How can I make mock-0.6 return a sequence of values?

I'm using the mock-0.6 library from http://www.voidspace.org.uk/python/mock/mock.html to moc开发者_C百科k out a framework for testing, and I want to have a mock method return a series of values, each time it's called.

Right now, this is what I figured should work:

def returnList(items):
  def sideEffect(*args, **kwargs):
    for item in items:
      yield item
    yield mock.DEFAULT
  return sideEffect

mock = Mock(side_effect=returnList(aListOfValues))
values = mock()
log.info("Got %s", values)

And the log output is this:

subsys: INFO: Got <generator object func at 0x1021db500> 

So, the side effect is returning the generator, not the next value, which seems wrong. Where am I getting this wrong?

If you just want to return a list of values, the answer is easy if you're using mock==0.8.0 or later:

import mock 

m = mock.Mock() 
m = side_effect = [ 
    ['a', 'b', 'c'], 
    ['d', 'e', 'f'], 
] 

print "First: %s" % m() 
print "Second: %s" % m() 

The output is:

First: ['a', 'b', 'c']
Second: ['d', 'e', 'f']

If you want the same exact return value every time, then the answer is even simpler:

m = mock.Mock() 
m.return_value = ['a', 'b', 'c']
print m('foo') 
print m('bar') 
print m('baz') 

Here's the solution, found by trial and error:

The returnList function must create a generator and use its next method to provide the responses:

def returnList(items):
  log.debug("Creating side effect function for %s", items)
  def func():
    for item in items:
      log.debug("side effect yielding %s", item)
      yield item
    yield mock.DEFAULT

  generator = func()

  def effect(*args, **kwargs):
    return generator.next()

  return effect