设计模式之工厂模式(python实现)

看了《大话设计模式》后，深有体会，看着大婶们一个个的在搞设计模式，对于程序猿，这样的基础还是需要打打的，下面是菜鸟我用工厂模式写的python代码，不管好与劣，权且记录下来再说吧，留待以后自己万一哪天成大神后再来嘲笑自己。

#!/usr/bin/python
# coding: utf-8


class Coding(object):
    """处理编码问题"""
    def __init__(self, str_a, de_code, en_code):
        self.str_a = str_a
        self.de_code = de_code
        self.en_code = en_code

    def return_value(self):
        return self.str_a.decode(self.de_code).encode(self.en_code)


class SuperClass(object):
    """一个超级运算符类，用来继承
    """
    def __init__(self, a, b):
        pass

    def return_value(self):
        pass


class Main(object):
    """显示主界面"""
    def __init__(self):
        print Coding('----------------------', 'utf-8', 'gb2312').return_value()
        print Coding('*      计算器        *', 'utf-8', 'gb2312').return_value()
        print Coding('----------------------', 'utf-8', 'gb2312').return_value()

    def get_value_a(self):
        self.a = raw_input(Coding('左操作数>', 'utf-8', 'gb2312').return_value())

    def get_value_b(self):
        self.b = raw_input(Coding('右操作数>', 'utf-8', 'gb2312').return_value())

    def get_operation(self):
        self.operation = raw_input(Coding('操作符>', 'utf-8', 'gb2312').return_value())

    def return_result(self):
        return (self.a, self.b, self.operation)


class Add(SuperClass):
    """加运算"""
    def __init__(self, a, b):
        self.a = int(a)
        self.b = int(b)

    def return_value(self):
        return self.a+self.b


class Minus(SuperClass):
    """减运算"""
    def __init__(self, a, b):
        self.a = int(a)
        self.b = int(b)

    def return_value(self):
        return self.a-self.b


class Multi(SuperClass):
    """乘法运算"""
    def __init__(self, a, b):
        self.a = int(a)
        self.b = int(b)

    def return_value(self):
        return self.a*self.b


class Div(SuperClass):
    """除法运算"""
    def __init__(self, a, b):
        self.a = int(a)
        self.b = int(b)

    def return_value(self):
        return self.a/self.b


class Factory_calcu(object):
    """对象工厂类"""
    def __init__(self, cal, a, b):
        self.cal = cal

    def return_value(self):
        cal_obj = self.cal(a, b)
        return cal_obj



operation_dic = {'+':Add, '-':Minus, '*':Multi, '/':Div}

if __name__ == '__main__':
    main = Main()
    main.get_value_a()
    main.get_value_b()
    main.get_operation()
    a, b, operation = main.return_result()
    a = Coding(a, 'gb2312', 'utf-8').return_value()
    b = Coding(b, 'gb2312', 'utf-8').return_value()
    operation = Coding(operation, 'gb2312', 'utf-8').return_value()
    operation_obj = Factory_calcu(operation_dic[operation], a, b).return_value()
    print Coding('计算结果为：', 'utf-8', 'gb2312').return_value()
    print operation_obj.return_value()