One reason to import modules instead of names directly

test_undertest.py

import unittest
import mock  # or `from unittest import mock` in py3.3+

import undertest1
import undertest2



class MockDemoTestCase(unittest.TestCase):
    # we can directly patch givestring's module namespace.
    @mock.patch('othermodule.givestring', return_value='expected result')
    def test_undertest1_use_othermodule_function(self, mocked_func):
        self.assertEqual(undertest1.use_othermodule_function(), ['expected', 'result'])
        mocked_func.assert_called_with('somearg')

    # We must patch undertest2's namespace because `givestring` has been
    # imported directly.
    @mock.patch('undertest2.givestring', return_value='expected result')
    def test_undertest2_use_othermodule_function(self, mocked_func):
        self.assertEqual(undertest2.use_othermodule_function(), ['expected', 'result'])
        mocked_func.assert_called_with('somearg')

undertest1.py

import othermodule


def use_othermodule_function():
    result = othermodule.givestring('somearg')
    return result.split()

undertest2.py

from othermodule import givestring


def use_othermodule_function():
    result = givestring('somearg')
    return result.split()