Update whatsnew document to use specific markup for identifiers, thus enabling cross-linking.
This commit is contained in:
Georg Brandl
parent
396ef80f0d
commit
ec17d204f9
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@ -79,7 +79,7 @@ and fast errors; it's the subtle behavioral changes in code that
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remains syntactically valid that trips people up. I'm also omitting
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changes to rarely used features.)
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* The ``print`` statement has been replaced with a ``print()`` function,
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* The ``print`` statement has been replaced with a :func:`print` function,
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with keyword arguments to replace most of the special syntax of the
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old ``print`` statement (PEP 3105). Examples::
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@ -106,9 +106,9 @@ changes to rarely used features.)
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There are <4294967296> possibilities!
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Notes about the ``print()`` function:
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Notes about the :func:`print` function:
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* The ``print()`` function doesn't support the "softspace" feature of
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* The :func:`print` function doesn't support the "softspace" feature of
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the old ``print`` statement. For example, in Python 2.x,
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``print "A\n", "B"`` would write ``"A\nB\n"``; but in Python 3.0,
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``print("A\n", "B")`` writes ``"A\n B\n"``.
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@ -118,7 +118,7 @@ changes to rarely used features.)
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``print(x)`` instead!
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* When using the ``2to3`` source-to-source conversion tool, all
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``print`` statements are autmatically converted to ``print()``
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``print`` statements are autmatically converted to :func:`print`
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function calls, so this is mostly a non-issue for larger projects.
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* Python 3.0 uses strings and bytes instead of the Unicode strings and
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@ -131,19 +131,19 @@ changes to rarely used features.)
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that if a file is opened using an incorrect mode or encoding, I/O
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will likely fail.
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* ``map()`` and ``filter()`` return iterators. A quick fix is e.g.
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* :func:`map` and :func:`filter` return iterators. A quick fix is e.g.
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``list(map(...))``, but a better fix is often to use a list
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comprehension (especially when the original code uses ``lambda``).
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Particularly tricky is ``map()`` invoked for the side effects of the
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comprehension (especially when the original code uses :keyword:`lambda`).
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Particularly tricky is :func:`map` invoked for the side effects of the
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function; the correct transformation is to use a for-loop.
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* ``dict`` methods ``.keys()``, ``.items()`` and ``.values()`` return
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views instead of lists. For example, this no longer works:
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``k = d.keys(); k.sort()``. Use ``k = sorted(d)`` instead.
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* :class:`dict` methods :meth:`dict.keys`, :meth:`dict.items` and
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:meth:`dict.values` return views instead of lists. For example, this no
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longer works: ``k = d.keys(); k.sort()``. Use ``k = sorted(d)`` instead.
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* ``1/2`` returns a float. Use ``1//2`` to get the truncating behavior.
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* The ``repr()`` of a long integer doesn't include the trailing ``L``
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* The :func:`repr` of a long integer doesn't include the trailing ``L``
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anymore, so code that unconditionally strips that character will
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chop off the last digit instead.
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@ -151,32 +151,33 @@ changes to rarely used features.)
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Strings and Bytes
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=================
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* There is only one string type; its name is ``str`` but its behavior
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and implementation are more like ``unicode`` in 2.x.
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* There is only one string type; its name is :class:`str` but its behavior and
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implementation are like :class:`unicode` in 2.x.
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* The ``basestring`` superclass has been removed. The ``2to3`` tool
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replaces every occurence of ``basestring`` with ``str``.
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* The :class:`basestring` superclass has been removed. The ``2to3`` tool
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replaces every occurence of :class:`basestring` with :class:`str`.
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* PEP 3137: There is a new type, ``bytes``, to represent binary data
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(and encoded text, which is treated as binary data until you decide
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to decode it). The ``str`` and ``bytes`` types cannot be mixed; you
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must always explicitly convert between them, using the ``.encode()``
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(str -> bytes) or ``.decode()`` (bytes -> str) methods.
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* PEP 3137: There is a new type, :class:`bytes`, to represent binary data (and
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encoded text, which is treated as binary data until you decide to decode it).
