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Diffstat (limited to 'Misc/NEWS')
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@@ -0,0 +1,618 @@ + + + +New since 1.5a2 +--------------- + +The following items are only relevant if you previously used Python +1.5a2: + +- The strftime test should now succeed on Windows and Mac platforms, +too. It still fails on some Linux platforms; I believe that this is a +problem in the C library on those platforms. + + + +What's new in this release? +--------------------------- + +I haven't kept track closely, so here are just a few highlights. For +the final release, I will go through all my RCS logs and distill a +complete list. Note that the biggest unfinished project is +documentation. + +XXX To be expanded: + +- Tools/webchecker + +- Lee Busby's SIGFPE mods and modules fpectl, fpetest + +- formatter.*Writer.flush + +- dis.{cmp_op, hascompare} + +- ftplib: FTP.ntransfercmd, Netrc, parse150 + +- httplib.HTTP_VERSIONS_ACCEPTED + +- new module keyword + +- imghdr recognizes bmp, png + +- mhlib, parsesequence improved + +- mimify base64 support + +- new.function revived + +- popen2.popen3 added + +- new module pprint + +- cgi.FieldStorage: __len__ added + +New exceptions: + FloatingPointError +Deleted exception: + ConflictError + +> audioop.ratecv + +> 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) + +> regex.get_syntax + +> socket.getprotobyname + +> strop.replace +Also string.replace + +- Jack's buffer interface! + - supported by regex module! + +- improved dir() semantics + +- posix.error, nt.error renamed to os.error + +- rfc822 getdate_tz and parsedate_tz + +- shelve.*.sync + +- shutil improved interface + +- socket.getprotobynameo + +- _xdrmodule is gone (in favor of structmodule) + +- xdrlib.Unpacker.get_buffer + +- much improved structmodule + +- Tkinter upgraded (as always) + +- new al module for SGI + +- file object readinto methods + +- tktrace??? + +Obsolete: cgensupport.[ch] are now in Modules and only linked with glmodule.c. + +- much faster file.read() and readlines() on windows + +====================================================================== + +- PyObject_Compare() can now raise an exception. Check with +PyErr_Occurred(). The comparison function in an object type may also +raise an exception. + +- The slice interface uses an upper bound of INT_MAX when no explicit +upper bound is given (e.x. for a[1:]). It used to ask the object for +its length and do the calculations. + +- I've completed the Grand Renaming, with the help of Roger Masse and +Barry Warsaw. Many other unrelated code reorganizations have also +been carried out. + +- As far as I can tell, neither gcc -Wall nor the Microsoft compiler +emits a single warning any more when compiling Python. + +- It's much faster (almost twice for pystone.py -- see Tools/scripts.) + +- Unless I hear a lot of protest, private variables with leading +double underscore are now a permanent feature of the language. I +can't label them "experimental" forever. + +- New extension modules cStringIO.c and cPickle.c, written by Jim +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 +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 +extensions to the pickling code. (These are now identical to the +release 0.3 from Digital Creations.) + +- New (still experimental) Perl-style regular expression module, +re.py, which uses a new interface for matching as well as a new +syntax; the new interface avoids the thread-unsafety of the regex +interface. This comes with a helper extension reopmodule.c and vastly +rewritten regexpr.c. Most work on this was done by Jeffrey Ollie, Tim +Peters, and Andrew Kuchling. See the documentation libre.tex. In +1.5, the old regex module is still fully supported; in the future, it +will become obsolete. + +- New string literal syntax for "raw strings". Prefixing a string +literal with the letter r (or R) disables all escape processing in the +string; for example, r'\n' is a two-character string consisting of a +backslash followed by the letter n. This combines with all forms of +string quotes. An embedded quote prefixed with a backslash does not +terminate the string, but the backslash is still included in the +string; for example, r'\'' is a two-character string consisting of a +backslash and a quote. Raw strings are also affectionately known as +Robin strings, after their inventor, Robin Friedrich. + +- New project files for Developer Studio (Visual C++) 5.0 for Windows +NT (the old VC++ 4.2 Makefile is also still supported, but will +eventually be withdrawn