如下所示，要求通过不同的函数来实现四则运算，该怎么做？

Question

编写程序，从键盘输入两个数字 并选择一种算术四则运算，然后输出运算结果。要求通过不同的函数来实现四则运算，并定义一个接受两个操作数和一个函数名称的函数，函数名称用于指定做哪种运算

Answer 1

import reclass OPERATION(object):def __init__(self, a, b,ys):self.a = aself.b = bself.ys=ysdef addition(self):result = self.a + self.bprint(' = %s' % result)return resultdef subtraction(self):result = self.a - self.bprint(' = %s' % result)return resultdef  multiplication (self):result = self.a * self.bprint(' = %s' % result)return resultdef division(self):if self.b==0:return print("输入有误")else:result = self.a / self.bprint(' = %s' % result)return resultdef operation(self):if self.ys is '+':OPERATION.addition(self)elif self.ys is '-':OPERATION.subtraction(self)elif self.ys is '*':OPERATION. multiplication (self)elif self.ys is '/':OPERATION.division(self)else:print("暂时没有实现这种运算")def main():print("请输要计算的算式，如 a+b 按回车键查看结果,输入exit退出")while True:str = input(">>")if str =='exit':break;else:ret = re.match(r'^(\d+)([\+\-\*/]+)(\d+)', str)if ret:numa = int(ret.group(1))operationalCharacter = ret.group(2)numb = int(ret.group(3))print(numa, operationalCharacter, numb,end='')yunsuan = OPERATION(numa, numb,operationalCharacter)yunsuan.operation()else:print("请检查输入是否正确")if __name__=='__main__':main()运行结果

Answer 2