How to write a function that takes a string and prints the letters in decreasing order of frequency?

Question

I got this far:

def most_frequent(string):
    d = dict()
    for key in string:
        if key not in d:
            d[key] = 1
        else:
            d[key] += 1
    return d

print most_frequent('aabbbc')

Returning:

{'a': 2, 'c': 1, 'b': 3}

Now I need to:

1. reverse the pair
2. sort by number by decreasing order
3. only print the letters out

Should I convert this dictionary to tuples or list?

Answer 1

Here's a one line answer

sortedLetters = sorted(d.iteritems(), key=lambda (k,v): (v,k))