There is a sets.Set class built in to Python. You might want to use this instead of lists. It defines some handy set operations like intersection, union, and so on.
from sets import Set my_sets = { 'one' : Set([0,4,7,9]), 'two' : Set([0,3,7,9]), etc... } -- http://mail.python.org/mailman/listinfo/python-list