Docs: mark up NotImplemented using the :data: role throughout the docs (#116135)

Author: erlend-aasland

Doc/library/abc.rst

@@ -101,11 +101,11 @@ a helper class :class:`ABC` to alternatively define ABCs through inheritance:
       subclass of the ABC.  (This class method is called from the
       :meth:`~class.__subclasscheck__` method of the ABC.)
 
-      This method should return ``True``, ``False`` or ``NotImplemented``.  If
+      This method should return ``True``, ``False`` or :data:`NotImplemented`.  If
       it returns ``True``, the *subclass* is considered a subclass of this ABC.
       If it returns ``False``, the *subclass* is not considered a subclass of
       this ABC, even if it would normally be one.  If it returns
-      ``NotImplemented``, the subclass check is continued with the usual
+      :data:`!NotImplemented`, the subclass check is continued with the usual
       mechanism.
 
       .. XXX explain the "usual mechanism"

Doc/library/constants.rst

@@ -33,27 +33,27 @@ A small number of constants live in the built-in namespace.  They are:
    the other type; may be returned by the in-place binary special methods
    (e.g. :meth:`~object.__imul__`, :meth:`~object.__iand__`, etc.) for the same purpose.
    It should not be evaluated in a boolean context.
-   ``NotImplemented`` is the sole instance of the :data:`types.NotImplementedType` type.
+   :data:`!NotImplemented` is the sole instance of the :data:`types.NotImplementedType` type.
 
    .. note::
 
-      When a binary (or in-place) method returns ``NotImplemented`` the
+      When a binary (or in-place) method returns :data:`!NotImplemented` the
       interpreter will try the reflected operation on the other type (or some
       other fallback, depending on the operator).  If all attempts return
-      ``NotImplemented``, the interpreter will raise an appropriate exception.
-      Incorrectly returning ``NotImplemented`` will result in a misleading
-      error message or the ``NotImplemented`` value being returned to Python code.
+      :data:`!NotImplemented`, the interpreter will raise an appropriate exception.
+      Incorrectly returning :data:`!NotImplemented` will result in a misleading
+      error message or the :data:`!NotImplemented` value being returned to Python code.
 
       See :ref:`implementing-the-arithmetic-operations` for examples.
 
    .. note::
 
-      ``NotImplementedError`` and ``NotImplemented`` are not interchangeable,
+      ``NotImplementedError`` and :data:`!NotImplemented` are not interchangeable,
       even though they have similar names and purposes.
       See :exc:`NotImplementedError` for details on when to use it.
 
    .. versionchanged:: 3.9
-      Evaluating ``NotImplemented`` in a boolean context is deprecated. While
+      Evaluating :data:`!NotImplemented` in a boolean context is deprecated. While
       it currently evaluates as true, it will emit a :exc:`DeprecationWarning`.
       It will raise a :exc:`TypeError` in a future version of Python.
 

Doc/library/exceptions.rst

@@ -335,9 +335,9 @@ The following exceptions are the exceptions that are usually raised.
 
    .. note::
 
-      ``NotImplementedError`` and ``NotImplemented`` are not interchangeable,
+      ``NotImplementedError`` and :data:`NotImplemented` are not interchangeable,
       even though they have similar names and purposes.  See
-      :data:`NotImplemented` for details on when to use it.
+      :data:`!NotImplemented` for details on when to use it.
 
 .. exception:: OSError([arg])
                OSError(errno, strerror[, filename[, winerror[, filename2]]])

Doc/library/importlib.rst

@@ -265,7 +265,7 @@ ABC hierarchy::
       when invalidating the caches of all finders on :data:`sys.meta_path`.
 
       .. versionchanged:: 3.4
-         Returns ``None`` when called instead of ``NotImplemented``.
+         Returns ``None`` when called instead of :data:`NotImplemented`.
 