due to its bulkiness). + +- New extension module zlibmodule.c, interfacing to the free zlib +library (gzip compatible compression). There's also a module gzip.py +which provides a higher level interface. Written by Andrew Kuchling +and Jeremy Hylton. + +- New tool: faqwiz -- the CGI script that is used to maintain the +Python FAQ (http://grail.cnri.reston.va.us/cgi-bin/faqw.py). In +Tools/faqwiz. + +- New tool: webchecker -- a simple extensible web robot that, when +aimed at a web server, checks that server for dead links. Available +are a command line utility as well as a Tkinter based GUI version. In +Tools/webchecker. A simplified version of this program is dissected +in my article in O'Reilly's WWW Journal, the issue on Scripting +Languages (Vol 2, No 2); Scripting the Web with Python (pp 97-120). +Includes a parser for robots.txt files by Skip Montanaro. + +- New small tools: cvsfiles.py (prints a list of all files under CVS +in a particular directory tree), treesync.py (a rather Guido-specific +script to synchronize two source trees, one on Windows NT, the other +one on Unix under CVS but accessible from the NT box), and logmerge.py +(sort a collection of RCS or CVS logs by date). In Tools/scripts. + +- The freeze script now also works under Windows (NT). Another +feature allows the -p option to be pointed at the Python source tree +instead of the installation prefix. This was loosely based on part of +xfreeze by Sam Rushing and Bill Tutt. + +- A new regression test suite is provided, which tests most of the +standard and built-in modules. The regression test is run by invoking +the script Lib/test/regrtest.py. Barry Warsaw wrote the test harnass; +he and Roger Masse contributed most of the new tests. + +- 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. + +- 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 +created it becomes the new default root. Other miscellaneous +changes and fixes. + +- Many new pieces of library documentation were contributed, mostly by +Andrew Kuchling. Even cmath is now documented! There's also a +chapter of the library manual, "libundoc.tex", which provides a +listing of all undocumented modules, plus their status (e.g. internal, +obsolete, or in need of documentation). Also contributions by Sue +Williams, Skip Montanaro, and some module authors who succumbed to +pressure to document their own contributed modules :-). Note that +printing the documentation now kills fewer trees -- the margins have +been reduced. + +- I have started documenting the Python/C API. Unfortunately this +project hasn't been completed yet. It will be complete before the +final release of Python 1.5, though. + +- The mimify.py module now has documentation, and includes functions +to handle the funny encoding you sometimes see in mail headers. + +- The default module search path is now much saner. Both on Unix and +Windows, it is essentially derived from the path to the executable +($PYTHONHOME can be used to override). The value of $PYTHONPATH on +Windows is now inserted in front of the default path, like in Unix +(instead of overriding the default path). + +- Support for Win32S (the 32-bit Windows API under Windows 3.1) is +basically withdrawn. If it works for you, you're lucky. + +- On Win32 platforms (Windows NT and 95), there's a new extension +module, msvcrt.c, which provides various low-level operations defined +in the Microsoft Visual C++ Runtime Library. These include locking(), +setmode(), get_osfhandle(), set_osfhandle(), and console I/O functions +like kbhit(), getch() and putch(). + +- The way GNU readline is configured is totally different. The +--with-readline configure option is gone. It is now an extension +module, which may be loaded dynamically. You must enable it (and +specify the correct linraries to link with) in the Modules/Setup file. +Importing the module installs some hooks which enable command line +editing. When the interpreter shell is invoked interactively, it +attempts to import the readline module; when this fails, the default +input mechanism is used. The hook variables are PyOS_InputHook and +PyOS_ReadlineFunctionPointer. (Code contributed by Lee Busby, with +ideas from William Magro.) + +- New Unix extension module resource.c, by Jeremy Hylton, provides +access to getrlimit(), getrusage(), setrusage(), getpagesize(), and +related symbolic constants. + +- Support for multiple independent interpreters. See Doc/api.tex, +functions Py_NewInterpreter() and Py_EndInterpreter(). Since the +documentation is incomplete, also see the new Demo/pysvr example +(which shows how to use these in a threaded application) and the +source code. + +- There is now a Py_Finalize() function which "de-initializes" +Python. It is possible to completely restart the interpreter +repeatedly by calling Py_Finalize() followed by Py_Initialize(). A +change of functionality in Py_Initialize() means that it is now a +fatal error to call it while the interpreter is already initialized. +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. + +- New function sys.exc_info() returns the tuple (sys.exc_type, +sys.exc_value, sys.exc_traceback) in a thread-safe way. + +- The semantics of try-except have changed subtly so that calling a +function in an exception handler that itself raises and catches an +exception no longer overwrites the sys.exc_* variables. This also +alleviates the problem that objects referenced in a stack frame that +caught an exception are kept alive until another exception is caught +-- the sys.exc_* variables are restored to their previous value when +returning from a function that caught an exception. + +- There is now explicit per-thread state. (Inspired by, but not the +same as, Greg Stein's free threading patches.) + +- There is now better support for threading C applications. There are +now explicit APIs to manipulate the interpreter lock. Read the source +or the Demo/pysvr example; the new functions are +PyEval_{Acquire,Release}{Lock,Thread}(). + +- New wrappers around malloc() and friends: Py_Malloc() etc. call +malloc() and call PyErr_NoMemory() when it fails; PyMem_Malloc() call +just malloc(). Use of these wrappers could be essential if multiple +memory allocators exist (e.g. when using certain DLL setups under +Windows). (Idea by Jim Fulton.) + +- Numerous source cleanups. + +- There's a simple assert statement, and a new exception +AssertionError, and a built-in variable __debug__. For example, +``assert foo > 0'' is equivalent to ``if __debug__ and 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 squeezes SET_LINENO instructions, assert +statements and ``if __debug__'' code; 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. + +- New build procedure: a single library, libpython1.5.a, is now built, +which contains absolutely everything except for a one-line main() +program (which calls Py_Main(argc, argv) to start the interpreter +shell). This makes life much simpler for applications that need to +embed Python. The serial number of the build is now included in the +version string (sys.version). + +- New module keyword.py exports knowledge about Python's built-in +keywords. (New version by Ka-Ping Yee.) + +- New examples (Demo/extend) that show how to use the generic +extension makefile (Misc/Makefile.pre.in). + +- New module pprint.py (with documentation) which supports +pretty-printing of lists, tuples, & dictionaries recursively. By Fred +Drake. + +- New module code.py. The function code.compile_command() can +determine whether an interactively entered command is complete or not, +distinguishing incomplete from invalid input. + +- Module codehack.py is now completely obsolete. + +- Revamped module tokenize.py is much more accurate and has an +interface that makes it a breeze to write code to colorize Python +source code. Contributed by Ka-Ping Yee. + +- 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). + +- A set of patches from Lee Busby has been integrated that make it +possible to catch floating point exceptions. Use the configure option +--with-fpectl to enable the patches; the extension modules fpectl and +fpetest provide control to enable/disable and test the feature, +respectively. + +- New extension puremodule.c, by Barry Warsaw, which interfaces to the +Purify(TM) C API. See also the file Misc/PURIFY.README. It is also +possible to enable Purify by simply setting the PURIFY Makefile +variable in the Modules/Setup file. + +- The struct extension module has several new features to control byte +order and word size. It supports reading and writing IEEE floats even +on platforms where this is not the native format. + +- There is now a library module xdr.py which can read and write the +XDR data format as used by Sun RPC, for example. It uses the struct +module. + +- 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. + +- New C API PyImport_Import() which uses whatever __import__() hook +that is installed for the current execution environment. By Jim +Fulton. + +- The _tkinter.c extension module has been revamped. It now support +Tk versions 4.1 through 8.0; support for 4.0 has been dropped. It +works well under