input: Write a function to print the length of a given string.
  assert print_string_length("Python") == None
  assert print_string_length("Java") == None
  assert print_string_length("JavaScript") == None
  assert print_string_length("C++") == None
  assert print_string_length("") == None
output: def print_string_length(s):
      print(len(s))