Python设计模式(1)-简单工厂模式

为操作数据库设计增删改查操作

# coding=utf-8
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:
    dbmanager = {}
    dbmanager['Insert'] = DbInsert()
    dbmanager['Del'] = DbDel()
    dbmanager['Update'] = DbUpdate()
    dbmanager['Query'] = DbQuery()

    def create_dbmanager(self, operate):
        if operate in self.dbmanager:
            op = self.dbmanager[operate]
        else:
            op = UnDef()
        return op

if __name__ == "__main__":
    operate = raw_input("输入操作: ")
    factory = DbManagerFactory()
    fac = factory.create_dbmanager(operate)
    print fac.operate_db()