在python单元中使不会导致测试失败的异常静音

Question

我正在使用unittest框架为python程序编写单元测试。程序的功能之一是使用请求库连接到外部restapi。如果出现连接错误或超时，我希望函数在失败之前最多重试3次。因此，我编写了一个使用mock（实际上是httpretty）替换外部API并引发请求连接错误两次之后才还东西。在

class APITests(unittest.TestCase):

    def mock_response(self, uri, body='OK', method=httpretty.GET,
                      status_code=200, error=None,
                      error_repeats=None):
        """
        Function to register HTTPretty response
        """
        responses = []

        if error:
            def callback(request, uri, headers):
                raise error

            if error_repeats:
                responses += [httpretty.Response(body=callback)]*error_repeats
                responses += [httpretty.Response(body=body,
                                                 status=status_code)]
            else:
                responses += [httpretty.Response(body=callback)]

        else:
            responses += [httpretty.Response(body=body, status=status_code)]

        httpretty.register_uri(method, uri, responses=responses)

    @httpretty.activate
    def test_get_connection_error_then_success_doesnt_raise(self):
        self.mock_response(
                'http://irrelevant.com',
                error=requests.ConnectionError,
                error_repeats=2
            )
        api._get('http://irrelevant.com')  

当第三次尝试未引发异常时，此方法工作正常，测试通过，但两个异常（故意）被引发并由代码捕获和处理，将打印到控制台，从而污染测试输出。有没有一个干净的方法来阻止这种情况的发生？在

更多信息

这是我正在测试的方法

^{pr2}$

控制台输出为：

Exception in thread Thread-23:
Traceback (most recent call last):
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 763, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/Users/lukecaldwell/Documents/Repos/other/AidTrends/venv/lib/python2.7/site-packages/httpretty/core.py", line 637, in fill_filekind
    headers
  File "/Users/lukecaldwell/Documents/Repos/other/AidTrends/aidtrends/tests/test_OECD.py", line 131, in callback
    raise error
ConnectionError