python - How to delete duplicate values in a list?

Possible Duplicate:
How do you remove duplicates from a list in Python whilst preserving order?

Let us consider the list:

x = ['a', 'b', 'c', 'c', 'a', 'd', 'z', 'z']

I want to delete these duplicate values list-x and want the result as:

y = ['a', 'b', 'c', 'd', 'z']

Answer

If ordering doesn't matter, use a set:

>>> list(set(['a', 'b', 'c', 'c', 'a', 'd', 'p', 'p']))
['a', 'p', 'c', 'b', 'd']

If ordering does matter, use an OrderedDict:

>>> from collections import OrderedDict 
>>> OrderedDict.fromkeys(['a', 'b', 'c', 'c', 'a', 'd', 'p', 'p']).keys()
['a', 'b', 'c', 'd', 'p']