"""
 craps.py

 Find the odds of winning at craps.
  
   craps:
    a) first roll 2 dice
    b)  if sum of dice is 2, 3, or 12 => lose
    c)  if sum of dice is 7 or 11 => win
    d)  otherwise, the value is the "point"
    e) following rolls
    f)  if sum is 7 => lose
    e)  if sum is "point" => win
    g)  keep rolling

 Class exercise for intro python.

 Jim Mahoney | March 2018
"""
import random

def two_dice():
    """ return sum of rolling two dice """
    return random.randint(1,6) + random.randint(1,6)

def win_craps(verbose=False):
    """ return True if we win one game of craps """
    first_roll = two_dice()
    if verbose:
        print("")
        print("- craps -")
        print("first roll is {}".format(first_roll))
    if first_roll in (7, 11):
        if verbose:
            print("1st win!")
        return True
    elif first_roll in (2, 3, 12):
        if verbose:
            print("1st lose!")
        return False
    else:
        while True:
            next_roll = two_dice()
            if verbose:
                print("next roll is {}".format(next_roll))
            if next_roll == 7:
                if verbose:
                    print("lose!")
                return False
            elif next_roll == first_roll:
                if verbose:
                    print("win!")
                return True

def count_wins(plays = 1000000):
    print("Playing craps {} times.".format(plays))
    count = 0
    for i in range(plays):
        if win_craps():
            count = count + 1
    print("Number of wins = {}.".format(count))
    print("Odds of winning are {}.".format(float(count)/plays))

count_wins()