問(wèn)題描述

我正在嘗試以某種方式模擬 urllib2.urlopen 庫(kù)，以便對(duì)傳遞給函數(shù)的不同 url 獲得不同的響應(yīng).

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.

我現(xiàn)在在測(cè)試文件中的做法是這樣的

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 在第一次調(diào)用時(shí)獲得值response1"，在第二次調(diào)用時(shí)獲得值response2"，這就是 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'>

而不是實(shí)際的響應(yīng).請(qǐng)建議我哪里出錯(cuò)了或更簡(jiǎn)單的方法.

and not the actual response. Please suggest where I am going wrong or an easier way to do this.

推薦答案

patch的參數(shù)需要是對(duì)象的location的描述，而不是對(duì)象本身.因此，您的問(wèn)題看起來(lái)可能只是您需要將參數(shù)字符串化為 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.

不過(guò)，為了完整起見(jiàn)，這里有一個(gè)完整的示例.首先，我們的待測(cè)模塊:

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()

現(xiàn)在，設(shè)置我們的測(cè)試:

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()

從 shell 運(yùn)行測(cè)試:

Running the test from the shell:

$ python test.py
resp1
resp2

編輯:糟糕，最初包含原始錯(cuò)誤.(正在測(cè)試以驗(yàn)證它是如何被破壞的.)現(xiàn)在應(yīng)該修復(fù)代碼.

Edit: Whoops, initially included the original mistake. (Was testing to verify how it was broken.) Code should be fixed now.

這篇關(guān)于模擬 urllib2.urlopen().read() 以獲得不同的響應(yīng)的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！