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The :class:`str` and :class:`bytes` types cannot be mixed; you must always
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explicitly convert between them, using the :meth:`str.encode` (str -> bytes)
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or :meth:`bytes.decode` (bytes -> str) methods.
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* PEP 3112: Bytes literals. E.g. b"abc".
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.. XXX add bytearray
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* PEP 3112: Bytes literals, e.g. ``b"abc"``, create :class:`bytes` instances.
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* PEP 3120: UTF-8 default source encoding.
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* PEP 3131: Non-ASCII identifiers. (However, the standard library
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remains ASCII-only with the exception of contributor names in
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comments.)
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* PEP 3131: Non-ASCII identifiers. (However, the standard library remains
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ASCII-only with the exception of contributor names in comments.)
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* PEP 3116: New I/O Implementation. The API is nearly 100% backwards
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compatible, but completely reimplemented (currently mostly in
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Python). Also, binary files use bytes instead of strings.
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compatible, but completely reimplemented (currently mostly in Python). Also,
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binary files use bytes instead of strings.
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* The ``StringIO`` and ``cStringIO`` modules are gone. Instead,
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import ``StringIO`` or ``BytesIO`` from the ``io`` module.
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* The :mod:`StringIO` and :mod:`cStringIO` modules are gone. Instead, import
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:class:`io.StringIO` or :class:`io.BytesIO`.
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PEP 3101: A New Approach to String Formatting
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@ -184,20 +185,20 @@ PEP 3101: A New Approach to String Formatting
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.. XXX expand this
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* A new system for built-in string formatting operations replaces
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the ``%`` string formatting operator.
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* A new system for built-in string formatting operations replaces the ``%``
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string formatting operator.
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PEP 3106: Revamping dict ``.keys()``, ``.items()`` and ``.values()``
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====================================================================
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PEP 3106: Revamping dict :meth:`dict.keys`, :meth:`dict.items` and :meth:`dict.values`
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======================================================================================
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.. XXX expand this
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* The ``.iterkeys()``, ``.itervalues()`` and ``.iteritems()`` methods
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have been removed.
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* The :meth:`dict.iterkeys`, :meth:`dict.itervalues` and :meth:`dict.iteritems`
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methods have been removed.
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* ``.keys()``, ``.values()`` and ``.items()`` return objects with set
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behavior that reference the underlying dict.
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* :meth:`dict.keys`, :meth:`dict.values` and :meth:`dict.items` return objects
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with set behavior that reference the underlying dict.
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PEP 3107: Function Annotations
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@ -205,33 +206,31 @@ PEP 3107: Function Annotations
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.. XXX expand this
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* A standardized way of annotating a function's parameters and return
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values.
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* A standardized way of annotating a function's parameters and return values.
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Exception Stuff
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===============
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* PEP 352: Exceptions must derive from BaseException. This is the
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root of the exception hierarchy.
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* PEP 352: Exceptions must derive from :exc:`BaseException`. This is the root
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of the exception hierarchy.
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* StandardException was removed (already in 2.6).
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* :exc:`StandardError` was removed (already in 2.6).
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* Dropping sequence behavior (slicing!) and ``.message`` attribute of
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* Dropping sequence behavior (slicing!) and :attr:`message` attribute of
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exception instances.
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* PEP 3109: Raising exceptions. You must now use ``raise
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Exception(args)`` instead of ``raise Exception, args``.
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* PEP 3109: Raising exceptions. You must now use ``raise Exception(args)``
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instead of ``raise Exception, args``.
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* PEP 3110: Catching exceptions.
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* PEP 3134: Exception chaining. (The ``__context__`` feature from the
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PEP hasn't been implemented yet in 3.0a1.)
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* PEP 3134: Exception chaining. (The :attr:`__context__` feature from the PEP
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hasn't been implemented yet in 3.0a2.)
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* A few exception messages are improved when Windows fails to load an
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extension module. For example, ``error code 193`` is now ``%1 is not
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a valid Win32 application``. Strings now deal with non-English
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locales.
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* A few exception messages are improved when Windows fails to load an extension
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module. For example, ``error code 193`` is now ``%1 is not a valid Win32
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application``. Strings now deal with non-English locales.
