Overwrite base class's methods.

overwrite_base.py

# -*- coding: utf-8 -*-

"""
Overwrite base class's methods.
"""

import unittest

class Base(object):

    def level(self):
        return 0


class Level1(Base):

    def level(self):
        return 1

class Level2(Base):
    pass


class TestInherit(unittest.TestCase):

    def test_normal(self):
        self.assertEqual(  Base().level(), 0)
        self.assertEqual(Level1().level(), 1)
        self.assertEqual(Level2().level(), 0)

    def test_overwrite(self):

        self.assertEqual(Level2().level(), 0)

        def level(self):
            return -1
        Base.level = level

        self.assertEqual(  Base().level(), -1)
        self.assertEqual(Level1().level(), 1)
        self.assertEqual(Level2().level(), -1)


if __name__ == '__main__': unittest.main()