input: Write a function to return the length of a given string.
  
  def get_string_length(string):
      return len(string)
  
  assert get_string_length("Python")==6
  assert get_string_length("Hello")==5
  assert get_string_length("OpenAI")==6
  assert get_string_length("")==0
  assert get_string_length("12345")==5
output: def get_string_length(string):
      return len(string)