title: Uniformly random sampling
body: <p>My problem is as follows, I have 4 playing cards face down in front of me. There is a King, Queen, Jack, and Ace. I pick a card, look at it, then put it back face down in front of me. I'm trying to simulate picking 3 cards 1000 times (you can pick the same card multiple times) i.e. one sample of 3 can be Jack, Jack, and King. I've tried to do that here:</p>
  
  <pre><code>import random
  
  cards=["King", "Queen", "Jack", "Ace"]
  
  for i in range(1000):
      print([random.sample(cards, 3)])
  </code></pre>
  
  <p>All this does is print out 1000 iterations of picking 3 cards, but it never picks the same card twice, which it should.</p>
  
  <p>What I wanna do is count how many times I pick 3 unique cards and then calculate the probability of doing so.Then I want to calculate the average number of different cards I pick each trial. I know it will help to add values to a list, but I'm not sure how to go about it. Apologize for formatting, I'm inexperienced.</p>