>>> timeit.timeit("'x' in ('x',)")0.04869917374131205>>> timeit.timeit("'x' == 'x'")0.06144205736110564 >>> timeit.timeit("'x' in ('x', 'y')")0.04866674801541748>>> timeit.timeit("'x' == 'x' or 'x' == 'y'")0.06565782838087131>>> timeit.timeit("'x' in ('y', 'x')")0.08975995576448526>>> timeit.timeit("'x' == 'y' or 'x' == 'y'")0.12992391047427532