如何在不将错误处理写入函数的情况下创建自定义错误处理类

这个 try 块不会生成异常,因为表达式计算为真/假,而且奇数/偶数检查逻辑错误。

class Error(Exception):
    pass

class UserError(Error):
    @classmethod
    def handle_even(cls, number):
        if number % 2 != 0:
            raise Error('error: odd number\n')

        return number

    @classmethod
    def handle_odd(cls, number):
        if number % 2 == 0:
            raise Error('error: even number\n')

        return number


def take_even(number):
    print(number) # if user input is bad, this won't execute

def take_odd(number):
    print(number) # if user input is bad, this won't execute

# This will raise an 'Error' exception (error: odd number)
take_even(UserError.handle_even(5))

# This will raise an 'Error' exception (error: even number)
take_odd(UserError.handle_odd(4))

你可以处理这些具体的 Error 例外情况如下:

try:
    take_even(UserError.handle_even(5))
except Error as e:
    print(e) # print 'error: odd number'

try:
    take_odd(UserError.handle_odd(4))
except Error as e:
    print(e) # print 'error: even number'

编辑: 根据@nathanv_“rzemnieks建议将方法更改为类方法。