Skip to content
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

Jump to bottom

Fix false positive used-before-assignment in pattern matching with a guard #7793

Closed
wants to merge 10 commits into from
Closed

Fix false positive used-before-assignment in pattern matching with a guard #7793

Show file tree
Hide file tree
Changes from 9 commits
Commits
Show all changes
10 commits
Select commit Hold shift + click to select a range
b38da73
Fix false positive `used-before-assignment` in pattern matching with …
Nov 18, 2022
c7e0122
Typo fix
Nov 18, 2022
b6bfabe
Added whatsnew
Nov 18, 2022
2e5baef
[pre-commit.ci] auto fixes from pre-commit.com hooks
pre-commit-ci[bot] Nov 18, 2022
5a0e6ee
Whatsnew format fix
Nov 18, 2022
727feaa
Py10 and up only
Nov 18, 2022
cd31a5a
Catch up with main
Nov 18, 2022
6103fa7
Merge branch 'main' of github.com:i-likecheese/pylint
Nov 18, 2022
0b3276b
[pre-commit.ci] auto fixes from pre-commit.com hooks
pre-commit-ci[bot] Nov 18, 2022
be2bffe
Merge branch 'PyCQA:main' into main
i-likecheese Nov 22, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions doc/whatsnew/fragments/5327.false_positive
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
Don't emit ``used-before-assignment`` in pattern matching with a guard.

Closes #5327
5 changes: 5 additions & 0 deletions pylint/checkers/variables.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
)
from pylint.constants import (
PY39_PLUS,
PY310_PLUS,
TYPING_NEVER,
TYPING_NORETURN,
TYPING_TYPE_CHECKS_GUARDS,
Expand Down Expand Up @@ -1641,6 +1642,10 @@ def _check_consumer(
if not (
self._postponed_evaluation_enabled
and isinstance(stmt, (nodes.AnnAssign, nodes.FunctionDef))
) and not (
PY310_PLUS
and isinstance(stmt, nodes.Match)
and isinstance(node.parent, nodes.Compare)
Comment on lines +1698 to +1701
Copy link
Member

Choose a reason for hiding this comment

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

This doesn't solve this false positive, because the .parent is nodes.Name:

match ("example", "one"):
    case (x, y) if x:  # <-- pylint complains about 'x' here
        print("woo!")
    case _:
        print("boo...")

):
self.add_message(
"used-before-assignment",
Expand Down
1 change: 1 addition & 0 deletions pylint/constants.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@

PY38_PLUS = sys.version_info[:2] >= (3, 8)
PY39_PLUS = sys.version_info[:2] >= (3, 9)
PY310_PLUS = sys.version_info[:2] >= (3, 10)

IS_PYPY = platform.python_implementation() == "PyPy"

Expand Down