 
 .. class:: PathEntryFinder

Doc/library/numbers.rst

@@ -166,7 +166,7 @@ Complex``. I'll consider ``a + b``:
 2. If ``A`` falls back to the boilerplate code, and it were to
    return a value from :meth:`~object.__add__`, we'd miss the possibility
    that ``B`` defines a more intelligent :meth:`~object.__radd__`, so the
-   boilerplate should return :const:`NotImplemented` from
+   boilerplate should return :data:`NotImplemented` from
    :meth:`!__add__`. (Or ``A`` may not implement :meth:`!__add__` at
    all.)
 3. Then ``B``'s :meth:`~object.__radd__` gets a chance. If it accepts

Doc/library/pickle.rst

@@ -377,7 +377,7 @@ The :mod:`pickle` module exports three classes, :class:`Pickler`,
       Special reducer that can be defined in :class:`Pickler` subclasses. This
       method has priority over any reducer in the :attr:`dispatch_table`.  It
       should conform to the same interface as a :meth:`~object.__reduce__` method, and
-      can optionally return ``NotImplemented`` to fallback on
+      can optionally return :data:`NotImplemented` to fallback on
       :attr:`dispatch_table`-registered reducers to pickle ``obj``.
 
       For a detailed example, see :ref:`reducer_override`.
@@ -503,7 +503,7 @@ What can be pickled and unpickled?
 The following types can be pickled:
 
 * built-in constants (``None``, ``True``, ``False``, ``Ellipsis``, and
-  ``NotImplemented``);
+  :data:`NotImplemented`);
 
 * integers, floating-point numbers, complex numbers;
 
@@ -905,7 +905,7 @@ functions and classes.
 For those cases, it is possible to subclass from the :class:`Pickler` class and
 implement a :meth:`~Pickler.reducer_override` method. This method can return an
 arbitrary reduction tuple (see :meth:`~object.__reduce__`). It can alternatively return
-``NotImplemented`` to fallback to the traditional behavior.
+:data:`NotImplemented` to fallback to the traditional behavior.
 
 If both the :attr:`~Pickler.dispatch_table` and
 :meth:`~Pickler.reducer_override` are defined, then

Doc/library/stdtypes.rst

@@ -5450,10 +5450,10 @@ The NotImplemented Object
 
 This object is returned from comparisons and binary operations when they are
 asked to operate on types they don't support. See :ref:`comparisons` for more
-information.  There is exactly one ``NotImplemented`` object.
-``type(NotImplemented)()`` produces the singleton instance.
+information.  There is exactly one :data:`NotImplemented` object.
+:code:`type(NotImplemented)()` produces the singleton instance.
 
-It is written as ``NotImplemented``.
+It is written as :code:`NotImplemented`.
 
 
 .. _typesinternal:

Doc/library/unittest.mock.rst

@@ -2143,10 +2143,10 @@ to change the default.
 
 Methods and their defaults:
 
-* ``__lt__``: ``NotImplemented``
-* ``__gt__``: ``NotImplemented``
-* ``__le__``: ``NotImplemented``
-* ``__ge__``: ``NotImplemented``
+* ``__lt__``: :data:`NotImplemented`
+* ``__gt__``: :data:`!NotImplemented`
+* ``__le__``: :data:`!NotImplemented`
+* ``__ge__``: :data:`!NotImplemented`
 * ``__int__``: ``1``
 * ``__contains__``: ``False``
 * ``__len__``: ``0``

Doc/reference/datamodel.rst

@@ -159,7 +159,7 @@ NotImplemented
 .. index:: pair: object; NotImplemented
 
 This type has a single value.  There is a single object with this value. This
-object is accessed through the built-in name ``NotImplemented``. Numeric methods
+object is accessed through the built-in name :data:`NotImplemented`. Numeric methods
 and rich comparison methods should return this value if they do not implement the
 operation for the operands provided.  (The interpreter will then try the
 reflected operation, or some other fallback, depending on the operator.)  It
@@ -170,7 +170,7 @@ See
 for more details.
 
