FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

bpo-41370: Evaluate strings as forward refs in PEP 585 generics by NiklasRosenstein · Pull Request #30900 · python/cpython · GitHub

  1. python
  2. cpython

Repository navigation

bpo-41370: Evaluate strings as forward refs in PEP 585 generics #30900

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
gvanrossum merged 10 commits into from
Mar 7, 2022
Conversation 17 Commits 10 Checks 0 Files changed
Merged

bpo-41370: Evaluate strings as forward refs in PEP 585 generics #30900

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
10 commits
Select commit Hold shift + click to select a range
e820e3a
convert strings in PEP 585 generic aliases (`types.GenericAlias`) to …
NiklasRosenstein Jan 25, 2022
d7f57c7
add unittest for new get_type_hints() behaviour on PEP 585 generics w…
NiklasRosenstein Jan 25, 2022
26ab740
add unit test for `from __future__ import annotations`
NiklasRosenstein Jan 27, 2022
a04bd5d
add test for recursive type
NiklasRosenstein Jan 27, 2022
3416713
📜🤖 Added by blurb_it.
blurb-it[bot] Jan 27, 2022
30a3564
Double backticks because RST.
NiklasRosenstein Jan 27, 2022
13a3505
Update Lib/typing.py
NiklasRosenstein Jan 27, 2022
33d286a
Update Misc/NEWS.d/next/Library/2022-01-27-11-54-16.bpo-41370.gYxCPE.rst
NiklasRosenstein Jan 27, 2022
6cd96b1
Merge branch 'main' into issue41370
NiklasRosenstein Feb 22, 2022
39c5b06
Replace assertIs with assertEqual in test_get_type_hints_annotated
NiklasRosenstein Mar 3, 2022
File filter

Filter by extension

Filter by extension .py  (2) All 1 file type selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
17 changes: 17 additions & 0 deletions Lib/test/test_typing.py
Show comments
View file
Open in desktop
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
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -2006,6 +2006,23 @@ def barfoo(x: AT): ...
def barfoo2(x: CT): ...
self.assertIs(get_type_hints(barfoo2, globals(), locals())['x'], CT)

def test_generic_pep585_forward_ref(self):
# See https://bugs.python.org/issue41370

class N:
a: list['N']
self.assertEqual(
get_type_hints(N, globals(), locals()),
{'a': list[N]}
)

class M:
a: dict['N', list[List[list['M']]]]
self.assertEqual(
get_type_hints(M, globals(), locals()),
{'a': dict[N, list[List[list[M]]]]}
)

def test_extended_generic_rules_subclassing(self):
class T1(Tuple[T, KT]): ...
class T2(Tuple[T, ...]): ...
Expand Down
6 changes: 6 additions & 0 deletions Lib/typing.py
Show comments
View file
Open in desktop
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
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -331,6 +331,12 @@ def _eval_type(t, globalns, localns, recursive_guard=frozenset()):
if isinstance(t, ForwardRef):
return t._evaluate(globalns, localns, recursive_guard)
if isinstance(t, (_GenericAlias, GenericAlias, types.UnionType)):
if isinstance(t, GenericAlias):
args = tuple(
ForwardRef(arg) if isinstance(arg, str) else arg

sobolevn Feb 19, 2022

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

Do we need to pass globals and locals to ForwardRef here? 🤔

NiklasRosenstein Feb 22, 2022

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

I may not be knowledgable enough about the typing code base, but I don't see a globals/locals argument for ForwardRef. Do you mean the module? I couldn't find out how to use/what to pass to that argument exactly.

gvanrossum Mar 3, 2022

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

It's too late for that anyway. The ForwardRef class has an optional module= argument which may be used to resolve references, but the best we could do at this point is passing globalns.get("__name__"), which would just end up with the same globalns as we are using anyway.

This suggests there could still be scenarios where this will fail, esp. when a type alias defined in one module is used in another. But that would only be solvable by recording the module at the time the alias is being defined, and we've already said we wouldn't go that far (since it would require a ForwardRef implementation in C).
for arg in t.__args__
)
t = t.__origin__[(*args,)]
Comment thread
NiklasRosenstein marked this conversation as resolved.
Resolved
ev_args = tuple(_eval_type(a, globalns, localns, recursive_guard) for a in t.__args__)
if ev_args == t.__args__:
return t
Expand Down
Back | FazBrowse Home | New Git URL