Есть способ без ста грамм разобраться в этом алгоритме?

Все возможные перестановки 1 2 3 через рекурсию. Код после этих МНОГАБУКФФ
(1, 'not in a')
('iter', 1)
('a is', [])
('a before recursion call is', [])
(1, ' in a. Loop is over')
(2, 'not in a')
('iter', 2)
('a is', [1])
('a before recursion call is', [1])
(1, ' in a. Loop is over')
(2, ' in a. Loop is over')
(3, 'not in a')
('iter', 3)
('a is', [1, 2])
('a before recursion call is', [1, 2])
('RESULT', [1, 2, 3])
('a after recursion call is', [1, 2])
('a after recursion call is', [1])
(3, 'not in a')
('iter', 3)
('a is', [1])
('a before recursion call is', [1])
(1, ' in a. Loop is over')
(2, 'not in a')
('iter', 2)
('a is', [1, 3])
('a before recursion call is', [1, 3])
('RESULT', [1, 3, 2])
('a after recursion call is', [1, 3])
(3, ' in a. Loop is over')
('a after recursion call is', [1])
('a after recursion call is', [])
(2, 'not in a')
('iter', 2)
('a is', [])
('a before recursion call is', [])
(1, 'not in a')
('iter', 1)
('a is', [2])
('a before recursion call is', [2])
(1, ' in a. Loop is over')
(2, ' in a. Loop is over')
(3, 'not in a')
('iter', 3)
('a is', [2, 1])
('a before recursion call is', [2, 1])
('RESULT', [2, 1, 3])
('a after recursion call is', [2, 1])
('a after recursion call is', [2])
(2, ' in a. Loop is over')
(3, 'not in a')
('iter', 3)
('a is', [2])
('a before recursion call is', [2])
(1, 'not in a')
('iter', 1)
('a is', [2, 3])
('a before recursion call is', [2, 3])
('RESULT', [2, 3, 1])
('a after recursion call is', [2, 3])
(2, ' in a. Loop is over')
(3, ' in a. Loop is over')
('a after recursion call is', [2])
('a after recursion call is', [])
(3, 'not in a')
('iter', 3)
('a is', [])
('a before recursion call is', [])
(1, 'not in a')
('iter', 1)
('a is', [3])
('a before recursion call is', [3])
(1, ' in a. Loop is over')
(2, 'not in a')
('iter', 2)
('a is', [3, 1])
('a before recursion call is', [3, 1])
('RESULT', [3, 1, 2])
('a after recursion call is', [3, 1])
(3, ' in a. Loop is over')
('a after recursion call is', [3])
(2, 'not in a')
('iter', 2)
('a is', [3])
('a before recursion call is', [3])
(1, 'not in a')
('iter', 1)
('a is', [3, 2])
('a before recursion call is', [3, 2])
('RESULT', [3, 2, 1])
('a after recursion call is', [3, 2])
(2, ' in a. Loop is over')
(3, ' in a. Loop is over')
('a after recursion call is', [3])
(3, ' in a. Loop is over')
('a after recursion call is', [])