[Zope] help with error message

[Tuttle, Gene]

Can some one help me with this error?
Error Value: You are not allowed to access 'SequenceMatcher' in this context

Does this say that I cannot use difflib in python script?

here is the snippet of code:
	# find the record that matches the best
	s = difflib.SequenceMatcher(None, name_first, R['name_first'])
	v1 =  round(s.ratio(), 3)

I am trying to determine if a record in the database is close to the data
submitted by the user.
An example is the address 914 Lois lane and 914 Lois LN 
With SequenceMatcher this returns a 97% probability that these two are the
same.


Thanks
Gene