bpo-43345: Enhance TypedDict documentation. (#24668)

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Paul Bryan 2021-02-27 23:02:14 -08:00 committed by GitHub
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@ -1247,26 +1247,28 @@ These are not used in annotations. They are building blocks for declaring types.
assert Point2D(x=1, y=2, label='first') == dict(x=1, y=2, label='first')
The type info for introspection can be accessed via ``Point2D.__annotations__``
and ``Point2D.__total__``. To allow using this feature with older versions
of Python that do not support :pep:`526`, ``TypedDict`` supports two additional
equivalent syntactic forms::
The type info for introspection can be accessed via ``Point2D.__annotations__``,
``Point2D.__total__``, ``Point2D.__required_keys__``, and
``Point2D.__optional_keys__``.
To allow using this feature with older versions of Python that do not
support :pep:`526`, ``TypedDict`` supports two additional equivalent
syntactic forms::
Point2D = TypedDict('Point2D', x=int, y=int, label=str)
Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str})
By default, all keys must be present in a TypedDict. It is possible
to override this by specifying totality.
By default, all keys must be present in a ``TypedDict``. It is possible to
override this by specifying totality.
Usage::
class point2D(TypedDict, total=False):
class Point2D(TypedDict, total=False):
x: int
y: int
This means that a point2D TypedDict can have any of the keys omitted. A type
checker is only expected to support a literal False or True as the value of
the total argument. True is the default, and makes all items defined in the
class body be required.
This means that a ``Point2D`` ``TypedDict`` can have any of the keys
omitted. A type checker is only expected to support a literal ``False`` or
``True`` as the value of the ``total`` argument. ``True`` is the default,
and makes all items defined in the class body required.
See :pep:`589` for more examples and detailed rules of using ``TypedDict``.
@ -1980,4 +1982,3 @@ Constant
(see :pep:`563`).
.. versionadded:: 3.5.2