This shows users that they can use the actual types. Using deprecated types is confusing.
This also prefers colections.abc.Sized instead of the alias typing.Sized. I guess the aliases were created to make it convenient to import all collections related types from the same place.
This should be backported to 3.9.
Automerge-Triggered-By: @gvanrossum
* bpo-39491: Merge PEP 593 (typing.Annotated) support
PEP 593 has been accepted some time ago. I got a green light for merging
this from Till, so I went ahead and combined the code contributed to
typing_extensions[1] and the documentation from the PEP 593 text[2].
My changes were limited to:
* removing code designed for typing_extensions to run on older Python
versions
* removing some irrelevant parts of the PEP text when copying it over as
documentation and otherwise changing few small bits to better serve
the purpose
* changing the get_type_hints signature to match reality (parameter
names)
I wasn't entirely sure how to go about crediting the authors but I used
my best judgment, let me know if something needs changing in this
regard.
[1] 8280de241f/typing_extensions/src_py3/typing_extensions.py
[2] 17710b8798/pep-0593.rst
PR #4906 changed the typing.Generic class hierarchy, leaving an
outdated comment in the library reference. User-defined Generic ABCs now
must get a abc.ABCMeta metaclass from something other than typing.Generic
inheritance.
This PR replaces the old note mentioning that `typing` is a provisional module with a new one mentioning types are not enforced at runtime. I am not sure if there was any official announcement about making `typing` non-provisional, but _de-facto_ no new features were added during Python 3.7, and no backwards incompatible changes were made except for few small things that were considered bugs.
https://bugs.python.org/issue37814:
> The empty tuple syntax in type annotations, `Tuple[()]`, is not obvious from the examples given in the documentation (I naively expected `Tuple[]` to work); it has been documented in PEP 484 and in mypy, but not in the documentation for the typing module.
https://bugs.python.org/issue37814
This is an old feature request that appears from time to time. After a year of experimenting with various introspection capabilities in `typing_inspect` on PyPI, I propose to add these two most commonly used functions: `get_origin()` and `get_args()`. These are essentially thin public wrappers around private APIs: `__origin__` and `__args__`.
As discussed in the issue and on the typing tracker, exposing some public helpers instead of `__origin__` and `__args__` directly will give us more flexibility if we will decide to update the internal representation, while still maintaining backwards compatibility.
The implementation is very simple an is essentially a copy from `typing_inspect` with one exception: `ClassVar` was special-cased in `typing_inspect`, but I think this special-casing doesn't really help and only makes things more complicated.
I tried to get rid of the `_ProtocolMeta`, but unfortunately it didn'y work. My idea to return a generic alias from `@runtime_checkable` made runtime protocols unpickleable. I am not sure what is worse (a custom metaclass or having some classes unpickleable), so I decided to stick with the status quo (since there were no complains so far). So essentially this is a copy of the implementation in `typing_extensions` with two modifications:
* Rename `@runtime` to `@runtime_checkable` (plus corresponding updates).
* Allow protocols that extend `collections.abc.Iterable` etc.
The implementation is straightforward, it just mimics `ClassVar` (since the latter is also a name/access qualifier, not really a type). Also it is essentially copied from `typing_extensions`.
In order to support typing checks calling hex(), oct() and bin() on user-defined classes, a SupportIndex protocol is required. The ability to check these at runtime would be good to add for completeness sake. This is pretty much just a copy of SupportsInt with the names tweaked.
* Replace external recipe link with a link to the dataclasses module.
* Highlight the class definition syntax for typing.NamedTuple
and add an example for clarity.
Currently, the docs state that when doing `Type[X]`, X is only allowed to
be a class, a union of classes, and Any. This pull request amends
that sentence to clarify X may also be a typevar (or a union involving
classes, Any, and TypeVars).