[Python-3000-checkins] r67490 - python/branches/py3k/Doc/whatsnew/3.0.rst
guido.van.rossum
python-3000-checkins at python.org
Wed Dec 3 05:15:36 CET 2008
Author: guido.van.rossum
Date: Wed Dec 3 05:15:35 2008
New Revision: 67490
Log:
More cleanup. Moved all Unicode and str/bytes info to the text/data
subsection in common pitfalls, rather than spreading it out. Made
this the last subsection of common pitfalls. All XXX comments are now
gone. I'm sure much is still missing, we'll have to clean that up
post 3.0. At least all PEPs and all implemented items in PEP 3100
have at least one mention.
Modified:
python/branches/py3k/Doc/whatsnew/3.0.rst
Modified: python/branches/py3k/Doc/whatsnew/3.0.rst
==============================================================================
--- python/branches/py3k/Doc/whatsnew/3.0.rst (original)
+++ python/branches/py3k/Doc/whatsnew/3.0.rst Wed Dec 3 05:15:35 2008
@@ -4,8 +4,6 @@
.. XXX Add trademark info for Apple, Microsoft.
-.. XXX Remove duplicates; just put info in the most relevant section.
-
:Author: Guido van Rossum
:Release: |release|
:Date: |today|
@@ -132,112 +130,6 @@
:func:`print` function calls, so this is mostly a non-issue for
larger projects.
-Text Vs. Data Instead Of Unicode Vs. 8-bit
-------------------------------------------
-
-Everything you thought you knew about binary data and Unicode has
-changed:
-
-XXX HIRO
-
-* Python 3.0 uses the concepts of *text* and (binary) *data* instead
- of Unicode strings and 8-bit strings. All text is Unicode; however
- *encoded* Unicode is represented as binary data. The type used to
- hold text is :class:`str`, the type used to hold data is
- :class:`bytes`. The difference is that any attempt to mix text and
- data in Python 3.0 raises a TypeError exception, whereas if you were
- to mix Unicode and 8-bit strings in Python 2.x, you would only get
- an exception if the 8-bit string contained non-ASCII values. As a
- consequence, pretty much all code that uses Unicode, encodings or
- binary data most likely has to change. The change is for the
- better, as in the 2.x world there were numerous bugs having to do
- with mixing encoded and unencoded text.
-
-* You no longer use ``u"..."`` literals for Unicode text. However,
- you must use ``b"..."`` literals for binary data.
-
-* Files opened as text files (still the default mode for :func:`open`)
- always use an encoding to map between strings (in memory) and bytes
- (on disk). Binary files (opened with a ``b`` in the mode argument)
- always use bytes in memory. This means that if a file is opened
- using an incorrect mode or encoding, I/O will likely fail. It also
- means that even Unix users will have to specify the correct mode
- (text or binary) when opening a file. There is a platform-dependent
- default encoding, which on Unixy platforms can be set with the
- ``LANG`` environment variable (and sometimes also with some other
- platform-specific locale-related environment variables). In many
- cases, but not all, the system default is UTF-8; you should never
- count on this default. Any application reading or writing more than
- pure ASCII text should probably have a way to override the encoding.
-
-* The builtin :class:`basestring` abstract type was removed. Use
- :class:`str` instead. The :class:`str` and :class:`bytes` types
- don't have functionality enough in common to warrant a shared base
- class.
-
-* Filenames are passed to and returned from APIs as (Unicode) strings.
- This can present platform-specific problems because on some
- platforms filenames are arbitrary byte strings. (On the other hand
- on Windows, filenames are natively stored as Unicode.) As a
- work-around, most APIs (e.g. :func:`open` and many functions in the
- :mod:`os` module) that take filenames accept :class:`bytes` objects
- as well as strings, and a few APIs have a way to ask for a
- :class:`bytes` return value: :func:`os.listdir` returns a
- :class:`bytes` instance if the argument is a :class:`bytes`
- instance, and :func:`os.getcwdu` returns the current working
- directory as a :class:`bytes` instance.
