$ python-3.5.1 -m timeit -s 'l = list(range(10**6))' -- '-1 in l'
100 loops, best of 3: 18 msec per loop
$ python-3.5.1 -m timeit -s 'd = dict.fromkeys(range(10**6))' -- '-1 in d'
10000000 loops, best of 3: 0.0445 usec per loop
$ python-3.5.1 -m timeit -s 's = set(range(10**6))' -- '-1 in s'
10000000 loops, best of 3: 0.0427 usec per loop