Missed this occurrence before, sorry. Also changed "the PEP" to "PEP".
Automerge-Triggered-By: @gvanrossum
(cherry picked from commit 3fe6148937)
Co-authored-by: Andre Delfino <adelfino@gmail.com>
Metaclass was removed in Python 3.7 (there is already a `versionchanged` item about this).
https://bugs.python.org/issue28556
(cherry picked from commit 8144095707)
Co-authored-by: Ivan Levkivskyi <levkivskyi@gmail.com>
PR GH-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outdated comment in the library reference.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.
(cherry picked from commit d47f0dd2e8)
Co-authored-by: M. Eric Irrgang <mei2n@virginia.edu>
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.
(cherry picked from commit 81528ba2e8)
Co-authored-by: Ivan Levkivskyi <levkivskyi@gmail.com>
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
(cherry picked from commit 8a784af750)
Co-authored-by: Josh Holland <anowlcalledjosh@gmail.com>
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).
* Fix PEP 8 (SomeType instead of some_type)
* Add a function parameter annotation
* Explain, using wording from PEP 484 and PEP 526,
why one annotation is in quotes and another is not.
Suggested by Ivan Levkevskyi.