How to concatenate element-wise two lists in Python?

Question

I have two lists and I want to concatenate them element-wise. One of the list is subjected to string-formatting before concatenation.

For example :

Answer 1

Than can be done elegantly with map and zip:

map(lambda (x,y): x+y, zip(list1, list2))

Example:

In [1]: map(lambda (x,y): x+y, zip([1,2,3,4],[4,5,6,7]))
Out[1]: [5, 7, 9, 11]