how to randomly add a new character to a string python code example

Example 1: python random string

import secrets 
secrets.token_hex(nbytes=16)

# this will produce something like 
# aa82d48e5bff564f3221d02194611c13

Example 2: python get random character from string

import random

#String
string = "abcdefghijklmnopqrstuvwxyz"
array = []
for c in string:
  array += [c]
 
print(array[random.randint(0, len(array)-1)])

# Faster and more efficient
random.choice(string)