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+++++++++++
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.)**
|
