Remove references to __cmp__.

birkenfeld · birkenfeld · commit 05f5ab7ee39b · 2008-09-24T09:11:47.000Z
diff --git a/Doc/glossary.rst b/Doc/glossary.rst
@@ -246,8 +246,8 @@ Glossary
    hashable
       An object is *hashable* if it has a hash value which never changes during
       its lifetime (it needs a :meth:`__hash__` method), and can be compared to
-      other objects (it needs an :meth:`__eq__` or :meth:`__cmp__` method).
-      Hashable objects which compare equal must have the same hash value.
+      other objects (it needs an :meth:`__eq__` method).  Hashable objects which
+      compare equal must have the same hash value.
 
       Hashability makes an object usable as a dictionary key and a set member,
       because these data structures use the hash value internally.
diff --git a/Doc/library/decimal.rst b/Doc/library/decimal.rst
@@ -375,15 +375,14 @@ Decimal objects
 
    .. method:: compare(other[, context])
 
-      Compare the values of two Decimal instances.  This operation behaves in
-      the same way as the usual comparison method :meth:`__cmp__`, except that
-      :meth:`compare` returns a Decimal instance rather than an integer, and if
-      either operand is a NaN then the result is a NaN::
-
-         a or b is a NaN ==> Decimal('NaN')
-         a < b           ==> Decimal('-1')
-         a == b          ==> Decimal('0')
-         a > b           ==> Decimal('1')
+      Compare the values of two Decimal instances.  :meth:`compare` returns a
+      Decimal instance, and if either operand is a NaN then the result is a
+      NaN::
+
+         a or b is a NaN  ==> Decimal('NaN')
+         a < b            ==> Decimal('-1')
+         a == b           ==> Decimal('0')
+         a > b            ==> Decimal('1')
 
    .. method:: compare_signal(other[, context])
 
diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
@@ -173,23 +173,21 @@ any operand is a complex number, the objects are of different types that cannot
 be compared, or other cases where there is no defined ordering.
 
 .. index:: 
-   single: __cmp__() (instance method)
    single: __eq__() (instance method)
    single: __ne__() (instance method)
    single: __lt__() (instance method)
    single: __le__() (instance method)
    single: __gt__() (instance method)
    single: __ge__() (instance method)
 
-Instances of a class normally compare as non-equal unless the class defines the
-:meth:`__eq__` or :meth:`__cmp__` method.
+Non-identical instances of a class normally compare as non-equal unless the
+class defines the :meth:`__eq__` method.
 
 Instances of a class cannot be ordered with respect to other instances of the
 same class, or other types of object, unless the class defines enough of the
-methods :meth:`__cmp__`, :meth:`__lt__`, :meth:`__le__`, :meth:`__gt__`, and
-:meth:`__ge__` (in general, either :meth:`__cmp__` or both :meth:`__lt__` and
-:meth:`__eq__` are sufficient, if you want the conventional meanings of the
-comparison operators).
+methods :meth:`__lt__`, :meth:`__le__`, :meth:`__gt__`, and :meth:`__ge__` (in
+general, :meth:`__lt__` and :meth:`__eq__` are sufficient, if you want the
+conventional meanings of the comparison operators).
 
 The behavior of the :keyword:`is` and :keyword:`is not` operators cannot be
 customized; also they can be applied to any two objects and never raise an
@@ -1642,8 +1640,7 @@ The constructors for both classes work the same:
    The subset and equality comparisons do not generalize to a complete ordering
    function.  For example, any two disjoint sets are not equal and are not
    subsets of each other, so *all* of the following return ``False``: ``a<b``,
-   ``a==b``, or ``a>b``. Accordingly, sets do not implement the :meth:`__cmp__`
-   method.
+   ``a==b``, or ``a>b``.
 
    Since sets only define partial ordering (subset relationships), the output of
    the :meth:`list.sort` method is undefined for lists of sets.
diff --git a/Doc/library/xmlrpc.client.rst b/Doc/library/xmlrpc.client.rst
@@ -210,7 +210,7 @@ use by the marshalling/unmarshalling code:
    Write the XML-RPC encoding of this :class:`DateTime` item to the *out* stream
    object.
 
-It also supports certain of Python's built-in operators through  :meth:`__cmp__`
+It also supports certain of Python's built-in operators through rich comparison
 and :meth:`__repr__` methods.
 
 A working example follows. The server code::
@@ -273,8 +273,8 @@ internal use by the marshalling/unmarshalling code:
    which was the de facto standard base64 specification when the
    XML-RPC spec was written.
 
-It also supports certain of Python's built-in operators through a
-:meth:`__cmp__` method.
+It also supports certain of Python's built-in operators through :meth:`__eq__`
+and :meth:`__ne__` methods.
 
