Big talk involves pattern Python implementation-Simple Factory mode

Simple Factory Pattern: You are responsible for creating instances of other classes by defining a class specifically, and the instances that are created typically have a common parent class.

A simple arithmetic is implemented using the Simple Factory mode

1 #!/usr/bin/env python2 #-*-coding:utf-8-*-3 4 __author__='Andy'5 6 " "7 Liar design Mode8 Implement a calculator console program with any object-oriented language. Requires two numbers and arithmetic symbols to get results9 design mode-Simple Factory modeTen Simple Factory Pattern: You are responsible for creating instances of other classes by defining a class specifically, and the instances that are created typically have a common parent class.  One " " A  - classoperation (object): -     " " the The parent class of the arithmetic that receives the value entered by the user -     " " -     def __init__(Self, number1=0, number2=0): -SELF.NUM1 =Number1 +Self.num2 =number2 -  +     defGetResult (self): A         Pass at     Pass -  - #addition Operation class - classOperationadd (operation): -     defGetResult (self): -         returnSELF.NUM1 +self.num2 in  - #Subtraction Operation class to classOperationsub (operation): +     defGetResult (self): -         returnSELF.NUM1-self.num2 the  * #Multiply Operations Class $ classOperationmul (operation):Panax Notoginseng     defGetResult (self): -         returnSELF.NUM1 *self.num2 the  + #Division Operation Class A classOperationdiv (operation): the     defGetResult (self): +         ifSelf.num2 = =0: -             return 'the divisor cannot be 0' $         return1.0*SELF.NUM1/self.num2 $  - #Other operator Classes - classOperationundef (operation): the     defGetResult (self): -         return 'operator Error'Wuyi  the #Simple Factory class - classOperationfactory (object): Wu     defChoose_oper (self,ch): -         ifch = ='+': About             returnOperationadd () $         elifch = ='-': -             returnoperationsub () -         elifch = ='*': -             returnOperationmul () A         elifch = ='/': +             returnOperationdiv () the         Else: -             returnoperationundef () $  the if __name__=="__main__": theCH ="' the      while  notch = ='Q': theNUM1 = input ('Please enter the first value:') -oper = str (raw_input ('Please enter a arithmetic character:')) innum2 = input ('Please enter a second value:') the         #operation (NUM1,NUM2) theof =operationfactory () AboutOper_obj =Of.choose_oper (Oper) theOPER_OBJ.NUM1 =NUM1 theOper_obj.num2 =num2 the         Print 'The result of the operation is:', Oper_obj. GetResult ()

The structure of these classes is shown below:

Specifically defines a operation class as the parent class, the subtraction class inherits the Operation class, and the Operationfactory class is used to determine when to create the corresponding class

Andy
Source: http://www.cnblogs.com/onepiece-andy/
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Big talk involves pattern Python implementation-Simple Factory mode