parameters: (features)
docstring: Transform a string by bracketing it with "<>". If already bracketed, does nothing.
          features: one string or a sequence of strings
          return: the gristed string, if features is a string, or a sequence of gristed strings, if features is a sequence
docstring_summary: Transform a string by bracketing it with "<>". If already bracketed, does nothing.
          features: one string or a sequence of strings
          return: the gristed string, if features is a string, or a sequence of gristed strings, if features is a sequence
docstring_tokens: Transform a string by bracketing it with < > . If already bracketed does nothing . features : one string or a sequence of strings return : the gristed string if features is a string or a sequence of gristed strings if features is a sequence
function: def add_grist (features):
      """ Transform a string by bracketing it with "<>". If already bracketed, does nothing.
          features: one string or a sequence of strings
          return: the gristed string, if features is a string, or a sequence of gristed strings, if features is a sequence
      """
  
      def grist_one (feature):
          if feature [0] != '<' and feature [len (feature) - 1] != '>':
              return '<' + feature + '>'
          else:
              return feature
      
      if isinstance (features, str):
          return grist_one (features)
      else:
          return [ grist_one (feature) for feature in features ]
function_tokens: def add_grist ( features ) : def grist_one ( feature ) : if feature [ 0 ] != '<' and feature [ len ( feature ) - 1 ] != '>' : return '<' + feature + '>' else : return feature if isinstance ( features , str ) : return grist_one ( features ) else : return [ grist_one ( feature ) for feature in features ]