相关疑难解决方法(0)

我有一个源代码打开一个csv文件并设置一个标头值关联.源代码如下:

def ParseCsvFile(source): 
  """Parse the csv file. 
  Args: 
    source: file to be parsed

  Returns: the list of dictionary entities; each dictionary contains
             attribute to value mapping or its equivalent. 
  """ 
  global rack_file 
  rack_type_file = None 
  try: 
    rack_file = source 
    rack_type_file = open(rack_file)  # Need to mock this line.
    headers = rack_type_file.readline().split(',') 
    length = len(headers) 
    reader = csv.reader(rack_type_file, delimiter=',') 
    attributes_list=[] # list of dictionaries. 
    for line in reader: 
      # More process to happeng. Converting the rack name to sequence. 
      attributes_list.append(dict((headers[i],
                                   line[i]) …

我应该如何自定义unittest.mock.mock_open来处理这段代码？

file: impexpdemo.py
def import_register(register_fn):
    with open(register_fn) as f:
        return [line for line in f]

我第一次尝试尝试read_data.

class TestByteOrderMark1(unittest.TestCase):
    REGISTER_FN = 'test_dummy_path'
    TEST_TEXT = ['test text 1\n', 'test text 2\n']

    def test_byte_order_mark_absent(self):
        m = unittest.mock.mock_open(read_data=self.TEST_TEXT)
        with unittest.mock.patch('builtins.open', m):
            result = impexpdemo.import_register(self.REGISTER_FN)
            self.assertEqual(result, self.TEST_TEXT)

这失败了,大概是因为代码不使用read,readline或readlines.unittest.mock.mock_open 的文档说:"read_data是要返回的文件句柄的read(),readline()和readlines()方法的字符串.对这些方法的调用将从read_data中获取数据,直到它耗尽为止这些方法的模拟非常简单.如果你需要更多地控制你要测试代码的数据,你需要自己定制这个模拟.默认情况下,read_data是一个空字符串."

由于文件没有给出暗示上会需要什么样定制我试图return_value和side_effect.都没有奏效.

class TestByteOrderMark2(unittest.TestCase):
    REGISTER_FN = 'test_dummy_path'
    TEST_TEXT = ['test text 1\n', 'test text 2\n']

    def test_byte_order_mark_absent(self):
        m = unittest.mock.mock_open()
        m().side_effect = self.TEST_TEXT
        with unittest.mock.patch('builtins.open', m):
            result = impexpdemo.import_register(self.REGISTER_FN) …