fastapi-exceptionshandler 0.0.2

Standardize and handle exceptions in FastAPI more elegantly

Routes Manager for FastAPI

Standardize and handle exceptions in FastAPI more elegantly.

Installation

$ pip install fastapi-exceptionshandler

Example

You can automatically handle all exceptions using fastapi-routesmanager. Simply register the APIExceptionManager to the RouteManagersRegistry. Don't forget to use the ManagedAPIRouter

Note: by default Validation errors are not captured. To do so, use APIExceptionManager(capture_validation=True) instead.

from fastapi import FastAPI

from fastapi_routesmanager import RouteManagersRegistry, ManagedAPIRouter

from fastapi_exceptionshandler import APIExceptionManager

RouteManagersRegistry.register_route_manager(APIExceptionManager)  # Register manager

app = FastAPI()

router = ManagedAPIRouter()

@router.get("/")  # Use router instead of app
def read_root():
    return 1/0


app.include_router(router)  # Include the router to the app

Or you can handle exceptions manually...

from fastapi import FastAPI

from fastapi_exceptionshandler import APIExceptionHandler

app = FastAPI()

@app.get("/")
def read_root():
    try:
        return 1/0
    except Exception as exc:
        return await APIExceptionHandler.unhandled(exc)

Create a custom exception class and error code, then

Run it

$ uvicorn main:app --reload

Check it

Browse to http://127.0.0.1:8000 you should see this json:

{"errorCode": "InternalError", "message": "Internal Server Error"}

Creating custom exceptions

In order to create a custom exception you need to extend APIException and create an Enum class.

Note: if you want to capture only APIException then use APIExceptionManager(capture_unhandled=False)

from enum import Enum

from fastapi import FastAPI

from fastapi_routesmanager import RouteManagersRegistry, ManagedAPIRouter

from fastapi_exceptionshandler import APIExceptionManager, APIException

RouteManagersRegistry.register_route_manager(APIExceptionManager)  # Register manager

app = FastAPI()

router = ManagedAPIRouter()


class CustomException(APIException):
    status_code = 401
    
    class ErrorCode(Enum):
        CustomExceptionCode = "Custom Exception Message"


@router.get("/")  # Use router instead of app
def read_root():
    raise CustomException(CustomException.ErrorCode.CustomExceptionCode)


app.include_router(router)  # Include the router to the app

Then you should get a 401 response with this body

{"errorCode": "CustomExceptionCode", "message": "Custom Exception Message"}

Or you can handle exceptions manually...

@app.get("/")
def read_root():
    try:
        raise CustomException(CustomException.ErrorCode.CustomExceptionCode)
    except APIException as exc:
        return await APIExceptionHandler.handled(exc)
    except Exception as exc:  # Handle all exceptions
        return await APIExceptionHandler.unhandled(exc)

Note: The ErrorCode class doesn't need to be inside CustomException and can be shared with another exceptions as well.