testmock.py 文件源码

def test_mock_open_alter_readline(self):
        mopen = mock.mock_open(read_data='foo\nbarn')
        mopen.return_value.readline.side_effect = lambda *args:'abc'
        first = mopen().readline()
        second = mopen().readline()
        self.assertEqual('abc', first)
        self.assertEqual('abc', second)