Python Card & Deck OOP

Question

I am trying to write a program that has:

a function that creates a deck of cards, 52 by default or just 13 when a suit is provided.

AND

a function that removes the first card_count cards from the deck, returns them as a list and returns an appropriate error when out of cards.

Expected results below.

>>> deck2 = Deck('♠')
>>> deck2.shuffle_deck()
>>> print(deck2.cards)
[A of ♠, 10 of ♠, 3 of ♠, 7 of ♠, 5 of ♠, 4 of ♠, 8 of ♠, J of ♠, 9 of ♠, Q of ♠, 6 of ♠, 2 of ♠, K of ♠]

>>> deck2.deal_card(7)
[A of ♠, 10 of ♠, 3 of ♠, 7 of ♠, 5 of ♠, 4 of ♠, 8 of ♠]

>>> deck2.deal_card(7)
Cannot deal 7 cards. The deck only has 6 cards left!

My issue is I am returning an empty list each time I run my code. I think I have the first class (PlayingCard) set up right and the optional argument for suit. However, I am not quite sure how to implement the deal function or why my list is returning empty. Am I missing something small?

import random

class PlayingCard():
    def __init__(self, rank, suit):
        acc_suit = ("♠", "♥", "♦", "♣")
        acc_rank = (2, 3, 4, 5, 6, 7, 8, 9, 10, "J", "Q", "K", "A")
        assert rank in acc_rank, "Not a valid rank for a playing card."
        assert suit in acc_suit, "Not a valid suit for a playing card."
        self.suit = suit
        self.rank = rank
    
    def __repr__(self):
        return self.rank + ' of ' + self.suit

class Deck():
    
    def __init__(self, *suit):
        acc_suit = ("♠", "♥", "♦", "♣")
        self.cards = []
        if suit == None:
            for suit in range(4):
                for rank in range (1,14):
                    card = PlayingCard(rank, suit)
                    self.cards.append(card)
        if suit in acc_suit:
            for rank in range (1,14):
                card = PlayingCard(rank, suit)
                self.cards.append(card)
            

    def shuffle_deck(self):
        random.shuffle(self.cards)
    
    def deal_card(self):
        return self.cards.pop(0)
    
    
    def __str__(self):
        res = []
        for card in self.cards:
            res.append(str(card))
        return '\n'.join(res)

Answer 1

The reason your list is empty is that you never create the deck to begin with if you provide a suit. Calling

deck2 = Deck('♠')

will lead to suit = ('♠',) - a 1-tuple (containing 1 string), so it will never statisfy if suit in acc_suit: => self.deck is empty.

---

There are plenty other errors, to make your code runnable - pointed out in comments inlined:

import random

class PlayingCard():
    def __init__(self, rank, suit):
        # you try to create cards by range(2,14) but you assert that suit must
        # be 2 to 10 or "J"-"A" for picture cards
        # also: range(2,14) is [2..13] only so you miss a card
        r = {11:"J",12:"Q",13:"K",14:"A"}   
        rank = r.get(rank,rank) # translate 10 to 14 to "JQMA"

        acc_suit = ("♠", "♥", "♦", "♣")
        acc_rank = (2, 3, 4, 5, 6, 7, 8, 9, 10, "J", "Q", "K", "A")
        assert rank in acc_rank, "Not a valid rank for a playing card."
        assert suit in acc_suit, "Not a valid suit for a playing card."
        self.suit = suit
        self.rank = rank
    
    def __repr__(self):
        # can not add a string to an integer (rank is an int for 2-10 !)
        return f"{self.rank} of {self.suit}"

and your deck class:

class Deck():
    
    # change this to a named param with default so you need to supply suit=' '       
    # omit the ,* if you do not like to force suit=" " when calling this
    def __init__(self, *, suit = None):
        acc_suit = ("♠", "♥", "♦", "♣")
        self.cards = []
        if not suit:
            for suit in range(4):
                for rank in range (1,14):
                    card = PlayingCard(rank, suit)
                    self.cards.append(card)
        if suit in acc_suit:
            for rank in range (2,15):
                card = PlayingCard(rank, suit)
                self.cards.append(card)

    def shuffle_deck(self):
        random.shuffle(self.cards)
    
    # this function does not accept parameters like you posted its usage
    def deal_card(self, amount = 1):
        # always returns a list of cards, even if you only request one
        rv, self.cards = self.cards[:amount], self.cards[amount:]
        # this does NOT do the evaluation of enough cards are left, do it yourself:
        #  if len(rv) != amount: raise whatever
        return rv

    def __str__(self):
        return '\n'.join(str(c) for c in self.cards)

Test:

deck2 = Deck(suit = "♠")
print(deck2.cards)
deck2.shuffle_deck()
print(deck2.cards) 
print(deck2.deal_card(7))
print(deck2.deal_card(7))

Output:

# orignal
[2 of ♠, 3 of ♠, 4 of ♠, 5 of ♠, 6 of ♠, 7 of ♠, 8 of ♠, 9 of ♠, 10 of ♠, 
 J of ♠, Q of ♠, K of ♠, A of ♠]
# shuffeled 
[3 of ♠, 5 of ♠, 10 of ♠, 8 of ♠, A of ♠, 7 of ♠, 6 of ♠, 4 of ♠, J of ♠, 
 Q of ♠, 9 of ♠, 2 of ♠, K of ♠]
# first 7
[3 of ♠, 5 of ♠, 10 of ♠, 8 of ♠, A of ♠, 7 of ♠, 6 of ♠]
# next 7 (only 6 remain)
[4 of ♠, J of ♠, Q of ♠, 9 of ♠, 2 of ♠, K of ♠]