问题描述
我正在尝试以某种方式模拟 urllib2.urlopen 库,以便对传递给函数的不同 url 获得不同的响应.
I am trying to mock the urllib2.urlopen library in a way that I should get different responses for different urls I pass into the function.
我现在在测试文件中的做法是这样的
The way I am doing it in my test file now is like this
@patch(othermodule.urllib2.urlopen) def mytest(self, mock_of_urllib2_urllopen): a = Mock() a.read.side_effect = ["response1", "response2"] mock_of_urllib2_urlopen.return_value = a othermodule.function_to_be_tested() #this is the function which uses urllib2.urlopen.read
我希望 othermodule.function_to_be_tested 在第一次调用时获得值response1",在第二次调用时获得值response2",这就是 side_effect 的作用
I expect the the othermodule.function_to_be_tested to get the value "response1" on first call and "response2" on second call which is what side_effect will do
但是 othermodule.function_to_be_tested() 接收
but the othermodule.function_to_be_tested() receives
<MagicMock name='urlopen().read()' id='216621051472'>
而不是实际的响应.请建议我哪里出错了或更简单的方法.
and not the actual response. Please suggest where I am going wrong or an easier way to do this.
推荐答案
patch的参数需要是对象的location的描述,而不是对象本身.因此,您的问题看起来可能只是您需要将参数字符串化为 patch.
The argument to patch needs to be a description of the location of the object, not the object itself. So your problem looks like it may just be that you need to stringify your argument to patch.
不过,为了完整起见,这里有一个完整的示例.首先,我们的待测模块:
Just for completeness, though, here's a fully working example. First, our module under test:
# mod_a.py import urllib2 def myfunc(): opened_url = urllib2.urlopen() return opened_url.read()
现在,设置我们的测试:
Now, set up our test:
# test.py from mock import patch, Mock import mod_a @patch('mod_a.urllib2.urlopen') def mytest(mock_urlopen): a = Mock() a.read.side_effect = ['resp1', 'resp2'] mock_urlopen.return_value = a res = mod_a.myfunc() print res assert res == 'resp1' res = mod_a.myfunc() print res assert res == 'resp2' mytest()
从 shell 运行测试:
Running the test from the shell:
$ python test.py resp1 resp2
编辑:糟糕,最初包含原始错误.(正在测试以验证它是如何被破坏的.)现在应该修复代码.
Edit: Whoops, initially included the original mistake. (Was testing to verify how it was broken.) Code should be fixed now.