-
-* Some system APIs like :data:`os.environ` and :data:`sys.argv` can
- also present problems when the bytes made available by the system is
- not interpretable using the default encoding. Setting the ``LANG``
- variable and rerunning the program is probably the best approach.
-
-* All backslashes in raw strings are interpreted literally. This
- means that ``'\U'`` and ``'\u'`` escapes in raw strings are not
- treated specially.
-
-XXX Deal with dupes below
-
-* There is only one text string type; its name is :class:`str` but its
- behavior and implementation are like :class:`unicode` in 2.x.
-
-* The :class:`basestring` superclass has been removed. The ``2to3``
- tool (see below) replaces every occurrence of :class:`basestring`
- with :class:`str`.
-
-* :pep:`3137`: There is a new type, :class:`bytes`, to represent
- binary data (and encoded text, which is treated as binary data until
- it is decoded). The :class:`str` and :class:`bytes` types cannot be
- mixed; you must always explicitly convert between them, using the
- :meth:`str.encode` (str -> bytes) or :meth:`bytes.decode` (bytes ->
- str) methods.
-
-* Like :class:`str`, the :class:`bytes` type is immutable. There is a
- separate *mutable* type to hold buffered binary data,
- :class:`bytearray`. Nearly all APIs that accept :class:`bytes` also
- accept :class:`bytearray`. The mutable API is based on
- :class:`collections.MutableSequence`.
-
-* :pep:`3138`: The :func:`repr` of a string no longer escapes
- non-ASCII characters. It still escapes control characters and code
- points with non-printable status in the Unicode standard, however.
-
-* :pep:`3120`: The default source encoding is now UTF-8.
-
-* :pep:`3131`: Non-ASCII letters are now allowed in identifiers.
- (However, the standard library remains ASCII-only with the exception
- of contributor names in comments.)
-
-* :pep:`3116`: New I/O implementation. The API is nearly 100%
- backwards compatible, but completely reimplemented (currently largely
- in Python). Also, binary files use bytes instead of strings.
-
-* The :mod:`StringIO` and :mod:`cStringIO` modules are gone. Instead,
- import :class:`io.StringIO` or :class:`io.BytesIO`, for text and
- data respectively.
-
-* See also the :ref:`unicode-howto`, which was updated for Python 3.0.
-
Views And Iterators Instead Of Lists
-------------------------------------
@@ -277,12 +169,13 @@
elements must be comparable to each other. Note that this does not
apply to the ``==`` and ``!=`` operators: objects of different
uncomparable types always compare unequal to each other, and an
- object always compares equal to itself (i.e., ``x is y`` implies ``x
- = y``; this is true even for ``NaN``).
+ object always compares equal to itself (i.e., ``x is y`` implies
+ ``x == y``; this is true even for *NaN*).
-* :meth:`builtin.sorted` and :meth:`list.sort` no longer accept the *cmp*
- argument providing a comparison function. Use the *key* argument
- instead. N.B. the *key* and *reverse* arguments are now "keyword-only".
+* :meth:`builtin.sorted` and :meth:`list.sort` no longer accept the
+ *cmp* argument providing a comparison function. Use the *key*
+ argument instead. N.B. the *key* and *reverse* arguments are now
+ "keyword-only".
* The :func:`cmp` function is gone, and the :meth:`__cmp__` special
method is no longer supported. Use :meth:`__lt__` for sorting,
@@ -316,6 +209,115 @@
* Octal literals are no longer of the form ``0720``; use ``0o720``
instead.
+Text Vs. Data Instead Of Unicode Vs. 8-bit
+------------------------------------------
+
+Everything you thought you knew about binary data and Unicode has
+changed.