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New Class and Metaclass Stuff
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@ -255,101 +254,97 @@ Other Language Changes
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Here are most of the changes that Python 3.0 makes to the core Python
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language and built-in functions.
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* Removed backticks (use ``repr()`` instead).
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* Removed backticks (use :func:`repr` instead).
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* Removed ``<>`` (use ``!=`` instead).
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* ``!=`` now returns the opposite of ``==``, unless ``==`` returns
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``NotImplemented``.
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* ``as`` and ``with`` are keywords.
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* :keyword:`as` and :keyword:`with` are keywords.
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* ``True``, ``False``, and ``None`` are keywords.
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* PEP 237: ``long`` renamed to ``int``. That is, there is only one
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built-in integral type, named ``int``; but it behaves like the old
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``long`` type, with the exception that the literal suffix ``L`` is
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neither supported by the parser nor produced by ``repr()`` anymore.
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``sys.maxint`` was also removed since the int type has no maximum
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value anymore.
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* PEP 237: :class:`long` renamed to :class:`int`. That is, there is only one
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built-in integral type, named :class:`int`; but it behaves like the old
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:class:`long` type, with the exception that the literal suffix ``L`` is
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neither supported by the parser nor produced by :func:`repr` anymore.
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:data:`sys.maxint` was also removed since the int type has no maximum value
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anymore.
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* PEP 238: int division returns a float.
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* The ordering operators behave differently: for example, ``x < y``
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where ``x`` and ``y`` have incompatible types raises ``TypeError``
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instead of returning a pseudo-random boolean.
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* The ordering operators behave differently: for example, ``x < y`` where ``x``
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and ``y`` have incompatible types raises :exc:`TypeError` instead of returning
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a pseudo-random boolean.
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* ``__getslice__()`` and friends killed. The syntax ``a[i:j]`` now
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translates to ``a.__getitem__(slice(i, j))`` (or ``__setitem__``
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or ``__delitem__``, depending on context).
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* :meth:`__getslice__` and friends killed. The syntax ``a[i:j]`` now translates
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to ``a.__getitem__(slice(i, j))`` (or :meth:`__setitem__` or
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:meth:`__delitem__`, depending on context).
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* PEP 3102: Keyword-only arguments. Named parameters occurring after
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``*args`` in the parameter list *must* be specified using keyword
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syntax in the call. You can also use a bare ``*`` in the parameter
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list to indicate that you don't accept a variable-length argument
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list, but you do have keyword-only arguments.
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* PEP 3102: Keyword-only arguments. Named parameters occurring after ``*args``
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in the parameter list *must* be specified using keyword syntax in the call.
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You can also use a bare ``*`` in the parameter list to indicate that you don't
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accept a variable-length argument list, but you do have keyword-only
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arguments.
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* PEP 3104: ``nonlocal`` statement. Using ``nonlocal x`` you can now
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* PEP 3104: :keyword:`nonlocal` statement. Using ``nonlocal x`` you can now
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assign directly to a variable in an outer (but non-global) scope.
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* PEP 3111: ``raw_input()`` renamed to ``input()``. That is, the new
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``input()`` function reads a line from ``sys.stdin`` and returns it
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with the trailing newline stripped. It raises ``EOFError`` if the
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input is terminated prematurely. To get the old behavior of
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``input()``, use ``eval(input())``.
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* PEP 3111: :func:`raw_input` renamed to :func:`input`. That is, the new
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:func:`input` function reads a line from :data:`sys.stdin` and returns it with
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the trailing newline stripped. It raises :exc:`EOFError` if the input is
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terminated prematurely. To get the old behavior of :func:`input`, use
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``eval(input())``.
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* ``xrange()`` renamed to ``range()``.
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* :func:`xrange` renamed to :func:`range`.
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* PEP 3113: Tuple parameter unpacking removed. You can no longer write
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``def foo(a, (b, c)): ...``. Use ``def foo(a, b_c): b, c = b_c``
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instead.
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* PEP 3113: Tuple parameter unpacking removed. You can no longer write ``def
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foo(a, (b, c)): ...``. Use ``def foo(a, b_c): b, c = b_c`` instead.
