You can use random.sample() function in the following way:
import random
group_of_items = {1, 2, 3, 4}
num_to_select = 2
list_of_random_items = random.sample(group_of_items, num_to_select)
first_random_item = list_of_random_items[0]
second_random_item = list_of_random_items[1]