How to count the number of letters in a string without the spaces?

Question

This is my solution resulting in an error. Returns 0

PS: I'd still love a fix to my code :)

from collections import Counter
import string


def count_letters(word):
    global count
    wordsList = string.split(word)
    count = Counter()
    for words in wordsList:
        for letters in set(words):
            return count[letters]

word = "The grey old fox is an idiot"
print count_letters(word)

Answer 1

def count_letters(word):
    return len(word) - word.count(' ')

Alternatively, if you have multiple letters to ignore, you could filter the string:

def count_letters(word):
    BAD_LETTERS = " "
    return len([letter for letter in word if letter not in BAD_LETTERS])

Answer 2

Simply solution using the sum function:

sum(c != ' ' for c in word)

It's a memory efficient solution because it uses a generator rather than creating a temporary list and then calculating the sum of it.

It's worth to mention that c != ' ' returns True or False, which is a value of type bool, but bool is a subtype of int, so you can sum up bool values (True corresponds to 1 and False corresponds to 0)

You can check for an inheretance using the mro method:

>>> bool.mro() # Method Resolution Order
[<type 'bool'>, <type 'int'>, <type 'object'>]

Here you see that bool is a subtype of int which is a subtype of object.