用Python实现简单计算器

在Python中实现一个简单的计算器，你可以使用基本的算术运算符和用户输入功能。这里是一个基础的控制台版计算器示例：

def add(x, y):
    """加法"""
    return x + y

def subtract(x, y):
    """减法"""
    return x - y

def multiply(x, y):
    """乘法"""
    return x * y

def divide(x, y):
    """除法（需要处理除数为0的情况）"""
    if y != 0:
        return x / y
    else:
        print("Error: Division by zero is not allowed.")
        return None

print("Select operation:")
print("1.Add")
print("2.Subtract")
print("3.Multiply")
print("4.Divide")

# 用户输入
choice = input("Enter choice (1/2/3/4): ")

num1 = float(input("Enter first number: "))
num2 = float(input("Enter second number: "))

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':
    result = divide(num1, num2)
    if result is not None:
        print(num1, "/", num2, "=", result)
else:
    print("Invalid input")