Use the Card class as given above. Now also create a Drawpile class. A Drawpile consists of a sequence of cards. The cards are supposed to form a pile with the top card having the lowest index, and the bottom card the highest index. Implement the __len__() and __getitem__() methods. Create an add() method to add a card to the draw pile at the bottom, and a draw() method to remove the top card from a draw pile and return it. Test the class.

Assignment

Define the class Card from the previous exercise again (your submission is graded on its own, so it cannot import anything from another exercise). A card (Card) is created from a suit ('Hearts', 'Spades', 'Clubs' or 'Diamonds') and a rank (2 up to 10, 'Jack', 'Queen', 'King' or 'Ace'), an AssertionError with the message invalid card must be raised if either of them is invalid, repr reads as a Python expression that creates the same card, str describes the card in the form Ace of Hearts, and the comparison operators compare two cards on their rank alone.

Also define a class Drawpile that can be used to represent a draw pile of cards. One optional argument may be passed when creating a new draw pile (Drawpile): a list (list) of cards (Card) that make up the pile, with the top card of the pile at index 0 and the bottom card at the last index. If no argument is passed, an empty draw pile must be created.

Draw piles (Drawpile) must at least support the following operations:

• The builtin function len must return the number of cards (int) on the pile.

• Indexing a draw pile (pile[i]) must return the card (Card) at position \(i\) of the pile.

• A method add that takes a card (Card) and puts it at the bottom of the pile. The method returns no value.

• A method draw that removes the top card of the pile and returns it (Card). If the pile is empty, the value None must be returned.

• If a draw pile is passed to the builtin functions repr or str, a string (str) must be returned that reads as a Python expression that creates the same draw pile.

Example

>>> pile = Drawpile([Card('Hearts', 4), Card('Clubs', 7), Card('Spades', 'Queen')])
>>> pile
Drawpile([Card('Hearts', 4), Card('Clubs', 7), Card('Spades', 'Queen')])
>>> len(pile)
3
>>> pile[0]
Card('Hearts', 4)
>>> pile[0] < pile[2]
True
>>> pile.add(Card('Diamonds', 'Ace'))
>>> len(pile)
4
>>> pile.draw()
Card('Hearts', 4)
>>> pile
Drawpile([Card('Clubs', 7), Card('Spades', 'Queen'), Card('Diamonds', 'Ace')])

>>> empty = Drawpile()
>>> len(empty)
0
>>> empty.draw()
>>> empty.add(Card('Diamonds', 10))
>>> empty
Drawpile([Card('Diamonds', 10)])