Python's Simple engineering model implementation

Recently saw the next big talk design mode, decided to use Python to try to achieve the next.

Basic class

1 class operationbase (): 2     """ 3     base Operations class 4     """ 5     result = 06     def  GetResult (self):7         return Self.result

Inheriting classes

1 classOperationadd (operationbase):2     """3 addition class, inheriting base operation class4     """5     def __init__(self,numa,numb):6Self.result = NumA +NumB7     defGetResult (self):8         returnSelf.result9 Ten classoperationsub (operationbase): One     """ A subtraction Operation class, inheriting base operation class -     """ -     def __init__(self,numa,numb): theSelf.result = NumA-NumB -     defGetResult (self): -         returnSelf.result -  + classOperationmult (operationbase): -     """ + multiplication class, inheriting base operation class A     """ at     def __init__(self,numa,numb): -Self.result = NumA *NumB -     defGetResult (self): -         returnSelf.result -  - classOperationdiv (operationbase): in     """ - Division Operation class, inheriting the base Operation class, by the divisor of 0 exception capture control dividend cannot be 0 to     """ +     def __init__(self,numa,numb): -         Try: theSelf.result = NumA/NumB *         exceptZerodivisionerror: $             Print "the divisor cannot be 0!!! "Panax Notoginseng  -     defGetResult (self): the         returnSelf.result +  A#工厂类 the classoperationfactor (): + @staticmethod -     defcreateoperate (operate,numa,numb): $          forCaseinchswitch (operate): $             ifCase'+'): -Oper =Operationadd (numa,numb) -                  Break the             ifCase'-'): -Oper =operationsub (numa,numb)Wuyi                  Break the             ifCase'*'): -Oper =Operationmult (numa,numb) Wu                  Break -             ifCase'/'): AboutOper =Operationdiv (numa,numb) $                  Break -         returnOper -  - if __name__=='__main__': Aopt = Raw_input ("Please enter an operator (+-*/):") +     Try: theNumA = Float (raw_input ("Please enter a number for the first operation:")) -NumB = Float (raw_input ("Please enter a number for the second operation:")) $     exceptValueError: the         Print "Enter the wrong number, please re-enter! " theNumA = Float (raw_input ("Please enter a number for the first operation:")) theNumB = Float (raw_input ("Please enter a number for the second operation:")) the  -Oper =operationfactor.createoperate (Opt,float (NumA), float (NumB)) in     Print "Result =", Oper. GetResult ()

The case can refer to my other blog

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

Python's Simple engineering model implementation