Solve the list of elements in the arrangement and combination of this problem has been encountered a few times before without paying too much attention to the recent problems encountered quite a lot of permutations and combinations of problems, think it is necessary to review a little bit, spend some time today to write a little bit, before they are manually written, and then know that you can directly use the built-in module of the python can be accomplished this work, today the use of python's itertools module to complete this work, a total of four problems:
1. Generate an arrangement in which the elements of the list are not allowed to recur
2. Generate an arrangement, the elements in the list can be repeated
3. Generate combinations, unlimited number of elements, the elements in the list does not allow repeated occurrences
4. Generate combinations, unlimited number of elements, the elements in the list can be repeated
Because we all have the knowledge of permutations and combinations here is not burdensome, the problem is very simple, the following look at the specific implementation:
#!usr/bin/env python #encoding:utf-8 ''''' __Author__:Yishui Chancheng Function:Solving permutations and combinations of elements in lists ''' from itertools import product from itertools import combinations import itertools def test_func1(num_list): ''''' Generating permutations Elements in the list are not allowed to be repeated The number of permutations is calculated as: n!, where n is the number of elements in the num_list list ''' tmp_list = (num_list) res_list=[] for one in tmp_list: res_list.append(one) print res_list print 'Elements are not allowed to recur the total number of permutations is:', len(res_list) def test_func11(num_list): ''''' Generating permutations Elements can be repeated in the list The total number of permutations is calculated as (n*n*n... *n), a total of n n multiplied together ''' num=len(num_list) res_list=list(product(num_list,repeat=num)) print res_list print 'The total number of recurring permutations an element can have is:', len(res_list) def test_func2(num_list): ''''' Generate combinations with unlimited number of elements The elements in the list are not allowed to be repeated The number of combinations is calculated as 2^n, where n is the number of elements in the num_list. ''' res_list=[] for i in range(len(num_list)+1): res_list+=list(combinations(num_list, i)) print res_list print 'The total number of combinations in which elements are not allowed to recur is:', len(res_list) def test_func22(num_list): ''''' Generate combinations with unlimited number of elements Elements can be repeated in the list ''' 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 (*[num_list1] * i)] print res_list print 'The total number of combinations in which an element can recur is:', len(res_list) if __name__ == '__main__': num_list=[1,2,3,4] test_func1(num_list) print '-------------------------------------' test_func11(num_list) print '-------------------------------------' test_func2(num_list) print '-------------------------------------' test_func22(num_list)
The results are 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 not allowed to be repeated in the arrangement 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, 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, 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, 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, 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), (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, 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 recur in the arrangement 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 combinations in which elements are not allowed to recur is: 16 ------------------------------------- ['', '1', '2', '3', '4', '11', '12', '13', '14', '21', '22', '23', '24', '31', '32', '33', '34', '41', '42', '43', '44', '111', '112', '113', '114', '121', '122', '123', '124', '131', '132', '133', '134', '141', '142', '143', '144', '211', '212', '213', '214', '221', '222', '223', '224', '231', '232', '233', '234', '241', '242', '243', '244', '311', '312', '313', '314', '321', '322', '323', '324', '331', '332', '333', '334', '341', '342', '343', '344', '411', '412', '413', '414', '421', '422', '423', '424', '431', '432', '433', '434', '441', '442', '443', '444', '1111', '1112', '1113', '1114', '1121', '1122', '1123', '1124', '1131', '1132', '1133', '1134', '1141', '1142', '1143', '1144', '1211', '1212', '1213', '1214', '1221', '1222', '1223', '1224', '1231', '1232', '1233', '1234', '1241', '1242', '1243', '1244', '1311', '1312', '1313', '1314', '1321', '1322', '1323', '1324', '1331', '1332', '1333', '1334', '1341', '1342', '1343', '1344', '1411', '1412', '1413', '1414', '1421', '1422', '1423', '1424', '1431', '1432', '1433', '1434', '1441', '1442', '1443', '1444', '2111', '2112', '2113', '2114', '2121', '2122', '2123', '2124', '2131', '2132', '2133', '2134', '2141', '2142', '2143', '2144', '2211', '2212', '2213', '2214', '2221', '2222', '2223', '2224', '2231', '2232', '2233', '2234', '2241', '2242', '2243', '2244', '2311', '2312', '2313', '2314', '2321', '2322', '2323', '2324', '2331', '2332', '2333', '2334', '2341', '2342', '2343', '2344', '2411', '2412', '2413', '2414', '2421', '2422', '2423', '2424', '2431', '2432', '2433', '2434', '2441', '2442', '2443', '2444', '3111', '3112', '3113', '3114', '3121', '3122', '3123', '3124', '3131', '3132', '3133', '3134', '3141', '3142', '3143', '3144', '3211', '3212', '3213', '3214', '3221', '3222', '3223', '3224', '3231', '3232', '3233', '3234', '3241', '3242', '3243', '3244', '3311', '3312', '3313', '3314', '3321', '3322', '3323', '3324', '3331', '3332', '3333', '3334', '3341', '3342', '3343', '3344', '3411', '3412', '3413', '3414', '3421', '3422', '3423', '3424', '3431', '3432', '3433', '3434', '3441', '3442', '3443', '3444', '4111', '4112', '4113', '4114', '4121', '4122', '4123', '4124', '4131', '4132', '4133', '4134', '4141', '4142', '4143', '4144', '4211', '4212', '4213', '4214', '4221', '4222', '4223', '4224', '4231', '4232', '4233', '4234', '4241', '4242', '4243', '4244', '4311', '4312', '4313', '4314', '4321', '4322', '4323', '4324', '4331', '4332', '4333', '4334', '4341', '4342', '4343', '4344', '4411', '4412', '4413', '4414', '4421', '4422', '4423', '4424', '4431', '4432', '4433', '4434', '4441', '4442', '4443', '4444'] The total number of combinations in which an element can recur is: 341 [Finished in 0.4s]
summarize
The above is a small introduction to the python implementation of solving the problem of arranging and combining elements in a list, I hope to help you, if you have any questions please leave me a message, I will reply to you in time. I would also like to thank you very much for your support of my website!