{
  "id": "python/flask-jsonify-circular-reference",
  "signature": "ValueError: Circular reference detected",
  "signature_zh": "值错误：检测到循环引用",
  "regex": "ValueError:\\ Circular\\ reference\\ detected",
  "domain": "python",
  "category": "data_error",
  "subcategory": null,
  "root_cause": "Attempting to serialize a Python object with circular references (e.g., self-referential ORM models or graph structures) using Flask's jsonify, which lacks a resolver for cycles.",
  "root_cause_type": "generic",
  "root_cause_zh": "使用Flask的jsonify序列化具有循环引用的Python对象（如自引用ORM模型或图结构）时，jsonify没有处理循环的解析器，导致抛出循环引用错误。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "json.dumps with default=str only converts non-serializable objects to strings, but circular references cause infinite recursion before reaching that fallback.",
      "fail_rate": 0.95,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Using Flask's app.json_encoder with a custom encoder does not automatically handle circular references; it still recurses infinitely unless explicitly checked.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.9,
      "how": "Use a custom JSON encoder that tracks visited objects, or convert to a serializable dict by breaking cycles first. Example: `def serialize(obj, seen=None): if id(obj) in seen: return None; seen.add(id(obj)); return {k: serialize(v, seen) for k, v in obj.__dict__.items()}`",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.85,
      "how": "Use a library like `flask-marshmallow` or `marshmallow` with `fields.Nested` and `exclude` to avoid cycles.",
      "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": 0.85,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-03-15",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}