Built-in Modules Time module Using time.time() to count how long something takes import time start = time.time() for i in range(10000): continue new_time = time.time() total_time = new_time - start print(total_time) Using time.sleep(n) to wait for n seconds import time start = time.time() time.sleep(10) end = time.time() print(start - end) Random Module Generate a random number between 0 and 1 import random num = random.random() print("the random number is {}".format(num)) Generate a random number between two integers import random num = random.randint(5, 100) print("the random integer between 5 and 100 is {}".format(num)) Select a random item from a list import random my_pets = ['euclid', 'leta'] fav_pet = random.choice(my_pets) print("My randomly chosen favorite pet is {}".format(fav_pet))