bpo-41810: Reintroduce `types.EllipsisType`, `.NoneType` & `.NotImplementedType` (GH-22336)

closes issue 41810
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Bas van Beek 2020-09-22 17:55:34 +02:00 committed by GitHub
parent a68a2ad19c
commit 0d0e9fe2ff
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7 changed files with 54 additions and 5 deletions

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@ -19,19 +19,21 @@ A small number of constants live in the built-in namespace. They are:
.. data:: None
The sole value of the type ``NoneType``. ``None`` is frequently used to
represent the absence of a value, as when default arguments are not passed to a
function. Assignments to ``None`` are illegal and raise a :exc:`SyntaxError`.
An object frequently used to represent the absence of a value, as when
default arguments are not passed to a function. Assignments to ``None``
are illegal and raise a :exc:`SyntaxError`.
``None`` is the sole instance of the :data:`NoneType` type.
.. data:: NotImplemented
Special value which should be returned by the binary special methods
A special value which should be returned by the binary special methods
(e.g. :meth:`__eq__`, :meth:`__lt__`, :meth:`__add__`, :meth:`__rsub__`,
etc.) to indicate that the operation is not implemented with respect to
the other type; may be returned by the in-place binary special methods
(e.g. :meth:`__imul__`, :meth:`__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.
.. note::
@ -59,8 +61,9 @@ A small number of constants live in the built-in namespace. They are:
.. index:: single: ...; ellipsis literal
.. data:: Ellipsis
The same as the ellipsis literal "``...``". Special value used mostly in conjunction
The same as the ellipsis literal "``...``". Special value used mostly in conjunction
with extended slicing syntax for user-defined container data types.
``Ellipsis`` is the sole instance of the :data:`types.EllipsisType` type.
.. data:: __debug__

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@ -103,6 +103,13 @@ If you instantiate any of these types, note that signatures may vary between Pyt
Standard names are defined for the following types:
.. data:: NoneType
The type of :data:`None`.
.. versionadded:: 3.10
.. data:: FunctionType
LambdaType
@ -186,6 +193,13 @@ Standard names are defined for the following types:
.. versionadded:: 3.7
.. data:: NotImplementedType
The type of :data:`NotImplemented`.
.. versionadded:: 3.10
.. data:: MethodDescriptorType
The type of methods of some built-in data types such as :meth:`str.join`.
@ -236,6 +250,13 @@ Standard names are defined for the following types:
Defaults to ``None``. Previously the attribute was optional.
.. data:: EllipsisType
The type of :data:`Ellipsis`.
.. versionadded:: 3.10
.. class:: TracebackType(tb_next, tb_frame, tb_lasti, tb_lineno)
The type of traceback objects such as found in ``sys.exc_info()[2]``.

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@ -145,6 +145,14 @@ Add :data:`sys.orig_argv` attribute: the list of the original command line
arguments passed to the Python executable.
(Contributed by Victor Stinner in :issue:`23427`.)
types
-----
Reintroduced the :data:`types.EllipsisType`, :data:`types.NoneType`
and :data:`types.NotImplementedType` classes, providing a new set
of types readily interpretable by type checkers.
(Contributed by Bas van Beek in :issue:`41810`.)
unittest
--------

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@ -713,6 +713,16 @@ class TypesTests(unittest.TestCase):
assert repr(int | None) == "int | None"
assert repr(int | typing.GenericAlias(list, int)) == "int | list[int]"
def test_ellipsis_type(self):
self.assertIsInstance(Ellipsis, types.EllipsisType)
def test_notimplemented_type(self):
self.assertIsInstance(NotImplemented, types.NotImplementedType)
def test_none_type(self):
self.assertIsInstance(None, types.NoneType)
class MappingProxyTests(unittest.TestCase):
mappingproxy = types.MappingProxyType

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@ -296,5 +296,8 @@ def coroutine(func):
GenericAlias = type(list[int])
Union = type(int | str)
EllipsisType = type(Ellipsis)
NoneType = type(None)
NotImplementedType = type(NotImplemented)
__all__ = [n for n in globals() if n[:1] != '_']

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@ -134,6 +134,7 @@ Robin Becker
Torsten Becker
Bill Bedford
Michał Bednarski
Bas van Beek
Ian Beer
Stefan Behnel
Reimer Behrends

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@ -0,0 +1,3 @@
:data:`types.EllipsisType`, :data:`types.NotImplementedType` and
:data:`types.NoneType` have been reintroduced, providing a new set
of types readily interpretable by static type checkers.