Question

I am just learning python (first language ever) and am implementing what I find in ways that I find fun. I built a pseudo slot machine odds calculator. However, it stops at one Grand prize win. Is there a way to make it run over and over to give an average number of attempts for n amount of games to get the grand prize?

Here’s my code

#!/usr/bin/env python
import random

a = 1

while a >0 :
    l1 = random.randrange(36)
    l2 = random.randrange(36)
    l3 = random.randrange(36)

    print l1, l2, l3
    if l1 == l2 == l3 == 7:
        print 'grand prize winner!!!'
        break
    elif l1 == l2 == l3:
        print 'you won! congratulations'
        print 'it took', a, 'attempts to win'
    else:
        a += 1
        print 'sorry...  try again'
        print 'attempt', a

Also, is there a way to tell me how many normal wins there were during the course of winning that grand prize

Answer 1

The break statement in the grand prize if block exits the outer while loop. If you want it to keep going, remove the break. Also, as a style point, while True: or while 1: is a bit clearer of a way to create an infinite loop. As far as the second part of your question, you have the a counter, but you may want to capture more data, like so:

import random

def play(till_jackpot_count):
    game_data_per_jackpot = [{'plays' : 0, 'wins' : 0}]
    wheel_values = xrange(36)
    wheels = [0, 0, 0]
    while till_jackpot_count >= len(game_data_per_jackpot):
        wheels = [random.choice(wheel_values) for wheel in wheels]
        game_data_per_jackpot[-1]['plays'] += 1
        print '%d plays since last jackpot' % game_data_per_jackpot[-1]['plays']
        print '%d wins since last jackpot' % game_data_per_jackpot[-1]['wins']
        print '%d total plays' % sum([data['plays'] for data in game_data_per_jackpot])
        print '%d total wins' % sum([data['wins'] for data in game_data_per_jackpot])
        print '%d total jackpots' % (len(game_data_per_jackpot) - 1)
        print 'this play: {} {} {}'.format(*wheels)
        if len(set(wheels)) == 1:
            if wheels[0] == 7:
                print 'jackpot!'
                game_data_per_jackpot.append({'plays' : 0, 'wins' : 0})
            else:
                print 'win!'
                game_data_per_jackpot[-1]['wins'] += 1
    return game_data_per_jackpot[:-1]

play(10)

I also snuck a control till_jackpot_count in at the top that will make the loop end after that number of jackpots. The function also returns the test results if you want to analyze them further outside of the function itself, but the result just gets dropped here because it is not assigned to anything.

For your own study, this code uses lists ([]), dicts ({}), tuples (()), old style string formatting ('%d' % var), new style string formatting ('{} {} {}'.format(*iterable)), list comprehensions ([a for a in b]), slicing (list[:]), and a few builtins (sum, len) in addition to the random library and while loop you’re already familiar with. I also swapped out your random.randrange() for a somewhat simpler, probably more efficient, random.sample() of a pre-built xrange().