ Wirzenius.) (Of course, you should be using cStringIO for performance.)
- 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
@ -356,6 +444,35 @@ is set to 20 (not 2000 as it was in earlier alphas).
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
----------------------------
@ -408,9 +525,17 @@ of always adding one byte to all malloc() arguments on most platforms.
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
@ -435,10 +560,10 @@ The old, half-hearted Py_Cleanup() routine is gone. Use of Py_Exit()
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.)
@ -477,14 +602,28 @@ PyErr_Occurred() to check (there is *no* special return value).
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
@ -541,9 +680,11 @@ extension makefile (Misc/Makefile.pre.in).
- 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)
@ -576,82 +717,64 @@ expansion in expanduser().
- 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.
- 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.)
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).
- 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.
More
----
Fixed after 1.5a3 was released
------------------------------
The following items should be expanded upon:
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.
- formatter.*Writer.flush
- regrtest.py is slightly more verbose, printing the name of each test
as it runs them.
- dis.{cmp_op, hascompare}
- fileobject.c: ftell() on Linux discards all buffered data; changed
read() code to use lseek() instead
- ftplib: FTP.ntransfercmd, parse150
- configure.in, configure, importdl.c: NeXT sharedlib fixes
- imghdr recognizes bmp, png
- tupleobject.c: PyTuple_SetItem asserts refcnt==1
- mimify base64 support
- resource.c: Change how and when to declare getpagesize() and
getrlimit()
- new.function revived
- mpzmodule.c: CPP hack to support GMP 1.x for real
- cgi.FieldStorage: __len__ added
- importdl.c, configure*: set sharedlib extensions properly for NeXT
New exceptions:
FloatingPointError
Deleted exception:
ConflictError
- configure*, Makefile.in, Modules/Makefile.pre.in: AIX shared libraries
fixed; moved addition of PURIFY to LINKCC to configure
> audioop.ratecv
- reopmodule.c, regexmodule.c, regexpr.c, zlibmodule.c: casts to shut
up Mac compiler
> 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)
- _tkinter.c: removed buggy mac #ifndef
> regex.get_syntax
- Doc: various Mac documentation changes, added docs for 'ic' module
> socket.getprotobyname
- PC/make_nt.in: deleted
> strop.replace
Also string.replace
- test_time.py, test_strftime.py: tweaks to catch %Z
- Jack's buffer interface!
- supported by regex module!
- test_rotor.py: print b -> print `b`
- posix.error, nt.error renamed to os.error
- Tkinter.py: (tagOrId) -> (tagOrId,)
- rfc822 getdate_tz and parsedate_tz
- shelve.*.sync
- shutil improved interface
- socket.getprotobynameo
- new al module for SGI
Obsolete: cgensupport.[ch] are now in Modules and only linked with glmodule.c.
- much faster file.read() and readlines() on windows
- faqwiz.py: Recognize https:// as URL