import random

def main():

   string = input("Enter a string: ")

   index = random.randint(0, len(string) - 1)

   character = string[index]

   print("The character at index {} is {}".format(index, character))

if __name__ == "__main__":

   main()

Приклад

Enter a string: Hello, world!

The character at index 5 is ,