Reuse stdlib PEP 593 implementation in typing_extensions if present #699
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Following [1] this prevents multiple runtime implementations of Annotated and get_type_hints from existing on Python 3.9 (which has recently merged PEP 593 changes[2]). Reexporting allows code targetting both Python pre-3.9 and 3.9+ to be able to import from typing_extensions and to keep working without changes. [1] python/cpython#18260 (comment) [2] python/cpython#18260
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Following [1] this prevents multiple runtime implementations of Annotated
and get_type_hints from existing on Python 3.9 (which has recently
merged PEP 593 changes[2]). Reexporting allows code targetting both
Python pre-3.9 and 3.9+ to be able to import from typing_extensions and
to keep working without changes.
_AnnotatedAliasimport is needed for #698 to work.[1] python/cpython#18260 (comment)
[2] python/cpython#18260