+
+* Python 3.0 uses the concepts of *text* and (binary) *data* instead
+ of Unicode strings and 8-bit strings. All text is Unicode; however
+ *encoded* Unicode is represented as binary data. The type used to
+ hold text is :class:`str`, the type used to hold data is
+ :class:`bytes`. The biggest difference with the 2.x situation is
+ that any attempt to mix text and data in Python 3.0 raises
+ :ext:`TypeError`, whereas if you were to mix Unicode and 8-bit
+ strings in Python 2.x, it would work if the 8-bit string happened to
+ contain only 7-bit (ASCII) bytes, but you would get
+ :ext:`UnicodeDecodeError` if it contained non-ASCII values. This
+ value-specific behavior has caused numerous sad faces over the
+ years.
+
+* As a consequence of this change in philosophy, pretty much all code
+ that uses Unicode, encodings or binary data most likely has to
+ change. The change is for the better, as in the 2.x world there
+ were numerous bugs having to do with mixing encoded and unencoded
+ text. To be prepared in Python 2.x, start using :class:`unicode`
+ for all unencoded text, and :class:`str` for binary or encoded data
+ only. Then the ``2to3`` tool will do most of the work for you.
+
+* You can no longer use ``u"..."`` literals for Unicode text.
+ However, you must use ``b"..."`` literals for binary data.
+
+* As the :class:`str` and :class:`bytes` types cannot be mixed, you
+ must always explicitly convert between them. Use :meth:`str.encode`
+ to go from :class:`str` to :class:`bytes`, and :meth:`bytes.decode`
+ to go from :class:`bytes` to :class:`str`. You can also use
+ ``bytes(s, encoding=...)`` and ``str(b, encoding=...)``,
+ respectively.
+
+* Like :class:`str`, the :class:`bytes` type is immutable. There is a
+ separate *mutable* type to hold buffered binary data,
+ :class:`bytearray`. Nearly all APIs that accept :class:`bytes` also
+ accept :class:`bytearray`. The mutable API is based on
+ :class:`collections.MutableSequence`.
+
+* All backslashes in raw string literals are interpreted literally.
+ This means that ``'\U'`` and ``'\u'`` escapes in raw strings are not
+ treated specially. For example, ``r'\u20ac'`` is a string of 6
+ characters in Python 3.0, whereas in 2.6, ``ur'\u20ac'`` was the
+ single "euro" character. (Of course, this change only affects raw
+ string literals; the euro character is ``'\u20ac'`` in Python 3.0.)
+
+* The builtin :class:`basestring` abstract type was removed. Use
+ :class:`str` instead. The :class:`str` and :class:`bytes` types
+ don't have functionality enough in common to warrant a shared base
+ class. The ``2to3`` tool (see below) replaces every occurrence of
+ :class:`basestring` with :class:`str`.
+
+* Files opened as text files (still the default mode for :func:`open`)
+ always use an encoding to map between strings (in memory) and bytes
+ (on disk). Binary files (opened with a ``b`` in the mode argument)
+ always use bytes in memory. This means that if a file is opened
+ using an incorrect mode or encoding, I/O will likely fail loudly,
+ instead of silently producing incorrect data. It also means that
+ even Unix users will have to specify the correct mode (text or
+ binary) when opening a file. There is a platform-dependent default
+ encoding, which on Unixy platforms can be set with the ``LANG``
+ environment variable (and sometimes also with some other
+ platform-specific locale-related environment variables). In many
+ cases, but not all, the system default is UTF-8; you should never
+ count on this default. Any application reading or writing more than
+ pure ASCII text should probably have a way to override the encoding.
+ There is no longer any need for using the encoding-aware streams
+ in the :mod:`codecs` module.
+
+* Filenames are passed to and returned from APIs as (Unicode) strings.
+ This can present platform-specific problems because on some
+ platforms filenames are arbitrary byte strings. (On the other hand,
+ on Windows filenames are natively stored as Unicode.) As a
+ work-around, most APIs (e.g. :func:`open` and many functions in the
+ :mod:`os` module) that take filenames accept :class:`bytes` objects
+ as well as strings, and a few APIs have a way to ask for a
+ :class:`bytes` return value. Thus, :func:`os.listdir` returns a
+ list of :class:`bytes` instances if the argument is a :class:`bytes`
+ instance, and :func:`os.getcwdu` returns the current working
+ directory as a :class:`bytes` instance. Note that when
+ :func:`os.listdir` returns a list of strings, filenames that
+ cannot be decoded properly are omitted rather than raising
+ :exc:`UnicodeError`.
