{
  "id": "python/starlette-runtime-error-multiple-exception-handlers",
  "signature": "RuntimeError: Multiple exception handlers registered for the same exception type.",
  "signature_zh": "RuntimeError: 为同一异常类型注册了多个异常处理程序。",
  "regex": "RuntimeError:\\ Multiple\\ exception\\ handlers\\ registered\\ for\\ the\\ same\\ exception\\ type\\.",
  "domain": "python",
  "category": "config_error",
  "subcategory": null,
  "root_cause": "Two or more exception handlers are added for the same exception class (e.g., HTTPException).",
  "root_cause_type": "generic",
  "root_cause_zh": "为同一个异常类（例如 HTTPException）添加了两个或多个异常处理程序。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Removing all handlers and adding only one",
      "why_fails": "May lose custom error responses.",
      "fail_rate": 0.5,
      "condition": "",
      "sources": []
    },
    {
      "action": "Using different exception classes",
      "why_fails": "Doesn't solve duplicate registration.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Consolidate handlers into one",
      "success_rate": 0.9,
      "how": "from starlette.exceptions import HTTPException\nfrom starlette.responses import JSONResponse\nasync def custom_handler(request, exc):\n    return JSONResponse({'error': str(exc.detail)}, status_code=exc.status_code)\napp.add_exception_handler(HTTPException, custom_handler)",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use middleware instead of multiple handlers",
      "success_rate": 0.85,
      "how": "from starlette.middleware.base import BaseHTTPMiddleware\nclass ErrorMiddleware(BaseHTTPMiddleware):\n    async def dispatch(self, request, call_next):\n        try:\n            response = await call_next(request)\n        except HTTPException as exc:\n            return JSONResponse({'error': exc.detail}, status_code=exc.status_code)\n        return response",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.81,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-11-20",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}