how to generate permutations of array in python?

Question

i have an array of 27 elements,and i don't want to generate all permutations of array (27!) i need 5000 randomly choosed permutations,any tip will be useful...

Answer 1

To generate one permutation use random.shuffle and store a copy of the result. Repeat this operation in a loop and each time check for duplicates (there probably won't be any though). Once you have 5000 items in your result set, stop.

To address the point in the comment, Python's random module is based on the Mersenne Twister and has a period of 2**19937-1, which is considerably larger than 27! so it should be suitable for your use.

Answer 2

import random  perm_list = []  for i in range(5000):     temp = range(27)     random.shuffle(temp)     perm_list.append(temp)  print(perm_list) 

10888869450418352160768000000 I love big numbers! :)

AND

10888869450418352160768000001 is PRIME!!

EDIT:

#with duplicates check as suggested in the comment  perm_list = set() while len(perm_list)<5000:     temp = range(27)     random.shuffle(temp)     perm_list.add(tuple(temp)) # `tuple` because `list`s are not hashable. right Beni?  print perm_list 

WARNING: This wont ever stop if RNG is bad!