Software Design
Spring 2006

Homework 7

Due: Wednesday 15 March

Poker!

The following are the possible hands in poker, in increasing order of value (and decreasing order of probability):

pair:

two cards with the same rank

two pair:

two pairs of cards with the same rank

three of a kind:

three cards with the same rank

straight:

five cards with ranks in sequence (aces can be high or low, but other than that, there is no wraparound).

flush:

five cards with the same suit

full house:

three cards with one rank, two cards with another

four of a kind:

four cards with the same rank

straight flush:

five cards in sequence and with the same suit

1. Type the following commands in your sd directory to download and unpack a tar file:

   wget http://wb/sd/code/poker.tgz
   tar -xzf poker.tgz
   

   It should create a directory named poker that contains the following files:

   Card.py

   : A complete version of the Card and Deck classes in the book.

   Poker.py

   : An example program that shows a graphical representation of playing cards on a `table'. You don't have to do anything with this program, but you might find it useful for debugging.

   cardsets

   : A directory containing GIF files for playing cards in a variety of styles.

   World.py, Gui.py, Lumpy.py

   : The same files you should already have.

   As always, you should take some time to familiarize yourself with the code I give you, especially Card.py.

2. Card.py includes a class named PokerHand that provides a method named has_flush that determines whether or not a hand has a flush. Add similar methods named has_pair, has_twopair, etc. that return True or False according to whether or not the hand meets the relevant criteria. Your code should work correctly for `hands' that contain any number of cards (although 5 and 7 are the most common sizes).

3. Write a method named classify that figures out the highest-value classification for a hand and sets the label attribute accordingly. For example, a 7-card hand might contain a flush and a pair; it should be labeled `flush'.

4. Write a loop that shuffles a deck of cards, divides it into hands, classifies the hands, and counts the number of times various classifications appear.

5. Print a table of the classifications and their probabilities. Run your program with larger and larger numbers of hands until the output values converge to a reasonable degree of accuracy.

6. As a JFFE, you can investigate the claim that certain hands tend to occur in clusters. For example, if you are at a table with four other players, and you have a flush, is it more likely that someone else at the table also has a flush? What about a full house?

What to turn in

1. As always, take some time to improve your code, and add comments that explain any non-obvious features.

2. Please print a copy of the complete program, and also a copy of the probability table that it outputs.