捕获多个异常

Question

我正在编写一个api。

from rest_framework import exceptions

类XYZ(APIView)：

authentication_classes = [SessionAuthentication, ]
permission_classes = [IsAuthenticated, ]
api_view = ['GET']

def get(self, request):
    try:
        payer_data = validate_payer(db=db,request =request,payer = payer,userid = userid)            
        BODY OF API
    except Exception as e:
        print("---",e)
        manager.create_from_exception(e)
        return Response(AppResponse.msg(request, 400, 'Something went wrong.', 0, 0, 0), status=status.HTTP_400_BAD_REQUEST)

def validate_payer(db,request,payer,userid):
    organisations = ReportUtils.get_payer_and_company(db,request =request,userid = userid,payer=True)
    if len(organisations) == 0:
        raise exceptions.NotAcceptable(AppResponse.msg(request, 406, 'No payer associated with the user.', 0, 0, 0))

现在我想知道如果异常是从validate引发的

_

payer函数，那么它就不应该进入XYZ(APIView)类中的except块，当由于pi的主体而发生任何其他异常时，它应该转到except块并返回错误请求。什么？

Answer 1

我们可以使用

isinstance

内置函数。

def get(self, request):
try:
    payer_data = validate_payer(db=db,request =request,payer = payer,userid = userid)            
    BODY OF API
except Exception as e:
        if isinstance(e,exceptions.NotAcceptable):
            raise
        elif isinstance(e,exceptions.PermissionDenied):
            raise
        else:
            manager.create_from_exception(e)
            return Response(AppResponse.msg(request, 400, 'Something went wrong.', 0, 0, 0), status=status.HTTP_400_BAD_REQUEST)

因此，如果异常属于NotAcceptable或PermissionDenied类，它将再次引发异常，否则将给出通用消息

出了点问题

状态码

400

Answer 2

python中的块可以有多个except子句，抛出的异常通过这些子句，直到遇到第一个匹配的子句。

对于应该重新引发(或需要其他特定处理)而不是由异常处理程序处理的单个异常，以下代码应该可以工作。

def get(self, request):
    try:
        payer_data = validate_payer(db=db,request =request,payer = payer,userid = userid)            
        # BODY OF API
    except exceptions.NotAcceptable:
        # Handle NotAcceptable.
        raise
    except Exception as e:
        # Handle all other exceptions.
        manager.create_from_exception(e)
        return Response(AppResponse.msg(request, 400, 'Something went wrong.', 0, 0, 0), status=status.HTTP_400_BAD_REQUEST

如果多个异常需要相同的异常处理程序，则可以将异常类替换为多个异常类的元组。

def get(self, request):
    try:
        payer_data = validate_payer(db=db,request =request,payer = payer,userid = userid)            
        # BODY OF API
    except (exceptions.NotAcceptable, exceptions.PermissionDenied):
        # Handle NotAcceptable and PermissionDenied.
        raise
    except Exception as e:
        # Handle all other exceptions.
        manager.create_from_exception(e)
        return Response(AppResponse.msg(request, 400, 'Something went wrong.', 0, 0, 0), status=status.HTTP_400_BAD_REQUEST

注意

：

将始终匹配从它派生的每个异常，因此它应该始终放在最后。