Take a list, sort by popularity and then remove duplicates [duplicate]

Question

Possible Duplicate:
In python, how do I take the highest occurrence of something in a list, and sort it that way?

Hi all,

I am looking for an easy way to sort a list by popularity and then remove duplicate elements.

For example, given a list:

[8, 8, 1, 1, 5, 8, 9]

I would then end up with a list like the following:

[8, 1, 5, 9]

Answer 1

>>> lst = [1, 1, 3, 3, 5, 1, 9]
>>> from collections import Counter
>>> c = Counter(lst)
>>> [i for i, j in c.most_common()]
[1, 3, 5, 9]

see collections.Counter docs for the links to legacy versions-compatible implementations.