 Example usage of the binary objects.  We're going to transfer an image over
 XMLRPC::
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
@@ -1168,8 +1168,7 @@ Basic customization
    .. index::
       single: comparisons
 
-   These are the so-called "rich comparison" methods, and are called for comparison
-   operators in preference to :meth:`__cmp__` below. The correspondence between
+   These are the so-called "rich comparison" methods. The correspondence between
    operator symbols and method names is as follows: ``x<y`` calls ``x.__lt__(y)``,
    ``x<=y`` calls ``x.__le__(y)``, ``x==y`` calls ``x.__eq__(y)``, ``x!=y`` calls
    ``x.__ne__(y)``, ``x>y`` calls ``x.__gt__(y)``, and ``x>=y`` calls
@@ -1198,28 +1197,11 @@ Basic customization
    Arguments to rich comparison methods are never coerced.
 
 
-.. method:: object.__cmp__(self, other)
-
-   .. index::
-      builtin: cmp
-      single: comparisons
-
-   Called by comparison operations if rich comparison (see above) is not
-   defined.  Should return a negative integer if ``self < other``, zero if
-   ``self == other``, a positive integer if ``self > other``.  If no
-   :meth:`__cmp__`, :meth:`__eq__` or :meth:`__ne__` operation is defined, class
-   instances are compared by object identity ("address").  See also the
-   description of :meth:`__hash__` for some important notes on creating
-   :term:`hashable` objects which support custom comparison operations and are
-   usable as dictionary keys.
-
-
 .. method:: object.__hash__(self)
 
    .. index::
       object: dictionary
       builtin: hash
-      single: __cmp__() (object method)
 
    Called for the key object for dictionary operations, and by the built-in
    function :func:`hash`.  Should return an integer usable as a hash value
@@ -1228,37 +1210,35 @@ Basic customization
    (e.g., using exclusive or) the hash values for the components of the object that
    also play a part in comparison of objects.
 
-   If a class does not define a :meth:`__cmp__` or :meth:`__eq__` method it
-   should not define a :meth:`__hash__` operation either; if it defines
-   :meth:`__cmp__` or :meth:`__eq__` but not :meth:`__hash__`, its instances
-   will not be usable as dictionary keys.  If a class defines mutable objects
-   and implements a :meth:`__cmp__` or :meth:`__eq__` method, it should not
-   implement :meth:`__hash__`, since the dictionary implementation requires that
-   a key's hash value is immutable (if the object's hash value changes, it will
-   be in the wrong hash bucket).
+   If a class does not define an :meth:`__eq__` method it should not define a
+   :meth:`__hash__` operation either; if it defines :meth:`__eq__` but not
+   :meth:`__hash__`, its instances will not be usable as dictionary keys.  If a
+   class defines mutable objects and implements an :meth:`__eq__` method, it
+   should not implement :meth:`__hash__`, since the dictionary implementation
+   requires that a key's hash value is immutable (if the object's hash value
+   changes, it will be in the wrong hash bucket).
 
-   User-defined classes have :meth:`__cmp__` and :meth:`__hash__` methods
+   User-defined classes have :meth:`__eq__` and :meth:`__hash__` methods
    by default; with them, all objects compare unequal (except with themselves)
    and ``x.__hash__()`` returns ``id(x)``.
 
    Classes which inherit a :meth:`__hash__` method from a parent class but
-   change the meaning of :meth:`__cmp__` or :meth:`__eq__` such that the hash
-   value returned is no longer appropriate (e.g. by switching to a value-based
-   concept of equality instead of the default identity based equality) can
-   explicitly flag themselves as being unhashable by setting
-   ``__hash__ = None`` in the class definition. Doing so means that not only
-   will instances of the class raise an appropriate :exc:`TypeError` when
-   a program attempts to retrieve their hash value, but they will also be
-   correctly identified as unhashable when checking
-   ``isinstance(obj, collections.Hashable)`` (unlike classes which define
-   their own :meth:`__hash__` to explicitly raise :exc:`TypeError`).
-
-   If a class that overrrides :meth:`__cmp__` or :meth:`__eq__` needs to
-   retain the implementation of :meth:`__hash__` from a parent class,
-   the interpreter must be told this explicitly by setting
-   ``__hash__ = <ParentClass>.__hash__``. Otherwise the inheritance of
-   :meth:`__hash__` will be blocked, just as if :attr:`__hash__` had been
-   explicitly set to :const:`None`.
+   change the meaning of :meth:`__eq__` such that the hash value returned is no
+   longer appropriate (e.g. by switching to a value-based concept of equality
+   instead of the default identity based equality) can explicitly flag
+   themselves as being unhashable by setting ``__hash__ = None`` in the class
+   definition. Doing so means that not only will instances of the class raise an
+   appropriate :exc:`TypeError` when a program attempts to retrieve their hash
+   value, but they will also be correctly identified as unhashable when checking
+   ``isinstance(obj, collections.Hashable)`` (unlike classes which define their
+   own :meth:`__hash__` to explicitly raise :exc:`TypeError`).
+
+   If a class that overrrides :meth:`__eq__` needs to retain the implementation
+   of :meth:`__hash__` from a parent class, the interpreter must be told this
+   explicitly by setting ``__hash__ = <ParentClass>.__hash__``. Otherwise the
+   inheritance of :meth:`__hash__` will be blocked, just as if :attr:`__hash__`
+   had been explicitly set to :const:`None`.
+
 
 .. method:: object.__bool__(self)
 
