Assignment 9

Problems

  1. A little class of your own

    Write a Coin class that will enable this code to run,

    # Your class goes here...

if __name__ == '__main__':
    coin = Coin()
    print 'Your first coin is a %s.' % (coin)

    purse = [coin]
    print 'Adding four more coins to your purse...'
    for i in range(4):
        coin = Coin(random.choice([1,5,10,25,100,200]))
        purse.append(coin)

    print 'In your purse you now have:'
    for coin in purse:
        print '\ta', coin

    total = 0
    for coin in purse:
        total += coin.value
    print 'The total value of the coins in your purse is', total, 'cents.'

    print 'Flipping your coins you get:',
    for coin in purse:
        print coin.flip(),

    and produce this output,

    >>> 
Your first coin is a Penny.
Adding four more coins to your purse...
In your purse you now have:
	  a Penny
	  a Loonie
	  a Penny
	  a Dime
	  a Quarter
The total value of the coins in your purse is 137 cents.
Flipping your coins you get: Tails Tails Tails Heads Tails
>>>

    Of course due to their random selection the exact coins that end up in the purse will vary from run to run, though the first coin created in the test above should always be a Penny, i.e. the default Coin to create is a Penny.

  2. Extending a class 1

    Extend the code in playing_cards_4.py so we can find out if a five card poker hand is a flush, i.e. all cards are from the same suit. Here's the specification code to add to the end of the module,

    if chris.is_flush():
    print 'That is a flush!'
else:
    print 'Sorry, no flush.'

  3. Extending a class 2

    Sometimes during the course of a card game we might want or need to verify that the deck is not corrupted, for example that it does not have any extra Aces in it. Extend the code in playing_cards_4.py so we can check that a deck is fair.

    Here's the specification code to add to the end of the module,

    if d.is_fair():
    print 'The deck is fair.'
else:
    print 'Uh oh, this deck is unfair.'

    Include the tests you used to determine that your method was working correctly in the code you submit.

  4. An alternative playing card representation

    Many OO programmers would look at the playing card classes developed in this module and shout,

    "Wait a minute! Actual physical playing cards have two attributes, their suit and their face value. That means your Card objects should have two attributes too that match the physical attributes, not this sketchy card number thing that encodes the values of the actual attributes in an opaque way."

    And you know, they might be right. Modify the module playing_cards_4.py to use Card objects with a pair of attributes. Name the attributes suit and face_value.

    Hint1: You shouldn't change anything after the if __name__ == '__main__': statement. Remember that one of the goals of encapsulation is to be able drop in a new class implementation for an older one without having to rewrite any code that uses it.

    Hint2: You don't have to rewrite that much of the code above the if either. Think carefully about what needs to change.

Logistics