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author | Guido van Rossum <guido@python.org> | 2016-09-11 01:49:14 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 2016-09-11 01:49:14 (GMT) |
commit | 1816dfe65f5cba50331342d153e99482b18b2d4e (patch) | |
tree | d7f58dd05229756a6015fd05932d7fc9e63e6a94 | |
parent | cc66a6528d0f756a23da29e31b2e6332def03a18 (diff) | |
download | cpython-1816dfe65f5cba50331342d153e99482b18b2d4e.zip cpython-1816dfe65f5cba50331342d153e99482b18b2d4e.tar.gz cpython-1816dfe65f5cba50331342d153e99482b18b2d4e.tar.bz2 |
Issue #28073: Improve wording around None. Michael Lee.
-rw-r--r-- | Doc/library/typing.rst | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/Doc/library/typing.rst b/Doc/library/typing.rst index 83a8dcf..640255a 100644 --- a/Doc/library/typing.rst +++ b/Doc/library/typing.rst @@ -59,6 +59,9 @@ Type aliases are useful for simplifying complex type signatures. For example:: servers: List[Tuple[Tuple[str, int], Dict[str, str]]]) -> None: ... +Note that ``None`` as a type hint is a special case and is replaced by +``type(None)``. + NewType ------- @@ -148,7 +151,6 @@ For example:: It is possible to declare the return type of a callable without specifying the call signature by substituting a literal ellipsis for the list of arguments in the type hint: ``Callable[..., ReturnType]``. -``None`` as a type hint is a special case and is replaced by ``type(None)``. Generics -------- @@ -443,7 +445,7 @@ The module defines the following classes, functions and decorators: Optional type. - ``Optional[X]`` is equivalent to ``Union[X, type(None)]``. + ``Optional[X]`` is equivalent to ``Union[X, None]``. Note that this is not the same concept as an optional argument, which is one that has a default. An optional argument with a |