用python实现一个简单的计算器（while ture循环）

在Python中，我们可以创建一个简单的命令行计算器，利用`while True`循环持续接收用户输入并计算结果，直到用户选择退出。下面是一个基本的例子：

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

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

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

def divide(x, y):
    if y != 0:
        return x / y
    else:
        print("Error! Division by zero is not allowed.")
        return None

print("\nSimple Calculator:")
while True:
    print("1. Add")
    print("2. Subtract")
    print("3. Multiply")
    print("4. Divide")
    print("5. Exit")

    choice = input("Enter your choice (1-5): ")

    if choice == '5':
        break

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

    try:
        if choice == '1':
            result = add(num1, num2)
        elif choice == '2':
            result = subtract(num1, num2)
        elif choice == '3':
            result = multiply(num1, num2)
        elif choice == '4':
            result = divide(num1, num2)
        else:
            print("Invalid choice. Please try again.")

        print(f"Result: {result}")
    except ValueError:
        print("Invalid input. Please enter a number.")