Simple anagram or permutation generator in Python

Question

In preparation for a job interview I decided to try and implement the classic find all anagrams of a given string solution. I wanted to see if I could translate a javascript solution into python. This was my attempt:

def anagrams(word):
    if len(word) < 2:
        return word
    else:
        tmp = []
        for i, letter in enumerate(word):
            for j in anagrams(word[:i]+word[i+1:]):
                tmp.append(j+letter)
    return tmp

if __name__ == "__main__":
    print anagrams("abc")

Answer 1

Your python code is neat, simple and easy to understand (so generally it's good); and yet, something in me doesn't like the use of so many temporary arrays. How about using a generator?

def anagrams(word):
    """ Generate all of the anagrams of a word. """ 
    if len(word) < 2:
        yield word
    else:
        for i, letter in enumerate(word):
            if not letter in word[:i]: #avoid duplicating earlier words
                for j in anagrams(word[:i]+word[i+1:]):
                    yield j+letter 

if __name__ == "__main__":
    for i in anagrams("acbcddd"):
        print i

I (now) filtered out all duplicates which is almost certain your original intention and is standard in all anagram problems. I did this by seeing if the same letter was already earlier in the word in which case we will have already generated this anagram.

You would have to do the same, or get rid of duplicates in your list for example by doing

return list(set(tmp))

instead of your current return from anagrams.