objects_list : objects_list objects_def
                        | objects_def
                        | empty

def p_objects_list(self, p):
        '''objects_list : objects_list objects_def
                        | objects_def
                        | empty'''
        if len(p) == 3:
            p[1].append(p[2])
            p[0] = p[1]
        elif len(p) == 2:
            p[0] = [p[1]]