Python设计模式(3)-工厂方法模式

# coding=utf-8

#定义一个用于创建对象的接口，让子类决定实例化哪一个类

class DbManager:
    def __init__(self):
        pass

    def operate_db(self):
        pass


class DbInsert(DbManager):
    def operate_db(self):
        print '插入操作'


class DbDel(DbManager):
    def operate_db(self):
        print '删除操作'


class DbUpdate(DbManager):
    def operate_db(self):
        print '更新操作'


class DbQuery(DbManager):
    def operate_db(self):
        print '查询操作'


class UnDef(DbManager):
    def operate_db(self):
        print '未实现'
        return 0


class DbManagerFactory:
    def createdbmanagerfactory(self):
        manager = DbManager()
        return manager


class InsertFactory(DbManagerFactory):

    def createdbmanagerfactory(self):
        manager = DbInsert()
        return manager


class DelFactory(DbManagerFactory):

    def createdbmanagerfactory(self):

        manager = DbDel()
        return manager


if __name__ == "__main__":
    fac = InsertFactory()
    fa = fac.createdbmanagerfactory()
    print fa.operate_db()