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* PEP 3114: ``.next()`` renamed to ``.__next__()``, new builtin
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``next()`` to call the ``__next__()`` method on an object.
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* PEP 3114: ``.next()`` renamed to :meth:`__next__`, new builtin :func:`next` to
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call the :meth:`__next__` method on an object.
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* PEP 3127: New octal literals; binary literals and ``bin()``.
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Instead of ``0666``, you write ``0o666``. The oct() function is
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modified accordingly. Also, ``0b1010`` equals 10, and ``bin(10)``
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returns ``"0b1010"``. ``0666`` is now a ``SyntaxError``.
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* PEP 3127: New octal literals; binary literals and :func:`bin`. Instead of
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``0666``, you write ``0o666``. The :func:`oct` function is modified
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accordingly. Also, ``0b1010`` equals 10, and ``bin(10)`` returns
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``"0b1010"``. ``0666`` is now a :exc:`SyntaxError`.
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* PEP 3132: Extended Iterable Unpacking. You can now write things
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like ``a, b, *rest = some_sequence``. And even ``*rest, a =
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stuff``. The ``rest`` object is always a list; the right-hand
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side may be any iterable.
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* PEP 3132: Extended Iterable Unpacking. You can now write things like ``a, b,
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*rest = some_sequence``. And even ``*rest, a = stuff``. The ``rest`` object
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is always a list; the right-hand side may be any iterable.
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* PEP 3135: New ``super()``. You can now invoke ``super()`` without
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arguments and the right class and instance will automatically be
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chosen. With arguments, its behavior is unchanged.
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* PEP 3135: New :func:`super`. You can now invoke :func:`super` without
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arguments and the right class and instance will automatically be chosen. With
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arguments, its behavior is unchanged.
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* ``zip()``, ``map()`` and ``filter()`` return iterators.
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* :func:`zip`, :func:`map` and :func:`filter` return iterators.
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* ``string.letters`` and its friends (``.lowercase`` and
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``.uppercase``) are gone. Use ``string.ascii_letters``
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* :data:`string.letters` and its friends (:data:`string.lowercase` and
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:data:`string.uppercase`) are gone. Use :data:`string.ascii_letters`
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etc. instead.
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* Removed: ``apply()``, ``callable()``, ``coerce()``, ``execfile()``,
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``file()``, ``reduce()``, ``reload()``.
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* Removed: :func:`apply`, :func:`callable`, :func:`coerce`, :func:`execfile`,
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:func:`file`, :func:`reduce`, :func:`reload`.
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* Removed: ``dict.has_key()``.
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* Removed: :meth:`dict.has_key`.
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* ``exec`` is now a function.
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* :func:`exec` is now a function.
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* There is a new free format floating point representation, which is
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based on "Floating-Point Printer Sample Code", by Robert G. Burger.
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``repr(11./5)`` now returns ``2.2`` instead of ``2.2000000000000002``.
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* There is a new free format floating point representation, which is based on
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"Floating-Point Printer Sample Code", by Robert G. Burger. ``repr(11./5)``
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now returns ``2.2`` instead of ``2.2000000000000002``.
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* The ``__oct__()`` and ``__hex__()`` special methods are removed --
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``oct()`` and ``hex()`` use ``__index__()`` now to convert the
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argument to an integer.
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* The :meth:`__oct__` and :meth:`__hex__` special methods are removed --
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:func:`oct` and :func:`hex` use :meth:`__index__` now to convert the argument
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to an integer.
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* There is now a ``bin()`` builtin function.
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* Support is removed for :attr:`__members__` and :attr:`__methods__`.
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* Support is removed for ``__members__`` and ``__methods__``.
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* Renamed the boolean conversion C-level slot and method: ``nb_nonzero`` is now
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``nb_bool`` and :meth:`__nonzero__` is now :meth:`__bool__`.
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* ``nb_nonzero`` is now ``nb_bool`` and ``__nonzero__`` is now
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``__bool__``.
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* Removed ``sys.maxint``. Use ``sys.maxsize``.
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* Removed :data:`sys.maxint`. Use :data:`sys.maxsize`.
