Python Testing Example - How to mock property for testing

testing-example.py

import unittest
import mock


class Trainer(object):

    @property
    def column_names(self):
        return ["one", "two"]

    def ret_column_names(self):
        return self.column_names


class Tester(unittest.TestCase):

    @mock.patch.object(Trainer, "column_names")
    def test_ret_column_names(self, mock_column_names):
        trainer = Trainer
        columns = ['three', 'four']
        mock_column_names.__get__ = mock.Mock(return_value=columns)
        self.assertEquals(trainer.ret_column_names(), columns)