mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-09-03 15:31:08 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 11

bpo-37759: Add examples for the new typing features (GH-16763)

Browse source
This commit is contained in:
Raymond Hettinger 2019-10-13 23:32:03 -07:00 • committed by GitHub
parent 61a6db5e79
commit a3291531ea
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 21 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

26
Doc/whatsnew/3.8.rst
View file

@ -1048,17 +1048,33 @@ typing
The :mod:`typing` module incorporates several new features: The :mod:`typing` module incorporates several new features:
* Protocol definitions. See :pep:`544`, :class:`typing.Protocol` and
:func:`typing.runtime_checkable`. Simple ABCs like
:class:`typing.SupportsInt` are now ``Protocol`` subclasses.
* A dictionary type with per-key types. See :pep:`589` and * A dictionary type with per-key types. See :pep:`589` and
:class:`typing.TypedDict`. :class:`typing.TypedDict`.
TypedDict uses only string keys. By default, every key is required
to be present. Specify "total=False" to allow keys to be optional::
class Location(TypedDict, total=False):
lat_long: tuple
grid_square: str
xy_coordinate: tuple
* Literal types. See :pep:`586` and :class:`typing.Literal`. * Literal types. See :pep:`586` and :class:`typing.Literal`.
Literal types indicate that a parameter or return value
is constrained to one or more specific literal values::
def get_status(port: int) -> Literal['connected', 'disconnected']:
...
* "Final" variables, functions, methods and classes. See :pep:`591`, * "Final" variables, functions, methods and classes. See :pep:`591`,
:class:`typing.Final` and :func:`typing.final`. :class:`typing.Final` and :func:`typing.final`.
The final qualifier instructs a static type checker to restrict
subclassing, overriding, or reassignment::
pi: Final[float] = 3.1415926536
* Protocol definitions. See :pep:`544`, :class:`typing.Protocol` and
:func:`typing.runtime_checkable`. Simple ABCs like
:class:`typing.SupportsInt` are now ``Protocol`` subclasses.
* New protocol class :class:`typing.SupportsIndex`. * New protocol class :class:`typing.SupportsIndex`.
@ -1527,7 +1543,7 @@ Changes in Python behavior
terminate the current thread if called while the interpreter is terminate the current thread if called while the interpreter is
finalizing, making them consistent with :c:func:`PyEval_RestoreThread`, finalizing, making them consistent with :c:func:`PyEval_RestoreThread`,
:c:func:`Py_END_ALLOW_THREADS`, and :c:func:`PyGILState_Ensure`. If this :c:func:`Py_END_ALLOW_THREADS`, and :c:func:`PyGILState_Ensure`. If this
behaviour is not desired, guard the call by checking :c:func:`_Py_IsFinalizing` behavior is not desired, guard the call by checking :c:func:`_Py_IsFinalizing`
or :c:func:`sys.is_finalizing`. or :c:func:`sys.is_finalizing`.
Changes in the Python API Changes in the Python API