find one combination among many? [on hold]

I have just started with Python and I am trying to make a function which generates 3 dices (using the random module) and return True if the 3 number can form 421 and return False if not.

So I need to compare the result of the 3 dices and see if it can form the number 421 so there is more than one combination. I could just write a bunch of if statement whith every combination but if the number of combination was bigger I would need something way more effective.

I tried to generate all the winning combination and put them in a list call combi_poss and compare it to a the cobination that I got call comb_d

however I can't compare this list of outcomes who by the way return that [(4, 2, 1), (4, 1, 2), (2, 4, 1), (2, 1, 4), (1, 4, 2), (1, 2, 4)] to my current combination.

This is where I'm at right now

 def alea_dice(s):
    from random import randint,seed
    from itertools import permutations
    seed(s)
    d1 = randint(1,6)
    d2 = randint(1, 6)
    d3 = randint(1, 6)
    #print(d1,d2,d3)
    solution=set([1,2,4])
    comp_d=set([d1,d2,d3])
    return comp_d == solution

   print(alea_dice(24649))

So the above code is working.

But I don't understand what the function set() is doing, and how it makes the code work.

So, if anyone has a better understanding of this, please share!