Example of Pythons duck typing

duck_typing.py

"""
Example do demonstrate Python's Duck Typing

In [1]: from collections import Container

In [2]: Container.__abstractmethods__
Out[3]: frozenset({'__contains__'})

"""

import collections


class MyContainer:
    def __contains__(self, item):
        pass

my_container = MyContainer()

assert isinstance(my_container, collections.Container)
assert issubclass(MyContainer, collections.Container)