+
+* Some system APIs like :data:`os.environ` and :data:`sys.argv` can
+ also present problems when the bytes made available by the system is
+ not interpretable using the default encoding. Setting the ``LANG``
+ variable and rerunning the program is probably the best approach.
+
+* :pep:`3138`: The :func:`repr` of a string no longer escapes
+ non-ASCII characters. It still escapes control characters and code
+ points with non-printable status in the Unicode standard, however.
+
+* :pep:`3120`: The default source encoding is now UTF-8.
+
+* :pep:`3131`: Non-ASCII letters are now allowed in identifiers.
+ (However, the standard library remains ASCII-only with the exception
+ of contributor names in comments.)
+
+* The :mod:`StringIO` and :mod:`cStringIO` modules are gone. Instead,
+ import the :mod:`io` module and use :class:`io.StringIO` or
+ :class:`io.BytesIO` for text and data respectively.
+
+* See also the :ref:`unicode-howto`, which was updated for Python 3.0.
+
Overview Of Syntax Changes
==========================
@@ -341,8 +343,8 @@
* Keyword arguments are allowed after the list of base classes in a
class definition. This is used by the new convention for specifying
- a metaclass (see :pep:`3115`), but can be used for other purposes as
- well, as long as the metaclass supports it.
+ a metaclass (see next section), but can be used for other purposes
+ as well, as long as the metaclass supports it.
* :pep:`3104`: :keyword:`nonlocal` statement. Using ``nonlocal x``
you can now assign directly to a variable in an outer (but
@@ -376,8 +378,8 @@
Changed Syntax
--------------
-* New :keyword:`raise` statement syntax: ``raise [expr [from expr]]``.
- Also note that string exceptions are no longer legal (:pep:`0352`).
+* :pep:`3109` and :pep:`3134`: new :keyword:`raise` statement syntax:
+ ``raise [expr [from expr]]``. See below.
* :keyword:`as` and :keyword:`with` are now reserved words. (Since
2.6, actually.)
@@ -389,6 +391,22 @@
* Change from :keyword:`except` *exc*, *var* to
:keyword:`except` *exc* :keyword:`as` *var*. See :pep:`3110`.
+* :pep:`3115`: New Metaclass Syntax. Instead of::
+
+ class C:
+ __metaclass__ = M
+ ...
+
+ you must now use::
+
+ class C(metaclass=M):
+ ...
+
+ The module-global :data:`__metaclass__` variable is no longer
+ supported. (It was a crutch to make it easier to default to
+ new-style classes without deriving every class from
+ :class:`object`.)
+
* List comprehensions no longer support the syntactic form
``[... for var in item1, item2, ...]``. Use
``[... for var in (item1, item2, ...)]`` instead.
@@ -430,6 +448,8 @@
not starting with ``.`` are always interpreted as absolute imports.
(:pep:`0328`)
+* Classic classes are gone.
+
Changes Already Present In Python 2.6
=====================================
@@ -551,9 +571,10 @@
considered implementation details of the pure Python versions.
Users should always import the standard version, which attempts to
import the accelerated version and falls back to the pure Python
- version. The :mod:`pickle` module received this treatment. The
- :mod:`profile` module is on the list for 3.1. The :mod:`StringIO`
- module has been turned into a class in the :mod:`io` module.
+ version. The :mod:`pickle` / :mod:`cPickle` pair received this
+ treatment. The :mod:`profile` module is on the list for 3.1. The
+ :mod:`StringIO` module has been turned into a class in the :mod:`io`
+ module.