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.. ======================================================================
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@ -360,10 +355,10 @@ Optimizations
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* Detailed changes are listed here.
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The net result of the 3.0 generalizations is that Python 3.0 runs the
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pystone benchmark around 33% slower than Python 2.5. There's room for
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improvement; we expect to be optimizing string and integer operations
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significantly before the final 3.0 release!
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The net result of the 3.0 generalizations is that Python 3.0 runs the pystone
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benchmark around 33% slower than Python 2.5. There's room for improvement; we
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expect to be optimizing string and integer operations significantly before the
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final 3.0 release!
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.. ======================================================================
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@ -371,26 +366,27 @@ significantly before the final 3.0 release!
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New, Improved, and Deprecated Modules
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=====================================
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As usual, Python's standard library received a number of enhancements
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and bug fixes. Here's a partial list of the most notable changes,
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sorted alphabetically by module name. Consult the :file:`Misc/NEWS`
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file in the source tree for a more complete list of changes, or look
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through the Subversion logs for all the details.
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As usual, Python's standard library received a number of enhancements and bug
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fixes. Here's a partial list of the most notable changes, sorted alphabetically
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by module name. Consult the :file:`Misc/NEWS` file in the source tree for a more
|
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complete list of changes, or look through the Subversion logs for all the
|
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details.
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* The ``cPickle`` module is gone. Use ``pickle`` instead. Eventually
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* The :mod:`cPickle` module is gone. Use :mod:`pickle` instead. Eventually
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we'll have a transparent accelerator module.
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* The ``imageop`` module is gone.
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* The :mod:`imageop` module is gone.
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* The ``audiodev``, ``Bastion``, ``bsddb185``, ``exceptions``,
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``linuxaudiodev``, ``md5``, ``MimeWriter``, ``mimify``, ``popen2``,
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``rexec``, ``sets``, ``sha``, ``stringold``, ``strop``, ``sunaudiodev``,
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``timing``, and ``xmllib`` modules are gone.
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* The :mod:`audiodev`, :mod:`Bastion`, :mod:`bsddb185`, :mod:`exceptions`,
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:mod:`linuxaudiodev`, :mod:`md5`, :mod:`MimeWriter`, :mod:`mimify`,
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:mod:`popen2`, :mod:`rexec`, :mod:`sets`, :mod:`sha`, :mod:`stringold`,
|
||||
:mod:`strop`, :mod:`sunaudiodev`, :mod:`timing`, and :mod:`xmllib` modules are
|
||||
gone.
|
||||
|
||||
* The ``new`` module is gone.
|
||||
* The :mod:`new` module is gone.
|
||||
|
||||
* The methods ``os.tmpnam()``, ``os.tempnam()`` and ``os.tmpfile()`` have
|
||||
been removed in favor of the ``tempfile`` module.
|
||||
* The functions :func:`os.tmpnam`, :func:`os.tempnam` and :func:`os.tmpfile`
|
||||
have been removed in favor of the :mod:`tempfile` module.
|
||||
|
||||
.. ======================================================================
|
||||
.. whole new modules get described in subsections here
|
||||
|
|
@ -407,15 +403,15 @@ Changes to Python's build process and to the C API include:
|
|||
|
||||
* PEP 3121: Extension Module Initialization & Finalization.
|
||||
|
||||
* PEP 3123: Making ``PyObject_HEAD`` conform to standard C.
|
||||
* PEP 3123: Making :cmacro:`PyObject_HEAD` conform to standard C.
|
||||
|
||||
* No more C API support for restricted execution.
|
||||
|
||||
* ``PyNumber_Coerce()``, ``PyNumber_CoerceEx()``, ``PyMember_Get``,
|
||||
and ``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 ``PyImport_ImportModuleNoBlock()``, works like
|
||||
``PyImport_ImportModule()`` but won't block on the import lock (returning
|
||||
* New C API :cfunc:`PyImport_ImportModuleNoBlock`, works like
|
||||
:cfunc:`PyImport_ImportModule` but won't block on the import lock (returning
|
||||
an error instead).
|
||||
|
||||
.. ======================================================================
|
||||
|
|
|
|||
Loading…
Reference in New Issue