Collective Intelligence chapter 2

I'm trying to run the critics program in ch 2, and am getting the following error:

>>> import recommendations
>>> reload(recommendations)
<module 'recommendations' from 'C:\Python27\Lib\recommendations.pyc'>
>>> recommendations.sim_distance(recommendations.critics,'Lisa Rose','Gene Seymour')
Traceback (most recent call last):
File "<interactive input>", line 1, in <module>
File "C:\Python27\Lib\recommendations.py", line 92, in sim_distance
for item in sim_distance])
TypeError: 'function' object is not iterable
>>>

Please advise. Thank you