+++++++++++ 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. - Unify range() and xrange(). - Rework the standard I/O library to use bytes for binary files. - Make strings all Unicode. - Get rid of various compatibility-related flags (e.g. division flags). Core and Builtins ----------------- - 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. - Removed the exceptions module, all the exceptions are already builtin. - 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 (`x`), <> - Removed these Python builtins: apply(), coerce() - Removed these Python methods: {}.has_key - Removed these Python slots: __coerce__, __div__, __idiv__, __rdiv__ - Removed these attributes from Python modules: * operator module: div, idiv, __div__, __idiv__ - 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 - Removed these opcodes: BINARY_DIVIDE, INPLACE_DIVIDE, UNARY_CONVERT - zip returns an iterator - Additions: set literals, ellipsis literal Extension Modules ----------------- - isCallable() and sequenceIncludes() have been removed from the operator module. Library ------- - Patch #1680961: atexit has been reimplemented in C. - Removed all traces of the sets module. Build ----- C API ----- Tests ----- Documentation ------------- Mac --- New platforms ------------- Tools/Demos ----------- **(For information about older versions, consult the HISTORY file.)**