TypeError: 'A' object is not subscriptable

What it does

Checks for implicit calls to possibly missing methods.

Why is this bad?

Expressions such as x[y] and x * y call methods under the hood (__getitem__ and __mul__ respectively). Calling a missing method will raise an AttributeError at runtime.

Examples

import datetime


class A:
    if datetime.date.today().weekday() != 6:

        def __getitem__(self, v): ...


# TypeError: 'A' object is not subscriptable
A()[0]  # error