f'"{var:}"' adds redundant empty string literal in AST in 3.12 #106396
Description
3.11:
>>> import ast
>>> print(ast.dump(ast.parse("""f'"{var:}"'"""), indent=2))
Module(
body=[
Expr(
value=JoinedStr(
values=[
Constant(value='"'),
FormattedValue(
value=Name(id='var', ctx=Load()),
conversion=-1,
format_spec=JoinedStr(values=[])),
Constant(value='"')]))],
type_ignores=[])3.12:
>>> import ast
>>> print(ast.dump(ast.parse("""f'"{var:}"'"""), indent=2))
Module(
body=[
Expr(
value=JoinedStr(
values=[
Constant(value='"'),
FormattedValue(
value=Name(id='var', ctx=Load()),
conversion=-1,
format_spec=JoinedStr(
values=[
Constant(value='')])),
Constant(value='"')]))],
type_ignores=[])This affects several linters:
- Fix parse test case on Python 3.12 mypy#15577
- B907 crashes when bugbear is run on Python 3.12 PyCQA/flake8-bugbear#393
Is this a bug? Or is it a feature?