+++++++++++ Python News +++++++++++ (editors: check NEWS.help for information about editing NEWS using ReST.) What's New in Python 3000? ========================== *Release date: XX-XXX-200X* TO DO ----- - See PEP 3000, 3100. - Weed really old/weird stuff from the library. - Use io.py instead of C stdio everywhere. - Make strings all Unicode (see branches/py3k-struni). - Get rid of various compatibility-related flags (e.g. division flags). Core and Builtins ----------------- - None, True, False are now keywords. - PEP 3119: isinstance() and issubclass() can be overridden. - Remove BaseException.message. - Remove tuple parameter unpacking (PEP 3113). - Remove the f_restricted attribute from frames. This naturally leads to teh removal of PyEval_GetRestricted() and PyFrame_IsRestricted(). - PEP 3132 was accepted. That means that you can do ``a, *b = range(5)`` to assign 0 to a and [1, 2, 3, 4] to b. - range() now returns an iterator rather than a list. Floats are not allowed. xrange() is no longer defined. - Patch #1660500: hide iteration variable in list comps, add set comps and use common code to handle compilation of iterative expressions - By default, != returns the opposite of ==, unless the latter returns NotImplemented. - Patch #1680961: sys.exitfunc has been removed and replaced with a private C-level API. - PEP 3115: new metaclasses: the metaclass is now specified as a keyword arg in the class statement, which can now use the full syntax of a parameter list. Also, the metaclass can implement a __prepare__ function which will be called to create the dictionary for the new class namespace. - The long-deprecated argument "pend" of PyFloat_FromString() has been removed. - The dir() function has been extended to call the __dir__() method on its argument, if it exists. If not, it will work like before. This allows customizing the output of dir() in the presence of a __getattr__(). - Removed indexing/slicing on BaseException. - input() became raw_input(): the name input() now implements the functionality formerly known as raw_input(); the name raw_input() is no longer defined. - Classes listed in an 'except' clause must inherit from BaseException. - PEP 3106: dict.iterkeys(), .iteritems(), .itervalues() are now gone; and .keys(), .items(), .values() return dict views. - PEP 3105: print is now a function. Also (not in the PEP) the 'softspace' attribute of files is now gone (since print() doesn't use it). A side effect of this change is that you can get incomplete output lines in interactive sessions: >>> print(42, end="") 42>>> We may be able to fix this after the I/O library rewrite. - PEP 3102: keyword-only arguments. - Int/Long unification is complete. The 'long' built-in type and literals with trailing 'L' or 'l' have been removed. Performance may be sub-optimal (haven't really benchmarked). - 'except E, V' must now be spelled as 'except E as V' and deletes V at the end of the except clause; V must be a simple name. - Added function annotations per PEP 3107. - Added nonlocal declaration from PEP 3104 >>> def f(x): ... def inc(): ... nonlocal x ... x += 1 ... return x ... return inc ... >>> inc = f(0) >>> inc() 1 >>> inc() 2 - Moved intern() to sys.intern(). - exec is now a function. - Renamed nb_nonzero to nb_bool and __nonzero__ to __bool__. - Classic classes are a thing of the past. All classes are new style. - Exceptions *must* derive from BaseException. - Integer division always returns a float. The -Q option is no more. All the following are gone: * PyNumber_Divide and PyNumber_InPlaceDivide * __div__, __rdiv__, and __idiv__ * nb_divide, nb_inplace_divide * operator.div, operator.idiv, operator.__div__, operator.__idiv__ (Only __truediv__ and __floordiv__ remain, not sure how to handle them if we want to re-use __div__ and friends. If we do, it will make it harder to write code for both 2.x and 3.x.) - 'as' and 'with' are keywords. - Absolute import is the default behavior for 'import foo' etc. - Removed support for syntax: backticks (ie, `x`), <> - Removed these Python builtins: apply(), callable(), coerce(), file(), reduce(), reload() - Removed these Python methods: {}.has_key - Removed these opcodes: BINARY_DIVIDE, INPLACE_DIVIDE, UNARY_CONVERT - Remove C API support for restricted execution. - zip returns an iterator - Additions: set literals, ellipsis literal - Added class decorators per PEP 3129. Extension Modules ----------------- - Remove the imageop module. Obsolete long with its unit tests becoming useless from the removal of rgbimg and imgfile. - Removed these attributes from Python modules: * operator module: div, idiv, __div__, __idiv__, isCallable, sequenceIncludes * sys module: exc_clear(), exc_type, exc_value, exc_traceback Library ------- - Remove the compiler package. Use of the _ast module and (an eventual) AST -> bytecode mechanism. - Removed these modules: * Bastion, bsddb185, exceptions, md5, MimeWriter, mimify, popen2, rexec, sets, sha, stringold, strop, timing, xmllib. - Remove obsolete IRIX modules: al/AL, cd/CD, cddb, cdplayer, cl/CL, DEVICE, ERRNO, FILE, fl/FL, flp, fm, GET, gl/GL, GLWS, IN, imgfile, IOCTL, jpeg, panel, panelparser, readcd, sgi, sv/SV, torgb, WAIT. - Remove obsolete functions: * commands.getstatus(), os.popen*, - Remove functions in the string module that are also string methods. - Remove support for long obsolete platforms: plat-aix3, plat-irix5. - Remove xmlrpclib.SlowParser. It was based on xmllib. - Patch #1680961: atexit has been reimplemented in C. Build ----- C API ----- - Removed these Python slots: __coerce__, __div__, __idiv__, __rdiv__ - Removed these C APIs: PyNumber_Coerce(), PyNumber_CoerceEx() - Removed these C slots/fields: nb_divide, nb_inplace_divide - Removed these macros: staticforward, statichere, PyArg_GetInt, PyArg_NoArgs - Removed these typedefs: intargfunc, intintargfunc, intobjargproc, intintobjargproc, getreadbufferproc, getwritebufferproc, getsegcountproc, getcharbufferproc Tests ----- Documentation ------------- Mac --- - The cfmfile was removed. New platforms ------------- Tools/Demos ----------- **(For information about older versions, consult the HISTORY file.)**