Python: "in" for List v.s. Set

Both list and set are two basic data structures in Python, and they are widely used. Both data structures support the "in" statement, so either ' a in one_list: ' or ' a in one_set' is legit. However, the simulation speed differs dramatically and I will illustrate this finding with one example.

This example is a very simple options which use "not in" multiple times, from 1000, to 10000, to 100000, which mimic the 10 fold increase over N. The simulation time, for using list structure, requires almost N^2 times, while for set structure, requires almost N times. 

This suggest the "not in" operation in set is much more advantageous than the list.