Python solves the problem of arrangement and combination of elements in the list.

Python solves the problem of arrangement and combination of elements in the list.

I have not paid too much attention to the problem of element arrangement and combination in the list before. I recently encountered a lot of arrangement and combination problems when I was doing the question. I want to discuss it as necessary, today, I will spend some time writing it. It was previously written manually. Later I learned that I can use python's built-in modules to complete this task. Today I will use python's itertools module to complete this task, A total of four problems are solved:

1. generate an arrangement. The elements in the list cannot appear repeatedly.

2. generate an arrangement. Elements in the list can be repeated.

3. Generate a combination with no limit on the number of elements. The elements in the list cannot be repeated.

4. Generate a combination with no limit on the number of elements. The elements in the list can be repeated.

Because everyone has the knowledge of arrangement and combination, the problem is very simple. The specific implementation is as follows:

#! Usr/bin/env python # encoding: UTF-8 ''' _ Author __: features of the city: solve the Problem of element arrangement and combination in the list ''' from itertools import product from itertools import combinations import itertools def test_func1 (num_list ): ''''' the number of elements in the generated permutation list cannot be repeated. Calculated as: n !, N is the number of elements in the num_list list ''' tmp_list = itertools. permutations (num_list) res_list = [] for one in tmp_list: res_list.append (one) print res_list print 'elements cannot repeat the total number of columns:', len (res_list) def test_func11 (num_list): ''' the total number of elements in the generated permutation list that can be repeated is calculated as: (n * n... * n), a total of n multiplied by ''' num = len (num_list) res_list = list (product (num_list, repeat = num )) print res_list print 'can be repeated. The total number of columns is', len (res_list) def test_func2 (num_list): ''' to generate a combination, in the list of unlimited number of elements, repeated combinations of elements are not allowed. Calculated as follows: 2 ^ n, where n is the number of elements in the num_list list ''' res_list = [] for I in range (len (num_list) + 1): res_list + = list (combinations (num_list, I )) print res_list print 'cannot be repeated. The total number of combinations is:', len (res_list) def test_func22 (num_list): ''' to generate a combination, in the list of unlimited number of elements, you can repeat '''res_list = [] num_list1 = [str (I) for I in num_list] for I in range (0, len (num_list) + 1): res_list + = [''. join (x) for x in itertools. product (* [num_list1] * I)] print res_list print 'elements can repeat the total number of combinations:', len (res_list) if _ name _ = '_ main _': num_list = [1, 2, 4] test_func1 (num_list) print '--------------------------------- 'test_func11 (num_list) print '----------------------------------- 'test_func2 (num_list) print' ------------------------------------- 'test_func22 (num_list)

The result is as follows:

