如何使用带Python UnitTest decorator的mock_open？

Question

我有一个测试如下：

import mock

# other test code, test suite class declaration here

@mock.patch("other_file.another_method")
@mock.patch("other_file.open", new=mock.mock_open(read=["First line", "Second line"])
def test_file_open_and_read(self, mock_open_method, mock_another_method):
    self.assertTrue(True) # Various assertions.

我得到以下错误：

TypeError: test_file_open_and_read() takes exactly 3 arguments (2 given)

我试图指定我希望用mock.mock_open而不是mock.MagicMock来模拟另一个文件的__builtin__.open方法，这是patch装饰器的默认行为。我该怎么做？在

Answer 1

您错过了来自open内建的参数create。在

@mock.patch("other_file.open", new=mock.mock_open(read=["First line", "Second line"], create=True)