Python Method in a Class

Question

I'm trying to start using objects properly, I've built a deck of cards which is my object. I want to be able shuffle and deal cards from it. However I can't figure out how to get the shuffle method to work correctly or even if this is the best way to do it.

import itertools
import random
class Deck:
 '''Deck of cards to be used in a card game'''
 def __init__(self):
 self.faces = ['A', 'K', 'Q', 'J', 'T', '9', '8', '7', '6', '5', '4','3', '2']
 self.suits = ['c', 'd', 'h', 's']
 self.cards = set(itertools.product(self.faces, self.suits))
 def shuffle(self):
 self.cards = random.shuffle(self.cards)
 def deal(self):
 card = self.cards.pop()
 return card[0] + card[1]

Usage;

deck = Deck()
deck.shuffle()
deck.deal()

• DirtyBit: Should be using list instead of set.
• chepner: random.shuffle modifies a list in-place; it returns None, not the shuffled list.
• Rhys: List and shuffle in place works. Thanks guys

Answer 1

Sets are not ordered, you could use list() to obtain an ordered deck. Furthermore random.shuffle(l) acts directly on the list and returns None, so you are overwriting the list with None.

import itertools
import random
class Deck:
 '''Deck of cards to be used in a card game'''
 def __init__(self):
 self.faces = ['A', 'K', 'Q', 'J', 'T', '9', '8', '7', '6', '5', '4','3', '2']
 self.suits = ['c', 'd', 'h', 's']
 self.cards = list(itertools.product(self.faces, self.suits)) # ordered deck
 # self.cards = set(itertools.product(self.faces, self.suits)) # unordered deck
 def shuffle(self):
 random.shuffle(self.cards)
 def deal(self):
 card = self.cards.pop()
 return card[0] + card[1]

• chepner: There's no need for set at all, as product isn't going to produce any duplicates that need to be removed.
• dzang: it needs only one between list or set. It didn't need list(set( ... )), thanks for pointing it out