#!/usr/bin/env python3
 from random import shuffle, randrange

 class Door(object):
     def __init__(self,prize):
         self.prize = prize

 class Show(object):
     def __init__(self):
         self.picked    = None
         self.revealed  = None
         self.alternate = None

           # hide prize behind random door
         self.prizes = [1,0,0]
         shuffle(self.prizes)

         self.doors = []
         for prize in self.prizes:
             self.doors.append(Door(prize))

     def pick(self):
           # candidate picks a door
         idx = randrange(0,len(self.doors))
         self.picked = idx

     def reveal(self):
           # moderator reveals another door
         for idx,door in \
                 enumerate(self.doors):
             if door.prize or \
                     self.picked == idx:
                 continue
             if self.revealed is None:
                 self.revealed = idx
           # determine remaining door
         for idx,door in \
                 enumerate(self.doors):
             if self.picked != idx and \
                     self.revealed != idx:
                 self.alternate = idx

     def prize_idx (self):
         for idx,door in \
                 enumerate(self.doors):
             if door.prize:
                 return idx

 print("picked,revealed,alternate,prize");

 for i in range(1000):
     show = Show()
     show.pick()
     show.reveal()

     print("{0},{1},{2},{3}".format(
         show.picked, show.revealed,
         show.alternate,show.prize_idx()))