SQLAlchemy：从表名称获取模型。据我所知，这可能暗示将某些函数附加到元类构造函数中

受伊芙评论的启发：

def get_class_by_tablename(tablename):  """Return class reference mapped to table.  :param tablename: String with name of table.  :return: Class reference or None.  """  for c in base._decl_class_registry.values():    if hasattr(c, '__tablename__') and c.__tablename__ == tablename:      return c