{
  "id": "python/pydantic-validation-error-field-required",
  "signature": "pydantic_core._pydantic_core.ValidationError: 1 validation error for User\nname\n  Field required [type=missing, input_value={'age': 25}, input_type=dict]",
  "signature_zh": "pydantic_core._pydantic_core.ValidationError: 用户模型验证错误：name 字段缺失",
  "regex": "pydantic_core\\._pydantic_core\\.ValidationError:\\ 1\\ validation\\ error\\ for\\ User\\\nname\\\n\\ \\ Field\\ required\\ \\[type=missing,\\ input_value=\\{'age':\\ 25\\},\\ input_type=dict\\]",
  "domain": "python",
  "category": "data_error",
  "subcategory": null,
  "root_cause": "A required field is missing from the input data when instantiating a Pydantic model. In Pydantic v2, missing fields raise ValidationError instead of silently defaulting.",
  "root_cause_type": "generic",
  "root_cause_zh": "实例化 Pydantic 模型时输入数据缺少必填字段。在 Pydantic v2 中，缺失字段会抛出 ValidationError，而不是静默使用默认值。",
  "versions": [
    {
      "version": "2.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "Silently swallowing ValidationError means downstream code receives an object with missing attributes, causing AttributeError later.",
      "fail_rate": 0.85,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Pydantic v2 models are immutable by default and reject attribute assignment unless model_config allows it.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.95,
      "how": "from typing import Optional\nfrom pydantic import BaseModel\n\nclass User(BaseModel):\n    name: Optional[str] = None\n    age: int",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.98,
      "how": "user = User(name='Alice', age=25)  # include all required fields\n# or\nUser.model_validate({'name': 'Alice', 'age': 25})",
      "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": "2024-03-12",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}