Windows and Mac (with the latest Tk ports to those +platforms). It also supports threading -- it is safe for one +(Python-created) thread to be blocked in _tkinter.mainloop() while +other threads modify widgets. (To make the changes visible, those +threads must use update_idletasks()method.) Unfortunately, on Windows +and Mac, Tk 8.0 no longer supports CreateFileHandler, so +_tkinter.createfilehandler is not available on those platforms. I +will have to rethink how to interface with Tcl's lower-level event +mechanism, or with its channels (which are like Python's file-like +objects). + +- New "buffer" interface. Certain objects (e.g. strings, arrays) now +support the "buffer" protocol. Buffer objects are acceptable whenever +formerly a string was required for a write operation; mutable buffer +objects can be the target of a read operation using the +f.readinto(buffer). Contribution bty Jack Jansen. (Needs +documentation.) + +- In ihooks.py, ModuleLoader.load_module() now closes the file under +all circumstances. + +- The tempfile.py module has a new class, TemporaryFile, which creates +an open temporary file that will be deleted automatically when +closed. This works on Windows and MacOS as well as on Unix. (Jim +Fulton.) + +- Changes to the cgi.py module: Most imports are now done at the +top of the module, which provides a speedup when using ni (Jim +Fulton). The problem with file upload to a Windows platform is solved +by using the new tempfile.TemporaryFile class; temporary files are now +always opened in binary mode (Jim Fulton). The cgi.escape() function +now takes an optional flag argument that quotes '"' to '"'. It +is now possible to invoke cgi.py from a command line script, to test +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). + +- String interning: dictionary lookups are faster when the lookup +string object is the same object as the key in the dictionary, not +just a string with the same value. This is done by having a pool of +"interned" strings. Most names generated by the interpreter are now +automatically interned, and there's a new built-in function intern(s) +that returns the interned version of a string. Interned strings are +not a different object type, and interning is totally optional, but by +interning most keys a speedup of about 15% was obtained for the +pystone benchmark. + +- 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 +using the regex module). + +- BaseHTTPModule.py: treat all HTTP/1.* versions the same. + +- The popen2.py module is now rewritten using a class, which makes +access to the standard error stream and the process id of the +subprocess possible. + +- The support for shared libraries under AIX is now simpler and more +robust. Thanks to Vladimir Marangozov for revamping his own patches! + +- 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 +are deleted. This makes it possible to have global objects whose +destructors depend on other globals. The deletion order within each +phase is still random. + +- The Modules/makesetup script now reads a file Setup.local as well as +a file Setup. Most changes to the Setup script can be done by editing +Setup.local instead, which makes it easier to carry a particular setup +over from one release to the next. + +- It is no longer an error for a function to be called without a +global variable __builtins__ -- an empty directory will be provided +by default. + +- Some speedup by using separate free lists for method objects (both +the C and the Python variety) and for floating point numbers. + +- Big speedup by allocating frame objects with a single malloc() call. +The Python/C API for frames is changed (you shouldn't be using this +anyway). + +- It is now possible for an extension module's init function to fail +non-fatally, by calling one of the PyErr_* functions and returning. + +- The PyInt_AS_LONG() and PyFloat_AS_DOUBLE() macros now cast their +argument to the proper type, like the similar PyString macros already +did. (Suggestion by Marc-Andre Lemburg.) + +- The fcntl extension module now exports the needed symbolic +constants. (Formerly these were in FCNTL.py which was not available +or correct for all platforms.) + +- Guido's corollary of the Don Beaudry hack: it is now possible to do +metaprogramming by using an instance as a base class. Not for the +faint of heart; and undocumented as yet, but basically if a base class +is an instance, its class will be instantiated to create the new +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. + +- Plugged the two-byte memory leak in the tokenizer when