Is there a pythonic way to sort Counter by value? If so, it is faster than this:
>>> from collections import Counter
>>> x = Counter({'a':1, 'b':2, 'c':3})
>>> sorted(x)
['a', 'b', 'c']
>>> sorted(x.items())
[('a', 1), ('b', 2), ('c', 3)]
>>> [(l,k) for k,l in sorted([(j,i) for i,j in x.items()])]
[('a', 1), ('b', 2), ('c', 3)]
>>> [(l,k) for k,l in sorted([(j,i) for i,j in x.items()], reverse=True)]
[('c', 3), ('b', 2), ('a', 1)