Best way to make a list unique?

[Eric Pederson]

I have 

>>> listA=[1,2,3,4,5,4,3,4,3,2,1]

and I want a list of only the unique members.

This seems inefficient, but works fine over my small sample lists:

>>> listA=[a for a in set(listA)]


Is there a more efficient approach for cases where listA is large?






Eric Pederson
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