Three Cards Trick - Assigning random number to the cards

Question

At first I have three cards like this:

 ___    ___    ___
|   |  |   |  |   | 
| A |  | A |  | Q |
|___|  |___|  |___|

and then I shuffle them to this:

 ___    ___    ___
|   |  |   |  |   |
| 1 |  | 2 |  | 3 |
|___|  |___|  |___|

So now I want to write a function that generates a random number between 1 and 3 and assign it to be the value of the Q card. For example if I generate number 2, the cards when turned around will have this order:

 ___    ___    ___
|   |  |   |  |   |
| A |  | Q |  | A |
|___|  |___|  |___|

So I came up with a code like this

def CreateCard(card):
    print (' _____')
    print ('|     |')
    print ('|  ',card,'  |',sep='')
    print ('|_____|')

def shuffle():
    Q = random.randint(1,4)
    if Q == 1:
        cards = ['Q','A','A']
    elif Q == 2:
        cards = ['A','Q','A']
    else:
        cards = ['A','A','Q']
    return cards
for card in shuffle():
   CreateCard(card)

I guess what I'm asking is this the optimal way since I don't think I'm allowed to use any other function of random module besides randint or randrange.

Answer 1

Style

The name CreateCard is pretty bad. One would expect it to create a card and return it.

Making things easier to change

At the moment, if you ever want to use 4 or 5 cards instead of 3, you have to update code in multiple places : Q = random.randint(1,HERE), cards = HERE (3 times) and add tests like elif Q == VALUE:. This is just too easy to get wrong.

Even assuming you can only use randint, you have various ways to achieve what you are doing in a less repetitive way. First idea would be to tell that once you've generated the position for Q with q_pos = random.randint(1,nb_cards), you know you have q_pos -1 'A' cards before it and nb_cards - q_pos after.

This becomes :

def shuffle(nb_cards):
    q_pos = randint(1,nb_cards)
    return ['A'] *  (q_pos -1) + ['Q'] + ['A'] * (nb_cards - q_pos)

A different strategy would be to create a list of 'A's and just put Q somewhere.

def shuffle(nb_cards):
    cards = ['A'] * nb_cards
    q_pos = randint(0,nb_cards-1)
    cards[q_pos] = 'Q'
    return cards

Answer 2

import random

def ShowCards(cards):
    print (' ___    ___    ___')
    print ('|   |  |   |  |   |')
    print ('| %s |  | %s |  | %s |' % (cards[0], cards[1], cards[2]))
    print ('|___|  |___|  |___|')

cards = ['A', 'A', 'Q']  # Generate list with cards
random.shuffle(cards)  # Randomly reorder the cards    
ShowCards(cards)    # Print cards random order

Output:

 ___    ___    ___
|   |  |   |  |   |
| A |  | A |  | Q |
|___|  |___|  |___|