gh-118761: Lazily import annotationlib in typing #132060
Merged
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
annotationlib is used quite a few times in typing.py, but I think the usages are just rare enough that this makes sense. The import would get triggered by: - Using get_type_hints(), evaluate_forward_ref(), and similar introspection functions - Using a string annotation anywhere that goes through _type_convert (e.g., "Final['x']" will trigger an annotationlib import in order to access the ForwardRef class). - Creating a TypedDict or NamedTuple (unless it's empty or PEP 563 is on). Lots of programs will want to use typing without any of these, so the tradeoff seems worth it.
AlexWaygood
reviewed
Apr 4, 2025
Member
AlexWaygood
left a comment
There was a problem hiding this comment.
I agree with the concept, but I think there's some opportunities to make this simpler and faster
AlexWaygood
approved these changes
Apr 4, 2025
Member
AlexWaygood
left a comment
There was a problem hiding this comment.
the code doesn't look so pretty anymore, but I'm fine with this if it significantly speeds up the import time! (Do you have any numbers there?)
Member
Author
|
On this branch with On main: |
Member
|
Nice work, thank you!! |
10 tasks
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 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Outdated suggestions cannot be applied.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.
annotationlib is used quite a few times in typing.py, but I think the
usages are just rare enough that this makes sense.
The import would get triggered by:
functions
"Final['x']" will trigger an annotationlib import in order to access the
ForwardRef class).
Lots of programs will want to use typing without any of these, so the tradeoff
seems worth it.