Python之簡單工程模式實現

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最近又看了下大話設計模式，決定用Python來試著實現下。

基礎類

1 class OperationBase():2     """3     基礎運算類4     """5     result = 06     def GetResult(self):7         return self.result

繼承類

 1 class OperationAdd(OperationBase): 2     """ 3     加法類，繼承基礎運算類 4     """ 5     def __init__(self,numA,numB): 6         self.result = numA + numB 7     def GetResult(self): 8         return self.result 9 10 class OperationSub(OperationBase):11     """12     減法運算類，繼承基礎運算類13     """14     def __init__(self,numA,numB):15         self.result = numA - numB16     def GetResult(self):17         return self.result18 19 class OperationMult(OperationBase):20     """21     乘法運算類，繼承基礎運算類22     """23     def __init__(self,numA,numB):24         self.result = numA * numB25     def GetResult(self):26         return self.result27 28 class OperationDiv(OperationBase):29     """30     除法運算類，繼承基礎運算類，通過被除數為0異常捕獲控制被除數不能為031     """32     def __init__(self,numA,numB):33         try:34             self.result = numA / numB35         except ZeroDivisionError:36             print "除數不能為0！！！"37 38     def GetResult(self):39         return self.result40 41 #工廠類42 class OperationFactor():43     @staticmethod44     def createOperate(operate,numA,numB):45         for case in switch(operate):46             if case(‘+‘):47                 oper = OperationAdd(numA,numB)48                 break49             if case(‘-‘):50                 oper = OperationSub(numA,numB)51                 break52             if case(‘*‘):53                 oper = OperationMult(numA,numB)54                 break55             if case(‘/‘):56                 oper = OperationDiv(numA,numB)57                 break58         return oper59 60 if __name__ == ‘__main__‘:61     opt = raw_input("請輸入一個運算操作符(+-*/)：")62     try:63         numA = float(raw_input("請輸入第一個運算的數字："))64         numB = float(raw_input("請輸入第二個運算的數字："))65     except ValueError:66         print "輸入數字不對，請重新輸入！"67         numA = float(raw_input("請輸入第一個運算的數字："))68         numB = float(raw_input("請輸入第二個運算的數字："))69 70     oper = OperationFactor.createOperate(opt,float(numA),float(numB))71     print "Result = ",oper.GetResult()

裡面的case可以參考我另外一篇部落格

http://www.cnblogs.com/ListenWind/p/4267517.html

Python之簡單工程模式實現