设计模式学习-简单工厂模式（python3）

参考链接， 在Python3环境下，调试实现了《大话设计模式》中简单工厂模式，通过定义单独的工厂类，完成对具体的产品的实例化

具体实现见代码：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Date    : 2017-10-15 21:46:28
# Author  : John
# Version : V1.001
# Func    :


class Operator(object):
    """docstring for Operator"""

    def __init__(self, NumberA=0, NumberB=0):
        super(Operator, self).__init__()
        self.NumberA = NumberA
        self.NumberB = NumberB

    def GetResult(self):
        pass


class AddOp(Operator):
    """docstring for AddOp"""

    def GetResult(self):
        return int(float(self.NumberA) + float(self.NumberB))


class MinusOp(Operator):
    """docstring for MinusOp"""

    def GetResult(self):
        return int(float(self.NumberA) - float(self.NumberB))


class MultiOp(Operator):
    """docstring for MultiOp"""

    def GetResult(self):
        return int(float(self.NumberA) * float(self.NumberB))


class DivideOp(Operator):
    """docstring for DivideOp"""

    def GetResult(self):
        try:
            return float(float(self.NumberA) / float(self.NumberB) * 1.0)
        except ZeroDivisionError as e:
            print("DivideOp error, {0}".format(e))


class OperatorFactory(object):
    """docstring for OperatorFactory"""

    def ChooseOperator(self, op):
        if op == '+':
            return AddOp()
        if op == '-':
            return MinusOp()
        if op == '*':
            return MultiOp()
        if op == '/':
            return DivideOp()


if __name__ == '__main__':
    ch = ''
    while not ch == 'q':
        NumberA = input('Please input NumberA: ')
        op = input('Please input operator: ')
        NumberB = input('Please input NumberB: ')

        factory = OperatorFactory()
        opType = factory.ChooseOperator(op)
        opType.NumberA = NumberA
        opType.NumberB = NumberB

        print('The result is: {0}'.format(opType.GetResult()))
        print('
#-- input q to exit any key to continue')

        try:
            ch = str(input())
        except Exception as e:
            print('Get input error: {0}'.format(e))
            print('Use default value to ch')
            ch = ''