How do you create a randomly generated list of items while ensuring there are no duplicates?

I am trying to make a function that randomly selects items from a list and makes a new list with a random order of items every time it runs. I believe I have the bulk of it done, however, I am missing a way to make sure that when my function runs, it always generates just one of each item in the list without duplicates (excluding the intentional duplicates I made in my list, ie: I want a list of 16 items with 2 c1, c2, c3, etc but not something like 3 c1, 1 c2, 5 c3).

def random_assignment():
list_of_pairs = [c1, c1, c2, c2, c3, c3, c4, c4, c5, c5, c6, c6, c7, c7, c8, c8]
random_list = list(random.choice(list_of_pairs))
keep_generating = True
while keep_generating:
    return random_list
if len(random_list) == 16:
    keep_generating = False