import string


def is_isogram(word):
    letters = [letter.lower() for letter in word if letter.isalpha()]
    return len(letters) == len(set(letters))

6ec71cc20e61956d8640146a0b47383cda6f6b4c
<mask token>

<mask token>


def is_isogram(word):
    letters = [letter.lower() for letter in word if letter.isalpha()]
    return len(letters) == len(set(letters))

import string


def is_isogram(word):
    letters = [letter.lower() for letter in word if letter.isalpha()]
    return len(letters) == len(set(letters))
