模拟补丁导致错误-TypeError:object()在Python3中不接受任何参数

这有点复杂,因为我正在调试一些很久以前用python2.7编写的代码

在迁移到python3的过程中(我知道,我知道),在尝试修复单元测试时遇到了这个问题

TypeError: object() takes no parameters

我将列出下面的函数。我必须替换很多函数和对象的名称。如果您看到模块名称不一致,请假定是输入错误。

首先是它呼叫的班级

class Parser(object):
    def __init__(self, some_instance, some_file):
        self._some_instance = some_instance
        self.stream = Parser.formsomestream(some_file)
        self.errors = []

    @staticmethod
    def formsomestream(some_file):
        # return a stream


class BetterParser(Parser):

    def parse(self):
        # skip some steps, shouldn't relate to the problem
        return details  # this is a string

class CSVUploadManager(object):
    def __init__(self, model_instance, upload_file):
        self._model_instance = model_instance
        self._upload_file = upload_file
    # then bunch of functions here
    # then.....
    def _parse(self):
        parser_instance = self._parser_class(self._model_instance, self._upload_file)
        self._csv_details = parser_instance.parse()
        # bunch of stuff follows
    def _validate(self):
        if not self._parsed:
            self._parse()
        validator_instance = self._validator_class(self._model_instance, self._csv_details)
        # some attributes to set up here

    def is_valid(self):
        if not self._validated:
            self._validate()

现在测试函数 从somewhere.to.this.validator导入MockUploadValidator 从另一个.place导入CSVUploadManager

class TestSomething(SomeConfigsToBeMixedIn):
    @mock.patch('path.to.BetterParser.parse')
    @mock.patch('path.to.SomeValidator.__new__')
    @mock.patch('path.to.SomeValidator.validate')

    def test_validator_is_called(self, mock_validator_new, mock_parse):
        mock_validator_new.return_value = MockUploadValidator.__new__(MockUploadValidator)
        mock_parse.return_value = mock_csv_details
        mock_validator_new.return_value = MockUploadValidator()

        string_io = build_some_string_io_woohoo()  # this returns a StringIO
        some_file = get_temp_from_stream(string_io)

        upload_manager = CSVUploadManager(a_model_instance, some_file)
        upload_manager.is_valid() # this is where it fails and produces that error

        self.assertTrue(mock_parse.called)
        self.assertTrue(mock_validator_new.called)
        validator_new_call_args = (SomeValidator, self.cash_activity, mock_csv_details)
        self.assertEqual(mock_validator_new._mock_call_args_list[0][0], validator_new_call_args)

如您所见,CSVUploadManager接收django模型实例和类似obj的文件,这会触发 self._parser_class BetterParser ,那么 做它的事情。

TypeError:object()不接受任何参数

1. 为什么会出现这种错误?
3. 这也会导致其他测试(在不同的测试用例中)失败,如果我不使用失败的测试来测试它们,它们通常会通过。为什么?

编辑:添加回溯

Traceback (most recent call last):
  File "/path/to/lib/python3.6/site-packages/mock/mock.py", line 1305, in patched
    return func(*args, **keywargs)
  File "/path/to/test_file.py", line 39, in test_validator_is_called:
    upload_manager.is_valid()
  File "/path/to/manager.py", line 55, in is_valid
    self._validate()
  File "/path/to/manager.py", line 36, in _validate
    validator_instance = self._validator_class(self._model_instance, self._csv_details)
TypeError: object() takes no parameters