Deck of Cards Python Classes

import random

class Card:

    suit_names = ["Clubs", "Diamonds", "Hearts", "Spades"]
    rank_names = [None, "Ace", "2", "3", "4", "5", "6", "7",
              "8", "9", "10", "Jack", "Queen", "King"]

    def __init__(self, suit, rank):
        self.suit = suit
        self.rank = rank

    def __str__(self):
        return (Card.rank_names[self.rank] + " " +
                             Card.suit_names[self.suit])

class DeckOfCard:

    def __init__(self):
        self.cards = []
        for suit in range(4):
            for rank in range(1, 14):
                card = Card(suit, rank)
                self.cards.append(card)

    def __str__(self):
        result = "\n"
        for card in self.cards:
            result += str(card) + "\n"
        return result

    def shuffle(self):
        random.shuffle(self.cards)




deck = DeckOfCard()
deck.shuffle()
print(deck)