18.6: Add, remove, shuffle and sort
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To deal cards, we would like a method that removes a card from the deck and returns it. The list method
pop provides a convenient way to do that:
#inside class Deck: def pop_card(self): return self.cards.pop()
pop removes the last card in the list, we are dealing from the bottom of the deck.
To add a card, we can use the list method
#inside class Deck: def add_card(self, card): self.cards.append(card)
A method like this that uses another method without doing much work is sometimes called a veneer. The metaphor comes from woodworking, where a veneer is a thin layer of good quality wood glued to the surface of a cheaper piece of wood to improve the appearance.
In this case
add_card is a “thin” method that expresses a list operation in terms appropriate for decks. It improves the appearance, or interface, of the implementation.
As another example, we can write a Deck method named
shuffle using the function
shuffle from the
# inside class Deck: def shuffle(self): random.shuffle(self.cards)
Don’t forget to import
As an exercise, write a Deck method named
sort that uses the list method
sort to sort the cards in a
sort uses the
__lt__ method we defined to determine the order.