请分别用python和java两种语言编写输出一个计算器

Python代码：

# 定义加法函数
def add(x, y):
   return x + y

# 定义减法函数
def subtract(x, y):
   return x - y

# 定义乘法函数
def multiply(x, y):
   return x * y

# 定义除法函数
def divide(x, y):
   return x / y

# 输出菜单
print("选择运算：")
print("1、相加")
print("2、相减")
print("3、相乘")
print("4、相除")

# 获取用户输入
choice = input("输入你的选择（1/2/3/4）：")

num1 = float(input("输入第一个数字："))
num2 = float(input("输入第二个数字："))

# 根据用户的选择进行运算
if choice == '1':
   print(num1,"+",num2,"=", add(num1,num2))

elif choice == '2':
   print(num1,"-",num2,"=", subtract(num1,num2))

elif choice == '3':
   print(num1,"*",num2,"=", multiply(num1,num2))

elif choice == '4':
   if num2 == 0:
       print("除数不能为0")
   else:
       print(num1,"/",num2,"=", divide(num1,num2))
else:
   print("非法输入")

Java代码：

import java.util.Scanner;

public class Calculator {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        System.out.println("选择运算：");
        System.out.println("1、相加");
        System.out.println("2、相减");
        System.out.println("3、相乘");
        System.out.println("4、相除");

        int choice = scan.nextInt();

        System.out.println("输入第一个数字：");
        double num1 = scan.nextDouble();

        System.out.println("输入第二个数字：");
        double num2 = scan.nextDouble();

        switch (choice) {
            case 1:
                System.out.println(num1 + " + " + num2 + " = " + (num1 + num2));
                break;
            case 2:
                System.out.println(num1 + " - " + num2 + " = " + (num1 - num2));
                break;
            case 3:
                System.out.println(num1 + " * " + num2 + " = " + (num1 * num2));
                break;
            case 4:
                if (num2 == 0) {
                    System.out.println("除数不能为0");
                } else {
                    System.out.println(num1 + " / " + num2 + " = " + (num1 / num2));
                }
                break;
            default:
                System.out.println("非法输入");
        }
    }
}