Pycharm warning: must implement all abstract methods

Question:

Code

class A(object):
    def a(self):
        raise NotImplementedError

class B(A):
    def a(self):
        return 7

class C(B):
    pass

Why does Pycharm complain?

Problem synopsis      Class C must implement all abstract methods

Asked By: MrJ

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Source

Answers:

It’s a reported bug – you can vote for it here: https://youtrack.jetbrains.com/issue/PY-16132

Answered By: Mr_and_Mrs_D

As expected, python itself recognises that instances of Class C are valid. So I suspected an bug in PyCharm.

Googling for PyCharm Bug Tracker got me to https://youtrack.jetbrains.com/issues/PY

Sure enough a ticket has been raised.
https://youtrack.jetbrains.com/issue/PY-16132

No fix yet

Answered By: Guy Gangemi

We can disable this warning as follows:

  • Goto Preferences/Settings > Editor > Inspections
  • Search for Class must implement all abstract methods
  • uncheck it, then click apply
Answered By: Arun

I find that warning relevant, so I would not disable it globally. You can instrument a false positive (erroneous warning) with # noqa and it should silence the PyCharm warning:

class MySerializer(serializers.Serializer):  # noqa
   pass

note: I have not found a narrower warning/error code.

Answered By: Raffi