採用簡單原廠模式實現計算機（python版）

原廠模式的核心：

有這樣一群類，他們區別很小，就像運算子類，他們的區別僅僅就是不同的運算子號。這樣我們可以建一個工廠，按需“生產”出所需的所需要的類的執行個體。

#encoding=utf-8##by panda#簡單原廠模式class OperateBase():    result = 0;    def GetResult(self):        return self.result;class OperationAdd(OperateBase):    def __init__(self, NumA, NumB):        self.result = NumA + NumB;    def GetResult(self):        return self.result;            class OperationSub(OperateBase):    def __init__(self, NumA, NumB):        self.result = NumA - NumB;    def GetResult(self):        return self.result;     class OperationMult(OperateBase):    def __init__(self, NumA, NumB):        self.result = NumA * NumB;    def GetResult(self):        return self.result; class OperationDiv(OperateBase):    def __init__(self, NumA, NumB):        self.result = NumA / NumB;    def GetResult(self):        return self.result; class OperationFactory():    @staticmethod    def createOperate(operate, NumA, NumB):        optList = {        '+':OperationAdd,        '-':OperationSub,        '*':OperationMult,        '/':OperationDiv,                }        oper = OperateBase()        if(optList.has_key(operate)):            oper = optList[operate](NumA, NumB);                return operdef clientUI():    opt = raw_input("please input a operation(+-*/): ");    NumA = raw_input("please input the first number: ");    NumB = raw_input("please input the second number: ");        oper = OperationFactory.createOperate(opt, float(NumA), float(NumB))    print "Restlt: ", oper.GetResult()    returnif __name__ == '__main__':    clientUI();

UML類圖如下：