code: def __get_subscript(self, name, ctx=None):
      
  
      assert isinstance(name, string_types), name
      return ast.Subscript(
        value=ast.Name(id=self.data_var, ctx=ast.Load()),
        slice=ast.Index(value=ast.Str(s=name)),
        ctx=ctx)
docs: Returns `<data_var>["<name>"]`