code: def upper_underscore(string, prefix='', suffix=''):
      
  
      return require_valid(append_underscore_if_keyword('_'.join(
          word.upper()
          for word in en.words(' '.join([prefix, string, suffix])))
      ))
docs: Generate an underscore-separated upper-case identifier.
      Useful for constants.
  
      Takes a string, prefix, and optional suffix.
  
      `prefix` can be set to `''`, though be careful - without a prefix, the
      function will throw `InvalidIdentifier` when your string starts with a
      number.
  
      Example:
          >>> upper_underscore("This is a constant", prefix='')
          'THIS_IS_A_CONSTANT'