Python 类和方法实例化

Question

这是我的代码:

class calculator:

    def addition(x,y):
        added=x+y
        print(added)

    def subtraction(x,y):
        sub=x-y
        print(sub)

    def multiplication(x,y):
        mult=x*y
        print(mult)

    def division(x,y):
        div= x/y
        print(div)

calculator.addition(5,7)

这个程序给了我以下错误:

Traceback (most recent call last):
  File "C:/Python27/docs/defin_class.py", line 21, in <module>
    calculator.addition(6,3)
TypeError: unbound method addition() must be called with calculator instance as first argument (got int instance instead)

我不明白这个错误。请帮忙。

Answer 1

因此，无需过多关注细节，您应该在每个函数上方添加 @staticmethod 装饰器，就像我在下面所做的那样:

class calculator:

    @staticmethod
    def addition(x,y):
        added=x+y
        print(added)

    @staticmethod
    def subtraction(x,y):
        sub=x-y
        print(sub)

    @staticmethod
    def multiplication(x,y):
        mult=x*y
        print(mult)

    @staticmethod
    def division(x,y):
        div= x/y
        print(div)

calculator.addition(5,7)

原因是所有这些方法都是计算器的函数，但它们并不操作计算器类的对象。

要全面了解您应该在 Python 中使用的不同类型的方法，我强烈推荐 this blog post 。祝你好运!