* Some related modules have been grouped into packages, and usually
the submodule names have been simplified. The resulting new
@@ -579,7 +600,8 @@
* :mod:`xmlrpc` (:mod:`xmlrpclib`, :mod:`DocXMLRPCServer`,
:mod:`SimpleXMLRPCServer`).
-Some other library changes (not covered by :pep:`3108`):
+Some other changes to standard library moduled, not covered by
+:pep:`3108`:
* Killed :mod:`sets`. Use the builtin :func:`set` function.
@@ -601,6 +623,28 @@
* Cleanup of the :mod:`random` module: removed the :func:`jumpahead` API.
+* The :mod:`new` module is gone.
+
+* The functions :func:`os.tmpnam`, :func:`os.tempnam` and
+ :func:`os.tmpfile` have been removed in favor of the :mod:`tempfile`
+ module.
+
+* The :mod:`tokenize` module has been changed to work with bytes. The
+ main entry point is now :func:`tokenize.tokenize`, instead of
+ generate_tokens.
+
+* :data:`string.letters` and its friends (:data:`string.lowercase` and
+ :data:`string.uppercase`) are gone. Use
+ :data:`string.ascii_letters` etc. instead. (The reason for the
+ removal is that :data:string.letters` and friends had
+ locale-specific behavior, which is a bad idea for such
+ attractively-named global "constants".)
+
+* Renamed module :mod:`__builtin__` to :mod:`builtins` (removing the
+ underscores, adding an 's'). The :data:`__builtins__` variable
+ found in most global namespaces is unchanged. To modify a builtin,
+ you should use :mod:`builtins`, not :data:`__builtins__`!
+
:pep:`3101`: A New Approach To String Formatting
================================================
@@ -612,81 +656,86 @@
scoop.
-:pep:`3106`: Revamping dict :meth:`dict.keys`, :meth:`dict.items` and :meth:`dict.values`
-=========================================================================================
-
-.. XXX expand this (but note that the "pitfalls" section currently has
-.. XXX more detail :-)
-
-* The :meth:`dict.iterkeys`, :meth:`dict.itervalues` and :meth:`dict.iteritems`
- methods have been removed.
-
-* :meth:`dict.keys`, :meth:`dict.values` and :meth:`dict.items` return objects
- with set behavior that reference the underlying dict; these are often
- referred to as *dictionary views*.
-
+Changes To Exceptions
+=====================
-Exception Stuff
-===============
+The APIs for raising and catching exception have been cleaned up and
+new powerful features added:
* :pep:`0352`: All exceptions must be derived (directly or indirectly)
from :exc:`BaseException`. This is the root of the exception
- hierarchy. Most exceptions should actually be derived from
- :exc:`Exception`. This is not a new recommendation, but the
+ hierarchy. This is not new as a recommendation, but the
*requirement* to inherit from :exc:`BaseException` is new. (Python
2.6 still allowed classic classes to be raised, and placed no
- restriction on what you can catch.)
-
-* :exc:`StandardError` was removed (in 2.6, actually).
-
-* Dropping sequence behavior (slicing!) and :attr:`message` attribute of
- exception instances.
-
-* :pep:`3109`: Raising exceptions. You must now use ``raise Exception(args)``
- instead of ``raise Exception, args``.
-
-* :pep:`3110`: Catching exceptions. You must now use ``except SomeException as
- identifier:`` instead of ``except Exception, identifier:``
-
-* :pep:`3134`: Exception chaining. XXX
-
-* A few exception messages are improved when Windows fails to load an extension
- module. For example, ``error code 193`` is now ``%1 is not a valid Win32
- application``. Strings now deal with non-English locales.
+ restriction on what you can catch.) As a consequence, string
+ exceptions are finally truly and utterly dead.
+* Almost all exceptions should actually derive from :exc:`Exception`;
+ :exc:`BaseException` should only be used as a base class for
+ exceptions that should only be handled at the top level, such as
+ :exc:`SystemExit` or :exc:`KeyboardInterrupt`. The recommended
+ idiom for handling all exceptions except for this latter category is
+ to use :keyword:`except` :exc:`Exception`.
