python, convert a dictionary to a sorted list by value instead of key

Question

I have a collections.defaultdict(int) that I\'m building to keep count of how many times a key shows up in a set of data. I later want to be able to sort it (obviously by turnin

Answer 1

If you're using the newest python 2.7 alpha, then you can use the Counter class in collections module:

c = Counter()

c['someval'] += 1
c['anotherval'] += 1
c['someval'] += 1

print c.most_common()

prints in the correct order:

[('someval', 2), ('anotherval', 1)]

The code used on 2.7 is available already and there's a version adapted to 2.5. Perhaps you want to use it to stay forward compatible with the native stdlib version that is about to be released.