Simple roll sides script.

sides

# -*- coding: utf-8 -*-
"""
Created on Wed Jan 08 18:02:10 2014

@author: understar
"""
from __future__ import division
from collections import Counter
import sys
from random import randint

# Python 2/3 compatibility
if sys.hexversion >= 0x3000000:
    inp = input
    rng = range
else:
    inp = raw_input
    rng = xrange

def get_int(prompt):
    while True:
        try:
            return int(inp(prompt))
        except ValueError:
            pass

def count_double_one(sources):
    count = {}
    start = False
    gaps = 0
    for val in sources:
        if val == 1:
            if not start:
                start = True
            else:
                gaps += 1
                if count.has_key(gaps):
                    count[gaps] += 1
                else:
                    count[gaps] = 1
                gaps = 0
                #start = False
        else:
            gaps += 1
    return count

if __name__=="__main__":
    import numpy as np
    import matplotlib.pyplot as plt
    sides = get_int("How many sides does your die have? ")
    times = get_int("How many times do you want to roll? ")
    sources = [randint(1, sides) for roll in rng(times)]
    results = Counter(sources)
    counts = count_double_one(sources)
    E = np.sum(np.array(counts.keys())*(np.array(counts.values())/np.sum(counts.values())))
    print 'E is %f' % E    
    plt.bar(counts.keys(),counts.values())