The Playing Cards Program 2.0

This is an example from:

Chapter 9: Python Programming for the Absolute Beginner, Third Edition - Michael Dawson.

It is a simple program that extends the previous playing cards program using inheritance.

Along with the two simple classes Card and Hand you will find a new class called Deck.

Deck represents a card deck. Interestingly if you think of a deck, it is quite like a hand, it is just a special hand that has all 52 different cards in to start with.

Hence our deck just extends (inherits) from Hand.

It then has three additional methods to the standard Hand class - populate() (populate the deck with all 52 cards), shuffle() (shuffle the card order in the list) and finally deal() which given a list of hands will deal out a number of cards to each by calling its give() method which gives a card from the deck to the other hand.

Copy the following into main.py.

import random

# Playing Cards 2.0
# Demonstrates inheritance - class extension
class Card(object):
  """ A playing card. """
  RANKS = ["A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K"]
  SUITS = ["c", "d", "h", "s"]

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

  def __str__(self):
    rep = self.rank + self.suit
    return rep


class Hand(object):
  """ A hand of playing cards. """

  def __init__(self):
    self.cards = []

  def __str__(self):
    if self.cards:
      rep = ""
      for card in self.cards:
        rep += str(card) + "\t"
    else:
      rep = "<empty>"

    return rep

  def clear(self):
    self.cards = []

  def add(self, card):
    self.cards.append(card)

  def give(self, card, other_hand):
    self.cards.remove(card)
    other_hand.add(card)


class Deck(Hand):
  """ A deck of playing cards. """

  def populate(self):
    for suit in Card.SUITS:
      for rank in Card.RANKS:
        self.add(Card(rank, suit))

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

  def deal(self, hand_list, per_hand=1):
    for rounds in range(per_hand):
      for hand in hand_list:
        if self.cards:
          top_card = self.cards[0]
          self.give(top_card, hand)
        else:
          print("Can't continue deal. Out of cards!")

def main():
    # create a deck
  deck_one = Deck()
  print("Created a new deck.")
  print("Deck:")
  print(deck_one)

  # populate the deck
  deck_one.populate()
  print("\nPopulated the deck.")
  print("Deck:")
  print(deck_one)

  # shuffle the deck
  deck_one.shuffle()
  print("\nShuffled the deck.")
  print("Deck:")
  print(deck_one)

  # create my hand
  my_hand = Hand()

  # create your hand
  your_hand = Hand()

  # create a list of hands
  hand_list = [my_hand, your_hand]

  # deal 5 cards to each of the hands in the hand_list
  deck_one.deal(hand_list, per_hand = 5)
  print("\nDealt 5 cards to my hand and your hand.")

  # print out the hands
  print("My hand:")
  print(my_hand)
  print("Your hand:")
  print(your_hand)
  print("Deck:")
  print(deck_one)

if __name__ == "__main__":
  main()

Programming in Python

The Playing Cards Program 2.0