Timing comparison of membership lookup

list_vs_dict.py

import time
from random import randint

num_items = 1000000
num_iters = 1000

randoms_list = [randint(0, 1000000) for i in range(num_items)]
randoms_dict = {num: True for num in randoms_list}
randoms_set = {num for num in randoms_list}

time_start = time.time()
for i in range(num_iters):
    # -1 is definitely not present, therefore 'in' will scan the entire list
    if -1 in randoms_list:
        pass
print("List operations in", time.time() - time_start)

time_start = time.time()
for i in range(num_iters):
    # in a dictionary, 'in' is a O(1) lookup
    if -1 in randoms_dict:
        pass
print("Dict operations in", time.time() - time_start)

time_start = time.time()
for i in range(num_iters):
    # in a set, 'in' is a O(1) lookup
    if -1 in randoms_set:
        pass
print("Set operations in", time.time() - time_start)