Problem in understanding Python list comprehensions

Question

What does the last line mean in the following code?

import pickle, urllib                                                                                                 


        

Answer 1

The question itself has already been fully answered but I'd like to add that a list comprehension also supports filtering. Your original line

print "".join([e[1] * e[0] for e in elt])

could, as an example, become

print "".join([e[1] * e[0] for e in elt if len(e) == 2])

to only operate on items in elt that have two elements.