def switch_door(self):
    """
    Exchange the selected door to the unopened door
    """
    keys = self.keep_track["doors"].keys()
    key = keys[0] # only one door left in the collection
                  # one removed when selected. one removed when opened
    # swap the doors
    hold_this_a_second = self.keep_track["doors"][key]
    self.keep_track["doors"][key] = self.keep_track["selected"]
    self.keep_track["selected"] = hold_this_a_second
    print("\nYou now hold door %s.\n" % self.keep_track["selected"].label)

    Exchange the selected door to the unopened door
    
recipes/Python/577374_monty_hall_problem/recipe-577374.py