{
  "id": "python/pydantic-model-frozen-assignment",
  "signature": "pydantic_core._pydantic_core.ValidationError: 1 validation error for Config\nfield_name\n  Instance is frozen [type=frozen_instance, input_value='new', input_type=str]",
  "signature_zh": "pydantic_core._pydantic_core.ValidationError: 1 个验证错误 (Config)\nfield_name\n  实例已冻结 [type=frozen_instance, input_value='new', input_type=str]",
  "regex": "pydantic_core\\._pydantic_core\\.ValidationError:\\ 1\\ validation\\ error\\ for\\ Config\\\nfield_name\\\n\\ \\ Instance\\ is\\ frozen\\ \\[type=frozen_instance,\\ input_value='new',\\ input_type=str\\]",
  "domain": "python",
  "category": "runtime_error",
  "subcategory": null,
  "root_cause": "Attempting to mutate an attribute on a model with `model_config = ConfigDict(frozen=True)`.",
  "root_cause_type": "generic",
  "root_cause_zh": "尝试修改设置了 `model_config = ConfigDict(frozen=True)` 的模型属性。",
  "versions": [
    {
      "version": "2.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "Using `setattr` bypasses type checkers but still raises at runtime.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Mutating `__dict__` directly works but breaks hashing and Pydantic invariants.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.95,
      "how": "Use `model_copy(update={'field_name': 'new'})` to produce a new instance.",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.85,
      "how": "Remove `frozen=True` if mutability is required, or use `object.__setattr__(obj, 'field_name', 'new')` as a last resort.",
      "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": 0.9,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-07-22",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}