[Tutor] Silly Dice Game

[John Fouhy]

On 30/04/06, John Connors <oztriking at hotmail.com> wrote:
> The wife and I play a silly dice game and I thought it would be a good
> challange for me to write it as a program. No specific question, just
> wondering if my technique is ok and is there anything that could be done
> better. The 2 hardest things I find as a python beginner who has no real
> need to learn a programming language other than curiosity and too much spare
> time, are thinking of something to program and then knowing if what I have
> written could be done more efficiently.

Hi John,

If I were you, I would look at separating more of my program out into
functions.  Good use of functions will make your program more
readable, easier to debug, and easier to change, should the rules of
your dice game change :-)

So, your basic game structure is (correct me if I'm wrong):

while True:
    roll some dice
    check if we've won anything

The "check if we've won anything" section seems like an excellent
place to start writing functions.

For example, you have:

           #check if all dice are the same
           for fatChance in range(1,7):
               if dieList.count(fatChance) == 6:
                   score += 5000
                   dieLeft = 0
                   print "\nYou rolled all %d's, WoW!!!" % (fatChance)

           #check for a straight
           if dieList == [1,2,3,4,5,6]:
               score += 1500
               dieLeft = 0
               print "\nYou rolled a straight"

           #check for 3 pairs
           if dieLeft == 6:
               if dieList[0] == dieList[1] and dieList[2] == dieList[3] and
dieList[4] == dieList[5]:
                   score += 1500
                   dieLeft = 0
                   print"\nYou rolled three pairs"

We could change this as follows:

def checkSame(dieList):
    """ Check if all the dice are the same. """
    return len(set(dieList)) == 1

def checkStraight(dieList):
    """ Check if the die list is a straight. """
    return set(dieList) == set(range(1, 7))

def checkThreePairs(dieList):
    """ Check if the die list comprises three pairs. """
    dieList = sorted(dieList)
    return dieList[0] == dieList[1] and dieList[2] == dieList[3] and
dieList[4] == dieList[5]

These functions would go at the top of your code somewhere.  Then, we
can change your if statement to something like this:

    if checkSame(dieList):
        score += 5000
        dieLeft = 0
        print "\nYou rolled all %d's, WoW!!!" % dieList[0]
    elif checkStraight(dieList):
        score += 1500
        dieLeft = 0
        print 'You rolled a straight.'
    elif checkThreePairs(dieList):
        score += 1500
        dieLeft = 0
        print 'You rolled three pairs.'

Now, we could go even furthere here, by observing that a lot of this
is still the same.  So, maybe we could build a little data structure:

    tests = [(checkSame, 5000, 'You rolled all the same!'),
             (checkStraight, 1500, 'You rolled a straight.'),
             (checkThreePairs, 1500, 'You rolled three pairs.')]
    for test, points, message in tests:
        if test(dieList):
            score += points
            dieLeft = 0
            print message
            break

Do you understand what is going on there?

--
John.