Mocking urllib2.urlopen().read() for different responses

Question

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.

The way I am doing it in

Answer 1

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.

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()

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()

Running the test from the shell:

$ python test.py
resp1
resp2

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