10.6.3 Class DeckOfCards

• Class attribute NUMBER_OF_CARDS represents the number of Cards in a deck
• Data attribute _current_card keeps track of which Card will be dealt next (0–51)
• Data attribute _deck is a list of 52 Card objects

Method __init__

• Initializes a _deck of Cards
• for statement fills the list _deck by appending new Card objects, each initialized with two strings—one from the list Card.FACES and one from Card.SUITS

# deck.py
"""Deck class represents a deck of Cards."""
import random 
from card import Card

class DeckOfCards:
    NUMBER_OF_CARDS = 52  # constant number of Cards

    def __init__(self):
        """Initialize the deck."""
        self._current_card = 0
        self._deck = []

        for count in range(DeckOfCards.NUMBER_OF_CARDS):  
            self._deck.append(Card(Card.FACES[count % 13], 
                Card.SUITS[count // 13]))

Method shuffle

• Resets _current_card to 0, then shuffles the Cards in _deck using the random module’s shuffle function

def shuffle(self):
        """Shuffle deck."""
        self._current_card = 0
        random.shuffle(self._deck)

Method deal_card

• Deals one Card from _deck
• Returns None when there are no more Cards to deal

def deal_card(self):
        """Return one Card."""
        try:
            card = self._deck[self._current_card]
            self._current_card += 1
            return card
        except:
            return None

Method __str__

• Returns a string representation of the deck in four columns with each Card left aligned in a field of 19 characters

def __str__(self):
        """Return a string representation of the current _deck."""
        s = ''

        for index, card in enumerate(self._deck):
            s += f'{self._deck[index]:<19}'
            if (index + 1) % 4 == 0:
                s += '\n'

        return s

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