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处理函数中的多个异常[已关闭]

exception-handling error-handling exception python-3.x python

jpp · 技术社区 · 7 年前

http.server 调用函数 translate() in方法 do_GET() 这样地:

class httpd(BaseHTTPRequestHandler):
    def do_GET(self):
        self.wfile.write(bytes(f'{translate(var[0])}', 'utf-8'))

现在在这里 翻译() 函数我有几个条件语句和 try except 大致如下所示:

def translate(param):
    try:
        # do something
    except SomeError as some_err:
        print("Error: " % some_err)
        return ""

    if True:
        try:
            # do something
        except SomeOtherError as some_other_err:
            print("Error: " % some_other_err)
            return ""
        except SomeThirdError as some_third_err:
            print("Third error: " % some_third_err)
            return ""
    else:
        # additional try and except blocks which print an error and
        # return an empty string

有没有更容易处理的方法?具体来说,我希望:

避免通过单独的 除了
避免写多个 尝试 / 除了 语句,通常嵌套在函数中。

注: 这是一份 this now deleted question . 这篇文章的解决方案包括在下面,但其他答案是受欢迎的。

3 回复 | 直到 7 年前

Cartucho Vasyl 7 年前

我不确定是否 try 尝试 自定义块 Exception 班级。像这样:

class MyException(Exception):
    """Generic error message."""
    def __str__(self):
        return self.__doc__

class SomeError(MyException):
    """SomeError message."""
    pass

class SomeOtherError(MyException):
    """SomeOtherError message."""
    pass

class SomeThirdError(MyException):
    """SomeThirdError message."""
    pass



def translate(param):
    try:
        # do something
        ...
        if cond1:
            raise SomeError()
        ...
        if cond2:
            raise SomeOtherError()
        ...
        if cond3:
            raise SomeThirdError()
        ...

    except MyException as err:
        print(err)
        return ""

jpp 7 年前

怎么样 contextmanager

由于不同的操作需要处理不同的错误,因此可以使用多个 with

下面是一个人为的例子:

from contextlib import contextmanager

@contextmanager
def error_handling(msg, *exceptions):
    try:
        yield
    except exceptions as my_error:
        print(msg[my_error.__class__], my_error)
        return ''

def do_stuff(d, key, index):

    custom_msg = {IndexError: 'You have an Index Error!',
                  KeyError: 'You have a Key Error!'}

    with error_handling(custom_msg, IndexError, KeyError):
        return d[key][index]

# example prints "You have an Index Error! list index out of range"; then returns ''
do_stuff({'a': [0, 1, 2]}, 'a', 10)

Ali Kargar 7 年前

我们来定义一个函数,它有一个包含所有错误和响应的字典。在这种情况下,您可以捕获一次异常并将其发送给处理程序

更新:

def handle (e) :

exp = {'IOError' : 'NO such a file in dir ...! ' ,
       'KeyboardInterrupt' : 'Exiting ... (Keyboard interruption)',
       'IndexError' : ' a sequence subscript is out of range' ,
       'NameError' : 'a local or global name is not found'}

for key , value in exp.items() :
    if e == key :
        print (value) #or do whatever you want

def test() :
    try :
        f = open('no-file' , 'r')
    except Exception as e :
        handle (type(e).__name__)


if __name__ == "__main__" :
    test()