python config_error ai_generated true

RuntimeError: Multiple exception handlers registered for the same exception type.

ID: python/starlette-runtime-error-multiple-exception-handlers

Also available as: JSON · Markdown · 中文
80%Fix Rate
81%Confidence
0Evidence
2024-11-20First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

Two or more exception handlers are added for the same exception class (e.g., HTTPException).

generic

中文

为同一个异常类（例如 HTTPException）添加了两个或多个异常处理程序。

Workarounds

  1. 90% success Consolidate handlers into one 
    from starlette.exceptions import HTTPException
from starlette.responses import JSONResponse
async def custom_handler(request, exc):
    return JSONResponse({'error': str(exc.detail)}, status_code=exc.status_code)
app.add_exception_handler(HTTPException, custom_handler)
  2. 85% success Use middleware instead of multiple handlers 
    from starlette.middleware.base import BaseHTTPMiddleware
class ErrorMiddleware(BaseHTTPMiddleware):
    async def dispatch(self, request, call_next):
        try:
            response = await call_next(request)
        except HTTPException as exc:
            return JSONResponse({'error': exc.detail}, status_code=exc.status_code)
        return response

Dead Ends

Common approaches that don't work:

  1. Removing all handlers and adding only one 50% fail

    May lose custom error responses.

  2. Using different exception classes 60% fail

    Doesn't solve duplicate registration.