+
+* :exc:`StandardError` was removed (in 2.6 already).
+
+* Exceptions no longer behave as sequences. Use the :attr:`args`
+ attribute instead.
+
+* :pep:`3109`: Raising exceptions. You must now use :keyword:`raise`
+ *Exception*(*args*) instead of :keyword:`raise` *Exception*, *args*.
+ Additionally, you can no longer explicitly specify a traceback;
+ instead, if you *have* to do this, you can assign directly to the
+ :attr:`__traceback__` attribute (see below).
+
+* :pep:`3110`: Catching exceptions. You must now use
+ *:keyword:`except` SomeException* :keyword:`as` *variable* instead
+ *of :keyword:`except` *SomeException*, variable*. Moreover, the
+ *variable* is explicitly deleted when the :keyword:`except` block
+ is left.
+
+* :pep:`3134`: Exception chaining. There are two cases: implicit
+ chaining and explicit chaining. Implicit chaining happens when an
+ exception is raised in an :keyword:`except` or :keyword:`finally`
+ handler block. This usually happens due to a bug in the handler
+ block; we call this a *secondary* exception. In this case, the
+ original exception (that was being handled) is saved as the
+ :attr:`__context__` attribute of the secondary exception.
+ Explicit chaining is invoked with this syntax::
+
+ raise SecondaryException() from primary_exception
+
+ (where *primary_exception* is any expression that produces an
+ exception object, probably an exception that was previously caught).
+ In this case, the primary exception is stored on the
+ :attr:`__cause__` attribute of the secondary exception. The
+ traceback printed when an unhandled exception occurs walks the chain
+ of :attr:`__cause__` and :attr:`__context__` attributes and prints a
+ separate traceback for each component of the chain, with the primary
+ exception at the top. (Java users may recognize this behavior. :-)
+
+* :pep:`3134`: Exception objects now store their traceback as the
+ :attr:`__traceback__` attribute. This means that an exception
+ object now contains all the information pertaining to an exception,
+ and there are fewer reasons to use :func:`sys.exc_info` (though the
+ latter is not removed).
+
+* A few exception messages are improved when Windows fails to load an
+ extension module. For example, ``error code 193`` is now ``%1 is
+ not a valid Win32 application``. Strings now deal with non-English
+ locales.
-New Class And Metaclass Stuff
-=============================
-XXX Move to new syntax section???
+Miscellaneous Other Changes
+===========================
-* Classic classes are gone.
-
-* :pep:`3115`: New Metaclass Syntax. Instead of::
-
- class C:
- __metaclass__ = M
- ...
-
- you now use::
-
- class C(metaclass=M):
- ...
-
- The module-global :data:`__metaclass__` variable is no longer supported.
- (It was a crutch to make it easier to default to new-style classes
- without deriving every class from :class:`object`.)
-
-
-Other Language Changes
-======================
-
-* Moved :func:`intern` to :func:`sys.intern`.
+Operators And Special Methods
+-----------------------------
* ``!=`` now returns the opposite of ``==``, unless ``==`` returns
- ``NotImplemented``.
+ :data:`NotImplemented`.
-* The concept of "unbound methods" was removed from the language.
+* The concept of "unbound methods" has been removed from the language.
When referencing a method as a class attribute, you now get a plain
function object.
@@ -696,27 +745,46 @@
:meth:`__delitem__`, when used as an assignment or deletion target,
respectively).
-* :pep:`3111`: :func:`raw_input` renamed to :func:`input`. That is,
- the new :func:`input` function reads a line from :data:`sys.stdin`
- and returns it with the trailing newline stripped. It raises
- :exc:`EOFError` if the input is terminated prematurely. To get the
- old behavior of :func:`input`, use ``eval(input())``.
+* :pep:`3114`: the standard :meth:`next` method has been renamed to
+ :meth:`__next__`.
