Python | Permutation of a given string using inbuilt function

A permutation, also called an “arrangement number” or “order”, is a rearrangement of the elements of an ordered list S into a one-to-one correspondence with S itself. A string of length n has n! permutation. Examples:

Input :  str = 'ABC'
Output : ABC 
         ACB 
         BAC 
         BCA 
         CAB 
         CBA

We have existing solution for this problem please refer Permutations of a given string using STL link. We can also solve this problem in python using inbuilt function permutations(iterable). 

Python3

# Function to find permutations of a given string
from itertools import permutations

def allPermutations(str):

     # Get all permutations of string 'ABC'
     permList = permutations(str)

     # print all permutations
     for perm in list(permList):
         print (''.join(perm))

# Driver program
if __name__ == "__main__":
    str = 'ABC'
    allPermutations(str)

Output:

ABC
ACB
BAC
BCA
CAB
CBA

Permutation and Combination in Python Permutations of a given string with repeating characters The idea is to use dictionary to avoid printing duplicates. 

Python3

from itertools import permutations
import string

s = "GEEK"
a = string.ascii_letters
p = permutations(s)

# Create a dictionary
d = []
for i in list(p):

    # Print only if not in dictionary
    if (i not in d):
        d.append(i)
        print(''.join(i))

Output:

GEEK
GEKE
GKEE
EGEK
EGKE
EEGK
EEKG
EKGE
EKEG
KGEE
KEGE
KEEG

Time Complexity: O(n!) where n is the size of the string.
Auxiliary Space: O(n!)