Python port of https://github.com/xori/gamblers-dice

gamblers_fallacy.py

#!/usr/bin/env python

from __future__ import division
import random

class Die(object):
    """The Gambler's Fallacy made manifest"""
    def __init__(self, size):
        self.size = size
        self.state = [1 for i in xrange(size)]

    def roll(self):
        random_mark = random.random() * sum(self.state)
        # random_mark = random.randint(1,6)
        # print "Random mark: {}".format(random_mark)
        running_sum = 0
        result = -1
        for roll, mark in enumerate(self.state):
            # mark = self.state[roll]
            running_sum += mark
            if random_mark < running_sum and result == -1:
                result = roll
                self.state[roll] = 1
            else:
                self.state[roll] += 1
        
        return result + 1


def test():
    die = Die(6)
    result = [0,0,0,0,0,0]
    for i in xrange(1000000):
        q = die.roll() - 1
        # print q
        result[q] += 1

    average = 1000000 / 6
    randomness = [abs(i - average) / 1000000 for i in result]

    print result
    for i, r in enumerate(randomness, 1):
        print "Roll {} deviated from the average {:0.6f}% of the time".format(i, r)

if __name__ == "__main__":
    test()