code: def ex_literal(val):
      
      if val is None:
          return ast.Name('None', ast.Load())
      elif isinstance(val, int):
          return ast.Num(val)
      elif isinstance(val, bool):
          return ast.Name(bytes(val), ast.Load())
      elif isinstance(val, str):
          return ast.Str(val)
      raise TypeError(u'no literal for {0}'.format(type(val)))
docs: An int, float, long, bool, string, or None literal with the given
      value.