为什么我写的其余代码不起作用？

Question

我想将这个原始代码更改为我的想法，

num1 = float(input('enter your first number :'))
op = input('choose your operator: ')
num2 = float(input('enter your second number :'))


if op == '-':
    print(num1 - num2)
elif op == '+':
    print(num1 + num2)
elif op == '*':
    print(num1 * num2)
elif op == '/':
    print(num1 / num2)
else:
    print('invalid operator')

并更改为这样。 但它只显示第一个操作：-

**num1 = float(input('enter your first number :'))
op = input('choose your operator: ')
num2 = float(input('enter your second number :'))
operator = ('+', '-', '/', '*')

if op in operator:
    print(num1 - num2)
elif op in operator:
    print(num1 + num2)
elif op in operator:
    print(num1 * num2)
elif op in operator:
    print(num1 / num2)
else:
    print('invalid operator')

我试图更改第一个代码（原始代码） 到我想自己编写的第二个代码。 但它只显示第一个运算符：- 我哪里做错了？

Answer 1

我想也许你需要这个

num1 = float(input('enter your first number :'))
op = input('choose your operator: ')
num2 = float(input('enter your second number :'))

operator = {
    "-": lambda x, y: x - y,
    "+": lambda x, y: x + y,
    "/": lambda x, y: x / y,
    "*": lambda x, y: x * y
    }

if op in operator:
    print(operator[op](num1, num2))
else:
    print('invalid operator')