Classe para um sorteio rápido :D

sorteio.py

# -*- coding: utf-8 -*-
"""
Classe para um sorteio rápido :D
run test: python -m doctest sorteio.py

>>> s = DoorPrize([1,2,3])
>>> s[0]
1
>>> s.shuffle() != [1,2,3]
True
>>> len(s)
3
>>> s.winner() in [1,2,3]
True
>>> len(s)
2
>>> s[0] in [1,2,3]
True
>>> s.winner() in [1,2,3]
True
>>> len(s)
1
>>> s[1]
Traceback (most recent call last):
    ...
IndexError: list index out of range
>>> s.winner() in [1,2,3]
True
>>> len(s)
0
>>> s[0]
Traceback (most recent call last):
    ...
IndexError: list index out of range
>>> sorted(s.winners) == [1, 2, 3]
True
>>> s = DoorPrize([1,2,2,2,3])
>>> s.list_to_sort == [1,2,3]
True
>>> [i for i in s] # test interator list_to_sort
[1, 2, 3]
"""

from random import shuffle


class DoorPrize(object):

    def __init__(self, list_to_sort=[]):
        #remove duplicity
        try:
            self.list_to_sort = list(set(list_to_sort))
        except TypeError:
            raise TypeError("Invalid list type ", list_to_sort)

        self.winners = []

    def __getitem__(self, key):
        return self.list_to_sort[key]

    def __setitem__(self, key, value):
        self.list_to_sort[key] = value

    def __len__(self):
        return len(self.list_to_sort)

    def winner(self):
        self.shuffle()
        poped = self.list_to_sort.pop()
        self.winners.append(poped)
        return poped

    def shuffle(self):
        return shuffle(self.list_to_sort)