Performance of Sets and Lists

set_vs_list

# http://stackoverflow.com/questions/2831212/python-sets-vs-lists

>>> import timeit
>>> a = set(range(1000000))
>>> b = range(1000000)
>>> def test_a():
...     '9999' in a
... 
>>> def test_b():
...     '9999' in b
... 
>>> timeit.timeit(test_a, number=1000000)
0.1480870246887207
>>> timeit.timeit(test_b, number=1000000)
# very long...