My short solution…

from itertools import *
s, k = input().split()
print('\n'.join(''.join(c) 
  for c in combinations_with_replacement(sorted(s), int(k))))

from itertools import combinations_with_replacement

string,length = input().split()

for i in list(combinations_with_replacement(sorted(string),int(length))): print("".join(i))

from itertools import combinations_with_replacement

s=input().split() v=s[0].upper() k=int(s[1])

combination=combinations_with_replacement(sorted(v),k) for combo in combination: print("".join(combo))

Here is HackerRank itertools.combinations_with_replacement() in python solution - https://programmingoneonone.com/hackerrank-itertools-combinations_with_replacement-solution-in-python.html

from itertools import combinations_with_replacement

if name == 'main':

S  , r = input().split()
S = ''.join(sorted(S))


A = list(combinations_with_replacement(S , int( r)))

for i in A:

    print(''.join(i))