[(1, 2, 3, 4), (1, 2, 4, 3), (1, 3, 2, 4), (1, 3, 4, 2), (1, 4, 2, 3), (1, 4, 3, 2), (2, 1, 3, 4), (2, 1, 4, 3), (2, 3, 1, 4), (2, 3, 4, 1), (2, 4, 1, 3), (2, 4, 3, 1), (3, 1, 2, 4), (3, 1, 4, 2), (3, 2, 1, 4), (3, 2, 4, 1), (3, 4, 1, 2), (3, 4, 2, 1), (4, 1, 2, 3), (4, 1, 3, 2), (4, 2, 1, 3), (4, 2, 3, 1), (4, 3, 1, 2), (4, 3, 2, 1)] The total number of elements that cannot be repeated is: 24 ----------------------------------- [(1, 1, 1, 1), (1, 1, 1, 2), (1, 1, 1, 3), (1, 1, 1, 4), (1, 1, 2, 1), (1, 1, 2, 2), (1, 1, 2, 3), (1, 1, 2, 4), (1, 1, 3, 1), (1, 1, 3, 2), (1, 1, 3, 3), (1, 1, 3, 4), (1, 1, 4, 1), (1, 1, 4, 2), (1, 1, 4, 3), (1, 1, 4, 4), (1, 2, 1, 1), (1, 2, 1, 2), (1, 2, 1, 3), (1, 2, 1, 4), (1, 2, 2, 1), (1, 2, 2), (1, 2, 2, 3), (1, 2, 2, 4), (1, 2, 3, 1), (1, 2, 3, 2), (1, 2, 3, 3), (1, 2, 3, 4), (1, 2, 4, 1), (1, 2, 4, 2), (1, 2, 4, 3), (1, 2, 4, 4), (1, 3, 1, 1), (1, 3, 1, 2), (1, 3, 1, 3), (1, 3, 1, 4), (1, 3, 2, 1), (1, 3, 2, 2), (1, 3, 2, 3), (1, 3, 2, 4), (1, 3, 3, 1), (1, 3, 3, 2), (1, 3, 3, 3), (1, 3, 3, 4), (1, 3, 4, 1), (1, 3, 4, 2), (1, 3, 4, 3), (1, 3, 4, 4), (1, 4, 1, 1), (1, 4, 1, 2), (1, 4, 1, 3), (1, 4, 1, 4), (1, 4, 2, 1), (1, 4, 2, 2), (1, 4, 2, 3), (1, 4, 2, 4), (1, 4, 3, 1), (1, 4, 3, 2), (1, 4, 3, 3), (1, 4, 3, 4), (1, 4, 4, 1), (1, 4, 4, 2), (1, 4, 4, 3), (1, 4, 4), (2, 1, 1, 1), (2, 1, 1, 2), (2, 1, 1, 3), (2, 1, 1, 4), (2, 1, 2, 1), (2, 1, 2, 2), (2, 1, 2, 3), (2, 1, 2, 4), (2, 1, 3, 1), (2, 1, 3, 2), (2, 1, 3, 3), (2, 1, 3, 4), (2, 1, 4, 1), (2, 1, 4, 2), (2, 1, 4, 3), (2, 1, 4, 4), (2, 2, 1, 1), (2, 2, 1, 2), (2, 2, 1, 3), (2, 2, 1, 4), (2, 2, 2, 1), (2, 2, 2), (2, 2, 2, 2, 3), (2, 2, 2, 4), (2, 2, 3, 1), (2, 2, 3, 2), (2, 2, 3, 3), (2, 2, 3, 4), (2, 2, 4, 1), (2, 2, 4, 2), (2, 2, 4, 3), (2, 2, 4, 4), (2, 3, 1, 1), (2, 3, 1, 2), (2, 3, 1, 3), (2, 3, 1, 4), (2, 3, 2, 1), (2, 3, 2, 2), (2, 3, 2, 3), (2, 3, 2, 4), (2, 3, 3, 1), (2, 3, 3, 2), (2, 3, 3, 3), (2, 3, 3, 4), (2, 3, 4, 1), (2, 3, 4, 2), (2, 3, 4, 3), (2, 3, 4, 4), (2, 4, 1, 1), (2, 4, 1, 2), (2, 4, 1, 3), (2, 4, 1, 4), (2, 4, 2, 1), (2, 4, 2, 2), (2, 4, 2, 3), (2, 4, 2, 4), (2, 4, 3, 1), (2, 4, 3, 2), (2, 4, 3, 3), (2, 4, 3, 4), (2, 4, 4, 1), (2, 4, 4, 2), (2, 4, 4, 3), (2, 4, 4), (3, 1, 1, 1), (3, 1, 1, 2), (3, 1, 1, 3), (3, 1, 1, 4), (3, 1, 2, 1), (3, 1, 2, 2), (3, 1, 2, 3), (3, 1, 2, 4), (3, 1, 3, 1), (3, 1, 3, 2), (3, 1, 3, 3), (3, 1, 3, 4), (3, 1, 4, 1), (3, 1, 4, 2), (3, 1, 4, 3), (3, 1, 4, 4), (3, 2, 1, 1), (3, 2, 1, 2), (3, 2, 1, 3), (3, 2, 1, 4), (3, 