+
+* The :meth:`__oct__` and :meth:`__hex__` special methods are removed
+ -- :func:`oct` and :func:`hex` use :meth:`__index__` now to convert
+ the argument to an integer.
+
+* Removed support for :attr:`__members__` and :attr:`__methods__`.
+
+* The function attributes named :attr:`func_X` have been renamed to
+ use the :data:`__X__` form, freeing up these names in the function
+ attribute namespace for user-defined attributes. To wit,
+ :attr:`func_closure`, :attr:`func_code`, :attr:`func_defaults`,
+ :attr:`func_dict`, :attr:`func_doc`, :attr:`func_globals`,
+ :attr:`func_name` were renamed to :attr:`__closure__`,
+ :attr:`__code__`, :attr:`__defaults__`, :attr:`__dict__`,
+ :attr:`__doc__`, :attr:`__globals__`, :attr:`__name__`,
+ respectively.
-* :pep:`3114`: ``.next()`` renamed to :meth:`__next__`, new builtin
- :func:`next` to call the :meth:`__next__` method on an object.
+* :meth:`__nonzero__` is now :meth:`__bool__`.
+
+Builtins
+--------
* :pep:`3135`: New :func:`super`. You can now invoke :func:`super`
- without arguments and the right class and instance will
- automatically be chosen. With arguments, its behavior is unchanged.
+ without arguments and (assuming this is in a regular instance method
+ defined inside a :keyword:`class` statement) the right class and
+ instance will automatically be chosen. With arguments, the behavior
+ of :func:`super` is unchanged.
+
+* :pep:`3111`: :func:`raw_input` was renamed to :func:`input`. That
+ is, the new :func:`input` function reads a line from
+ :data:`sys.stdin` and returns it with the trailing newline stripped.
+ It raises :exc:`EOFError` if the input is terminated prematurely.
+ To get the old behavior of :func:`input`, use ``eval(input())``.
-* :func:`zip`, :func:`map` and :func:`filter` return iterators.
+* A new builtin :func:`next` was added to call the :meth:`__next__`
+ method on an object.
-* :data:`string.letters` and its friends (:data:`string.lowercase` and
- :data:`string.uppercase`) are gone. Use
- :data:`string.ascii_letters` etc. instead. (The reason for the
- removal is that :data:string.letters` and friends had
- locale-specific behavior, which is a bad idea for such
- attractively-named global "constants".)
+* Moved :func:`intern` to :func:`sys.intern`.
* Removed: :func:`apply`. Instead of ``apply(f, args)`` use
``f(*args)``.
@@ -742,110 +810,49 @@
* Removed. :meth:`dict.has_key` -- use the :keyword:`in` operator
instead.
-* The :meth:`__oct__` and :meth:`__hex__` special methods are removed
- -- :func:`oct` and :func:`hex` use :meth:`__index__` now to convert
- the argument to an integer.
-
-* Removed support for :attr:`__members__` and :attr:`__methods__`.
-
-* Renamed the boolean conversion C-level slot and method:
- ``nb_nonzero`` is now ``nb_bool`` and :meth:`__nonzero__` is now
- :meth:`__bool__`.
-
-* Renamed module :mod:`__builtin__` to :mod:`builtins` (removing the
- underscores, adding an 's'). The :data:`__builtins__` variable
- found in most global namespaces is unchanged. To modify a builtin,
- you should use :mod:`builtins`, not :data:`__builtins__`!
-
-* Renamed function attributes :attr:`func_whatever` to
- :attr:`__whatever__`. XXX list every single one.
-
-* Removed :exc:`StandardError`.
-
-* Removed METH_OLDARGS and WITH_CYCLE_GC. XXX more.
-
.. ======================================================================
-Optimizations
--------------
-
-The net result of the 3.0 generalizations is that Python 3.0 runs the
-pystone benchmark around 10% slower than Python 2.5. Most likely the
-biggest cause is the removal of special-casing for small integers.
-There's room for improvement, but it will happen after 3.0 is
-released!
