Python: Sum string lengths

Question

Is there a more idiomatic way to sum string lengths in Python than by using a loop?

length = 0
for string in strings:
    length += len(string)

Answer 1

The shortest and fastest way is apply a functional programming style with map() and sum():

>>> data = ['a', 'bc', 'def', 'ghij']
>>> sum(map(len, data))
10

In Python 2, use itertools.imap instead of map for better memory performance:

>>> from itertools import imap
>>> data = ['a', 'bc', 'def', 'ghij']
>>> sum(imap(len, data))
10