reading an +interactive EOF. + +- Added timezone support to the rfc822.py module; also added +recognition of some non-standard date formats, by Lars Wirzenius. + +- mhlib.py: various enhancements, including almost compatible parsing +of message sequence specifiers without invoking a subprocess. Also +added a createmessage() method by Lars Wirzenius. + +- The StringIO.StringIO class now supports readline(nbytes). (Lars +Wirzenius.) + +- Dictionary objects have several new methods; clear() and copy() have +the obvious semantics, while update(d) merges the contents of another +dictionary d into this one, overriding existing keys. BTW, the +dictionary implementation file is now called dictobject.c rather than +the confusing mappingobject.c. + +- UserDict.py supports the new dictionary methods as well. + +- The intrinsic function dir() is much smarter; it looks in __dict__, +__members__ and __methods__. + +- The silly -s command line option and the corresponding +PYTHONSUPPRESS environment variable and the Py_SuppressPrint global +flag are gone. + +- On Windows, -u not only sets the standard I/O streams to unbuffered +status, but also sets them in binary mode. + +- Some of the Py_Get* function, like Py_GetVersion() (but not yet +Py_GetPath()) are now declared as returning a const char *. (More +should follow.) + +- Speedup by inlining some common opcodes for common operand types +(e.g. i+i, i-i, and list[i]). Fredrik Lundh. + +- The extension modules dbm, gdbm and bsddb now check that the +database is still open before making any new calls. + +- Various small fixes to the nntplib.py module that I can't bother to +document in detail. + +- There is a cache for results in urlparse.urlparse(); its size limit +is set to 20 (not 2000 as it was in earlier alphas). + +- Small speedup by reordering the method tables of some common +objects (e.g. list.append is now first). + +- The modules base64.py, uu.py and quopri.py can now be used as simple +command line utilities. + +- The binascii extension module is now hopefully fully debugged. (XXX +Oops -- Fredril Lundh promised me a fix that I never received.) + +- The mimetools.py module now uses the available Python modules for +decoding quoted-printable, uuencode and base64 formats, rather than +creating a subprocess. + +- The python debugger (pdb.py, and its base class bdb.py) now support +conditional breakpoints. See the docs. + +- The configure script now detects whether malloc(0) returns a NULL +pointer or a valid block (of length zero). This avoids the nonsense +of always adding one byte to all malloc() arguments on most platforms. + +- 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. + +- Fix a bug where multiple anonymous tuple arguments would be mixed up +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. + +- Module ftplib.py: added support for parsing a .netrc file. Fred +Drake. + +- 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. + +- The posix module (and hence os.py!) now has doc strings! Thanks to +Neil Schemenauer. + +- shelve.py: use cPickle and cStringIO when available. + +- Various modules now export their type object: socket.SocketType, +array.ArrayType. + +- ntpath.py supports ~ to $HOME expansion in expanduser(). + +- The pthread support now works on most platforms. + +- New variable sys.executable points to the executable file for the +Python interpreter, if known. + +- On Windows, sys.prefix and sys.exec_prefix point to the directory +where Python is installed, or to the top of the source tree, if it was +run from there. + +- 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. + +- STDWIN is now officially obsolete. Support for it will eventually +be removed from the distribution. + +- The configure script is smarter about C compiler options; e.g. with +gcc it uses -O2 and -g when possible, and on some other platforms it +uses -Olimit 1500 to avoid a warning from the optimizer about the main +loop in ceval.c (which has more than 1000 basic blocks). + +- Changed the run-time library to check for exceptions after object +comparisons. PyObject_Compare() can now return an exception; use +PyErr_Occurred() to check (there is *no* special return value). + +- PyFile_WriteString() and Py_Flushline() now return error indicators +instead of clearing exceptions. This fixes an obscure bug where using +these would clear a pending exception, discovered by Just van Rossum. + +- Most problems on 64-bit platforms should now be fixed. Andrew +Kuchling helped. Some uncommon extension modules are still not +clean (image and audio ops?). + |