Question

I have a list that contains multiple repeated items. I’m trying to sort the list by giving items with the most repetitions priority.

So it would turn this

['a', 'b', 'c', 'a', 'b', 'a', 'd']

into this

['a', 'a', 'a', 'b', 'b', 'c', 'd']

Answer 1

>>> from collections import Counter
>>> [k for k,v in Counter(['a', 'b', 'c', 'a', 'b', 'a', 'd']).most_common() for i in xrange(v)]
['a', 'a', 'a', 'b', 'b', 'c', 'd']

This is possibly easier to follow

>>> counter = Counter(['a', 'b', 'c', 'a', 'b', 'a', 'd'])
>>> sorted(counter.elements(), key=counter.get, reverse=True)
['a', 'a', 'a', 'b', 'b', 'c', 'd']