 .. versionchanged:: 3.9
-   Evaluating ``NotImplemented`` in a boolean context is deprecated. While
+   Evaluating :data:`NotImplemented` in a boolean context is deprecated. While
    it currently evaluates as true, it will emit a :exc:`DeprecationWarning`.
    It will raise a :exc:`TypeError` in a future version of Python.
 
@@ -1787,18 +1787,18 @@ Basic customization
    ``x.__ne__(y)``, ``x>y`` calls ``x.__gt__(y)``, and ``x>=y`` calls
    ``x.__ge__(y)``.
 
-   A rich comparison method may return the singleton ``NotImplemented`` if it does
+   A rich comparison method may return the singleton :data:`NotImplemented` if it does
    not implement the operation for a given pair of arguments. By convention,
    ``False`` and ``True`` are returned for a successful comparison. However, these
    methods can return any value, so if the comparison operator is used in a Boolean
    context (e.g., in the condition of an ``if`` statement), Python will call
    :func:`bool` on the value to determine if the result is true or false.
 
    By default, ``object`` implements :meth:`__eq__` by using ``is``, returning
-   ``NotImplemented`` in the case of a false comparison:
+   :data:`NotImplemented` in the case of a false comparison:
    ``True if x is y else NotImplemented``. For :meth:`__ne__`, by default it
    delegates to :meth:`__eq__` and inverts the result unless it is
-   ``NotImplemented``.  There are no other implied relationships among the
+   :data:`!NotImplemented`.  There are no other implied relationships among the
    comparison operators or default implementations; for example, the truth of
    ``(x<y or x==y)`` does not imply ``x<=y``. To automatically generate ordering
    operations from a single root operation, see :func:`functools.total_ordering`.
@@ -2828,7 +2828,7 @@ through the object's keys; for sequences, it should iterate through the values.
    Called to implement :func:`operator.length_hint`. Should return an estimated
    length for the object (which may be greater or less than the actual length).
    The length must be an integer ``>=`` 0. The return value may also be
-   :const:`NotImplemented`, which is treated the same as if the
+   :data:`NotImplemented`, which is treated the same as if the
    ``__length_hint__`` method didn't exist at all. This method is purely an
    optimization and is never required for correctness.
 
@@ -2980,7 +2980,7 @@ left undefined.
    function is to be supported.
 
    If one of those methods does not support the operation with the supplied
-   arguments, it should return ``NotImplemented``.
+   arguments, it should return :data:`NotImplemented`.
 
 
 .. method:: object.__radd__(self, other)
@@ -3010,7 +3010,7 @@ left undefined.
    types. [#]_ For instance, to evaluate the expression ``x - y``, where *y* is
    an instance of a class that has an :meth:`__rsub__` method,
    ``type(y).__rsub__(y, x)`` is called if ``type(x).__sub__(x, y)`` returns
-   *NotImplemented*.
+   :data:`NotImplemented`.
 
    .. index:: pair: built-in function; pow
 
@@ -3503,7 +3503,7 @@ An example of an asynchronous context manager class::
    the behavior that ``None`` is not callable.
 
 .. [#] "Does not support" here means that the class has no such method, or
-   the method returns ``NotImplemented``.  Do not set the method to
+   the method returns :data:`NotImplemented`.  Do not set the method to
    ``None`` if you want to force fallback to the right operand's reflected
    method—that will instead have the opposite effect of explicitly
    *blocking* such fallback.

Doc/reference/expressions.rst

@@ -1539,7 +1539,7 @@ built-in types.
   ``x == x`` are all false, while ``x != x`` is true.  This behavior is
   compliant with IEEE 754.
 
-* ``None`` and ``NotImplemented`` are singletons.  :PEP:`8` advises that
+* ``None`` and :data:`NotImplemented` are singletons.  :PEP:`8` advises that
   comparisons for singletons should always be done with ``is`` or ``is not``,
   never the equality operators.