Location for Django Rest framework exception handler

user_1813039 0
Viewed 2606

The DRF Docs say that once an exception handler is set up, it needs to be defined in the settings.py as follows:

REST_FRAMEWORK = {
'EXCEPTION_HANDLER': 'my_project.my_app.utils.custom_exception_handler'
}

My Django project layout is like this:

backend
    settings.py
    connectivity_service
        utils
            Custom404ErrorMessage.py

The project is called backend and the app name is connectivity_service.The Custom404ErrorMessage.py file contains the function custom_exception_handler which handles the exception.

My settings.py looks like this:

REST_FRAMEWORK = {
'EXCEPTION_HANDLER': 'backend.connectivity_service.utils.Custom404ErrorMessage'
}

However, this gives me the following error message:

ImportError: Could not import 'backend.connectivity_service.utils.Custom404ErrorMessage' 
for API setting 'EXCEPTION_HANDLER'. ModuleNotFoundError: No module named 
'backend.connectivity_service'.

What am i doing wrong ?

django-rest-framework django python
2 Answers

I had this problem too and what you need to do to solve is this:

  1. create utils.py inside your app folder
  2. define your custom_exception_handler function inside it
  3. in your setting file add this " 'EXCEPTION_HANDLER': 'my_app.utils.custom_exception_handler' ", no need to type my_project
user_179769020

My guess is that you confused the text when translating from the DRF example to your code. The docs state:

from rest_framework.views import exception_handler

def custom_exception_handler(exc, context):
# Call REST framework's default exception handler first,
# to get the standard error response.
response = exception_handler(exc, context)

# Now add the HTTP status code to the response.
if response is not None:
    response.data['status_code'] = response.status_code

return response

Then it tells you to add it to your settings as:

REST_FRAMEWORK = {
'EXCEPTION_HANDLER': 'my_project.my_app.utils.custom_exception_handler'
}

Keep in mind that the example above has the following folder structure:

my_project > my_app > utils > custom_exception_handler

Which translates to:

my_project_FOLDER > my_app_FOLDER > utils.PY > NAME_OF_DEFINED_FUNCTION_THAT_HANDLES_EXCEPTIONS

That's how I think you might have gotten confused. So you have Custom404ErrorMessage.py inside a utils_FOLDER and are trying to import that instead of the defined function itself. Unless of course that Custom404ErrorMessage.py is a class, but I doubt it since you seemed to be following the linked DRF example which uses a function.

I assume that your Custom404ErrorMessage.py has the following:

from rest_framework.views import exception_handler

def custom_exception_handler(exc, context):
....

So for your set up, your settings.py would look like this:

REST_FRAMEWORK = {
 'EXCEPTION_HANDLER': 'backend.connectivity_service.utils.Custom404ErrorMessage.custom_exception_handler'
 }

See how the last part is the defined function? Hope that helps!

user_18121820
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