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)

I tried sum(), but it only works for integers:

>>> sum('abc', 'de')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: sum() can't sum strings [use ''.join(seq) instead]

Answer 1

Here's another way using operator. Not sure if this is easier to read than the accepted answer.

import operator

length = reduce(operator.add, map(len, strings))

print length

Answer 2

length = sum(len(s) for s in strings)

Answer 3

print(sum(len(mystr) for mystr in strings))

Answer 4

Just to add upon ...

Adding numbers from a list stored as a string

nos = ['1','14','34']

length = sum(int(s) for s in nos)

Answer 5

I know this is an old question, but I can't help noting that the Python error message tells you how to do this:

TypeError: sum() can't sum strings [use ''.join(seq) instead]

So:

>>> strings = ['abc', 'de']
>>> print len(''.join(strings))
5

Answer 6

My first way to do it would be sum(map(len, strings)). Another way is to use a list comprehension or generator expression as the other answers have posted.