03. Calculations

command = input()
num1 = int(input())
num2 = int(input())

def calculation():
    if command == "multiply":
        return num1 * num2
    elif command == "divide":
        if num1 != 0:
            return num1 / num2
    elif command == "add":
        return num1 + num2
    elif command == "subtract":
        return num1 - num2

print(int(calculation()))


Или с вложени функции:

command = input()
num1 = int(input())
num2 = int(input())


def calculation():
    def multiply():
        return num1 * num2

    def divide():
        if num1 != 0:
            return num1 / num2

    def add():
        return num1 + num2

    def subtract():
        return num1 - num2

    return {"multiply": multiply(), "divide": divide(), "add": add(), "subtract": subtract()}[command]


print(int(calculation()))