2, 2, 1), (3, 2, 2), (3, 2, 2, 3), (3, 2, 2, 4), (3, 2, 3, 1), (3, 2, 3, 2), (3, 2, 3, 3), (3, 2, 3, 4), (3, 2, 4, 1), (3, 2, 4, 2), (3, 2, 4, 3), (3, 2, 4, 4), (3, 3, 1, 1), (3, 3, 1, 2), (3, 3, 1, 3), (3, 3, 1, 4), (3, 3, 2, 1), (3, 3, 2, 2), (3, 3, 2, 3), (3, 3, 2, 4), (3, 3, 3, 1), (3, 3, 3, 2), (3, 3, 3, 3), (3, 3, 3, 4), (3, 3, 4, 1), (3, 3, 4, 2), (3, 3, 4, 3), (3, 3, 4, 4), (3, 4, 1, 1), (3, 4, 1, 2), (3, 4, 1, 3), (3, 4, 1, 4), (3, 4, 2, 1), (3, 4, 2, 2), (3, 4, 2, 3), (3, 4, 2, 4), (3, 4, 3, 1), (3, 4, 3, 2), (3, 4, 3, 3), (3, 4, 3, 4), (3, 4, 4, 1), (3, 4, 4, 2), (3, 4, 4, 3), (3, 4, 4), (4, 1, 1, 1), (4, 1, 1, 2), (4, 1, 1, 3), (4, 1, 1, 4), (4, 1, 2, 1), (4, 1, 2, 2), (4, 1, 2, 3), (4, 1, 2, 4), (4, 1, 3, 1), (4, 1, 3, 2), (4, 1, 3, 3), (4, 1, 3, 4), (4, 1, 4, 1), (4, 1, 4, 2), (4, 1, 4, 3), (4, 1, 4, 4), (4, 2, 1, 1), (4, 2, 1, 2), (4, 2, 1, 3), (4, 2, 1, 4), (4, 2, 2, 1), (4, 2, 2), (4, 2, 2, 3), (4, 2, 2, 4), (4, 2, 3, 1), (4, 2, 3, 2), (4, 2, 3, 3), (4, 2, 3, 4), (4, 2, 4, 1), (4, 2, 4, 2), (4, 2, 4, 3), (4, 2, 4, 4), (4, 3, 1, 1), (4, 3, 1, 2), (4, 3, 1, 3), (4, 3, 1, 4), (4, 3, 2, 1), (4, 3, 2, 2), (4, 3, 2, 3), (4, 3, 2, 4), (4, 3, 3, 1), (4, 3, 3, 2), (4, 3, 3, 3), (4, 3, 3, 4), (4, 3, 4, 1), (4, 3, 4, 2), (4, 3, 4, 3), (4, 3, 4, 4), (4, 4, 1, 1), (4, 4, 1, 2), (4, 4, 1, 3), (4, 4, 1, 4), (4, 4, 2, 1), (4, 4, 2, 2), (4, 4, 2, 3), (4, 4, 2, 4), (4, 4, 3, 1), (4, 4, 3, 2), (4, 4, 3, 3), (4, 4, 3, 4), (4, 4, 4, 1), (4, 4, 4, 2), (4, 4, 4, 3), (4, 4, 4, 4)] The total number of elements that can be repeatedly arranged is: 256 ----------------------------------- [(), (1,), (2 ,), (3,), (4,), (1, 2), (1, 3), (1, 4), (2, 3), (2, 4 ), (3, 4), (1, 2, 3), (1, 2, 4), (1, 3, 4), (2, 3, 4 ), (1, 2, 3, 4)] The total number of repeated combinations of elements is 16 --------------------------------------- ['', '1', '2', '3 ', '4', '11', '12', '13', '14', '21', '22', '23', '24', '31 ', '32', '33', '34', '41', '42', '43 ', '44', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123', '123 ', '20140901', '20160901', '20160901', '20160901', '20160901', '20160901'] The total number of combinations that can be repeated is: 341 [Finished in 0.4 s]

Summary

The above section describes the arrangement and combination of elements in the python implementation solution list. I hope it will help you. If you have any questions, please leave a message, the editor will reply to you in a timely manner. Thank you very much for your support for the help House website!