1from itertools import permutations, combinations_with_replacement
 2
 3def empty_box(box):
 4    for car, student in box:
 5        car.remove_student(student)
 6
 7def organize(cars, students):
 8    #generate a sequence of students positions to be tested
 9    for config in list(permutations(students)):
10        # for this sequence generate a distribution of the number of students in each car
11        # x1 +x2+....+xk=n assuming len(cars)=k,len(students)=n
12        for combo in combinations_with_replacement(range(len(cars)), len(students)):
13            box = []
14            std_pos = 0
15            works = True
16            # go through the generated car positions and distribute students
17            for car_pos in combo:
18                try:
19                    cars[car_pos].add_student(students[config[std_pos]])
20                except EnvironmentError:
21                    # if reached here the combo is not a solution
22                    empty_box(box)
23                    works = False
24                    break
25                else:
26                    # if student is not OK then just stop the exploration
27                    if not students[config[std_pos]].is_comfy():
28                        empty_box(box)
29                        works = False
30                        break
31                    box.append((cars[car_pos], students[config[std_pos]]))
32                    std_pos += 1
33            if works:
34                return True
35    return False