Checking if two strings are permutations of each other in Python

Question

I\'m checking if two strings a and b are permutations of each other, and I\'m wondering what the ideal way to do this is in Python. From the Zen of

Answer 1

This is a PHP function I wrote about a week ago which checks if two words are anagrams. How would this compare (if implemented the same in python) to the other methods suggested? Comments?

public function is_anagram($word1, $word2) {
    $letters1 = str_split($word1);
    $letters2 = str_split($word2);
    if (count($letters1) == count($letters2)) {
        foreach ($letters1 as $letter) {
            $index = array_search($letter, $letters2);
            if ($index !== false) {
                unset($letters2[$index]);
            }
            else { return false; }
        }
        return true;
    }
    return false;        
}

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Here's a literal translation to Python of the PHP version (by JFS):

def is_anagram(word1, word2):
    letters2 = list(word2)
    if len(word1) == len(word2):
       for letter in word1:
           try:
               del letters2[letters2.index(letter)]
           except ValueError:
               return False               
       return True
    return False

Comments:

    1. The algorithm is O(N**2). Compare it to @namin's version (it is O(N)).
    2. The multiple returns in the function look horrible.