Repository navigation
Overriding final method only raises error if overriding method is annotated #7015
Description
In the code below I expected both subclasses to raise errors due to overriding method marked with @final, but only the B class raises an error, it seems like adding the return type annotation triggers the check. The same behavior is not specific to __init__ but happens with any method name.
from typing_extensions import final
class Base:
@final
def __init__(self):
pass
class A(Base):
def __init__(self): # no error raised
pass
class B(Base):
def __init__(self) -> None: # raises an error
passsetup.cfg:
[mypy]
ignore_missing_imports = True
strict_optional = True
no_implicit_optional = True
check_untyped_defs = True
disallow_incomplete_defs = True
disallow_any_unimported = True
disallow_untyped_decorators = True
Same result with both master mypy 0.710+dev.44172caa122b01af5a63ec5787931b910f272eb6 and latest stable mypy 0.701 using Python 3.7.0.
Activity
[-]Bug: Final __init__ only raises error if sub-class __init__ is annotated [/-][+]Bug: Overriding final method only raises error if overriding method is annotated [/+]ilevkivskyi commentedon Jun 18, 2019
Yes, indeed, this happens with all methods, not just
__init__(). I think mypy should give an error even for non-annotated methods.[-]Bug: Overriding final method only raises error if overriding method is annotated [/-][+]Overriding final method only raises error if overriding method is annotated [/+]