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()