-
-.. ======================================================================
-
-
-New, Improved, And Deprecated Modules
-=====================================
-
-As usual, Python's standard library received a number of enhancements and bug
-fixes. Here's a partial list of the most notable changes, sorted alphabetically
-by module name. Consult the :file:`Misc/NEWS` file in the source tree for a more
-complete list of changes, or look through the Subversion logs for all the
-details.
-
-* The :mod:`cPickle` module is gone. Use :mod:`pickle` instead. Eventually
- we'll have a transparent accelerator module.
-
-* The :mod:`imageop` module is gone.
-
-* The :mod:`audiodev`, :mod:`Bastion`, :mod:`bsddb185`, :mod:`exceptions`,
- :mod:`linuxaudiodev`, :mod:`md5`, :mod:`MimeWriter`, :mod:`mimify`,
- :mod:`popen2`, :mod:`rexec`, :mod:`sets`, :mod:`sha`, :mod:`stringold`,
- :mod:`strop`, :mod:`sunaudiodev`, :mod:`timing`, and :mod:`xmllib` modules are
- gone.
-
-* The :mod:`bsddb` module is gone. It is being maintained externally
- with its own release schedule better mirroring that of BerkeleyDB.
- See http://www.jcea.es/programacion/pybsddb.htm.
-
-* The :mod:`new` module is gone.
-
-* The functions :func:`os.tmpnam`, :func:`os.tempnam` and :func:`os.tmpfile`
- have been removed in favor of the :mod:`tempfile` module.
-
-* The :mod:`tokenize` module has been changed to work with bytes. The main
- entry point is now :func:`tokenize.tokenize`, instead of generate_tokens.
-
-.. ======================================================================
-.. whole new modules get described in subsections here
-
-.. ======================================================================
-
-
-Build And C API Changes
+Build and C API Changes
=======================
-Changes to Python's build process and to the C API include:
+Due to time constraints, here is a *very* incomplete list of changes
+to the C API.
-* :pep:`3118`: New Buffer API. XXX
+* Support for several platforms was dropped, including but not limited
+ to Mac OS 9, BeOS, RISCOS, Irix, and Tru64.
-* :pep:`3121`: Extension Module Initialization & Finalization. XXX
+* :pep:`3118`: New Buffer API.
-* :pep:`3123`: Making :cmacro:`PyObject_HEAD` conform to standard C. XXX
+* :pep:`3121`: Extension Module Initialization & Finalization.
+
+* :pep:`3123`: Making :cmacro:`PyObject_HEAD` conform to standard C.
* No more C API support for restricted execution.
-* :cfunc:`PyNumber_Coerce`, :cfunc:`PyNumber_CoerceEx`, :cfunc:`PyMember_Get`,
- and :cfunc:`PyMember_Set` C APIs are removed.
+* :cfunc:`PyNumber_Coerce`, :cfunc:`PyNumber_CoerceEx`,
+ :cfunc:`PyMember_Get`, and :cfunc:`PyMember_Set` C APIs are removed.
* New C API :cfunc:`PyImport_ImportModuleNoBlock`, works like
- :cfunc:`PyImport_ImportModule` but won't block on the import lock (returning
- an error instead).
+ :cfunc:`PyImport_ImportModule` but won't block on the import lock
+ (returning an error instead).
-.. ======================================================================
+* Renamed the boolean conversion C-level slot and method:
+ ``nb_nonzero`` is now ``nb_bool``.
+* Removed ``METH_OLDARGS`` and ``WITH_CYCLE_GC`` from the C API.
+
+.. ======================================================================
-Port-Specific Changes
----------------------
-XXX Platform-specific changes go here.
+Performance
+===========
-* XXX BeOS, RISCOS, Irix, Tru64 support
+The net result of the 3.0 generalizations is that Python 3.0 runs the
+pystone benchmark around 10% slower than Python 2.5. Most likely the
+biggest cause is the removal of special-casing for small integers.
+There's room for improvement, but it will happen after 3.0 is
+released!
.. ======================================================================
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