Remove unnecessary `object` base class in docs (#10366).

Also add a note about inheritance from `object` being default.

Doc/includes/mp_newtype.py

@@ -12,7 +12,7 @@ import operator
 
 ##
 
-class Foo(object):
+class Foo:
     def f(self):
         print('you called Foo.f()')
     def g(self):

Doc/includes/sqlite3/adapter_point_1.py

 import sqlite3
 
-class Point(object):
+class Point:
     def __init__(self, x, y):
         self.x, self.y = x, y
 

Doc/includes/sqlite3/adapter_point_2.py

 import sqlite3
 
-class Point(object):
+class Point:
     def __init__(self, x, y):
         self.x, self.y = x, y
 

Doc/includes/sqlite3/converter_point.py

 import sqlite3
 
-class Point(object):
+class Point:
     def __init__(self, x, y):
         self.x, self.y = x, y
 

Doc/library/argparse.rst

@@ -1312,7 +1312,7 @@ already existing object, rather than the newly-created :class:`Namespace` object
 that is normally used.  This can be achieved by specifying the ``namespace=``
 keyword argument::
 
-   >>> class C(object):
+   >>> class C:
    ...     pass
    ...
    >>> c = C()

Doc/library/ctypes.rst

@@ -369,7 +369,7 @@ your own classes be used as function arguments.  :mod:`ctypes` looks for an
 :attr:`_as_parameter_` attribute and uses this as the function argument.  Of
 course, it must be one of integer, string, or bytes::
 
-   >>> class Bottles(object):
+   >>> class Bottles:
    ...     def __init__(self, number):
    ...         self._as_parameter_ = number
    ...

Doc/library/functions.rst

@@ -259,7 +259,7 @@ are always available.  They are listed here in alphabetical order.
       ['Struct', '__builtins__', '__doc__', '__file__', '__name__',
        '__package__', '_clearcache', 'calcsize', 'error', 'pack', 'pack_into',
        'unpack', 'unpack_from']
-      >>> class Foo(object):
+      >>> class Foo:
       ...     def __dir__(self):
       ...         return ["kan", "ga", "roo"]
       ...
@@ -903,7 +903,7 @@ are always available.  They are listed here in alphabetical order.
    function for setting, and *fdel* a function for del'ing, an attribute.  Typical
    use is to define a managed attribute ``x``::
 
-      class C(object):
+      class C:
           def __init__(self):
               self._x = None
 
@@ -922,7 +922,7 @@ are always available.  They are listed here in alphabetical order.
    property will copy *fget*'s docstring (if it exists).  This makes it possible to
    create read-only properties easily using :func:`property` as a :term:`decorator`::
 
-      class Parrot(object):
+      class Parrot:
           def __init__(self):
               self._voltage = 100000
 
@@ -939,7 +939,7 @@ are always available.  They are listed here in alphabetical order.
    corresponding accessor function set to the decorated function.  This is
    best explained with an example::
 
-      class C(object):
+      class C:
           def __init__(self):
               self._x = None
 
@@ -1243,7 +1243,7 @@ are always available.  They are listed here in alphabetical order.
    attribute.  For example, the following two statements create identical
    :class:`type` objects:
 
-      >>> class X(object):
+      >>> class X:
       ...     a = 1
       ...
       >>> X = type('X', (object,), dict(a=1))

Doc/library/inspect.rst

@@ -604,7 +604,7 @@ for arbitrary getset descriptors invoking these may trigger
 code execution::
 
    # example code for resolving the builtin descriptor types
-   class _foo(object):
+   class _foo:
        __slots__ = ['foo']
 
    slot_descriptor = type(_foo.foo)

Doc/library/itertools.rst

@@ -322,7 +322,7 @@ loops that truncate the stream.
 
    :func:`groupby` is equivalent to::
 
-      class groupby(object):
+      class groupby:
           # [k for k, g in groupby('AAAABBBCCDAABBB')] --> A B C D A B
           # [list(g) for k, g in groupby('AAAABBBCCD')] --> AAAA BBB CC D
           def __init__(self, iterable, key=None):

Doc/library/multiprocessing.rst

@@ -1334,7 +1334,7 @@ callables with the manager class.  For example::
 
    from multiprocessing.managers import BaseManager
 
-   class MathsClass(object):
+   class MathsClass:
        def add(self, x, y):
            return x + y
        def mul(self, x, y):

Doc/library/sqlite3.rst

@@ -710,7 +710,7 @@ Letting your object adapt itself
 This is a good approach if you write the class yourself. Let's suppose you have
 a class like this::
 
-   class Point(object):
+   class Point:
        def __init__(self, x, y):
            self.x, self.y = x, y
 

Doc/reference/compound_stmts.rst

@@ -561,7 +561,16 @@ A class definition defines a class object (see section :ref:`types`):
 A class definition is an executable statement.  The inheritance list usually
 gives a list of base classes (see :ref:`metaclasses` for more advanced uses), so
 each item in the list should evaluate to a class object which allows
-subclassing.
+subclassing.  Classes without an inheritance list inherit, by default, from the
+base class :class:`object`; hence, ::
+
+   class Foo:
+       pass
+
+is equivalent to ::
+
+   class Foo(object):
+       pass
 
 The class's suite is then executed in a new execution frame (see :ref:`naming`),
 using a newly created local namespace and the original global namespace.

Doc/reference/datamodel.rst

@@ -1987,7 +1987,7 @@ to work correctly if defined on an object's type, not in the object's instance
 dictionary.  That behaviour is the reason why the following code raises an
 exception::
 
-   >>> class C(object):
+   >>> class C:
    ...     pass
    ...
    >>> c = C()