{
  "id": "python/pydantic-field-required-missing",
  "signature": "pydantic_core._pydantic_core.ValidationError: 1 validation error for UserCreate\nemail\n  Field required [type=missing, input_value={'name': 'a'}, input_type=dict]",
  "signature_zh": "pydantic_core._pydantic_core.ValidationError：1 个验证错误（UserCreate）\nemail\n  字段必填 [type=missing, input_value={'name': 'a'}, input_type=dict]",
  "regex": "pydantic_core\\._pydantic_core\\.ValidationError:\\ 1\\ validation\\ error\\ for\\ UserCreate\\\nemail\\\n\\ \\ Field\\ required\\ \\[type=missing,\\ input_value=\\{'name':\\ 'a'\\},\\ input_type=dict\\]",
  "domain": "python",
  "category": "data_error",
  "subcategory": null,
  "root_cause": "The required field 'email' is absent from the input dict. In Pydantic v2 a field without a default is required; missing key triggers 'missing'.",
  "root_cause_type": "generic",
  "root_cause_zh": "输入字典中缺少必填字段 'email'。在 Pydantic v2 中，没有默认值的字段是必填的；键缺失会触发 missing 错误。",
  "versions": [
    {
      "version": "2.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "Type checker complains and downstream code gets None where str is expected, causing AttributeError later.",
      "fail_rate": 0.55,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Empty string bypasses required validation and pollutes DB with blank emails.",
      "fail_rate": 0.5,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Silently swallows real data problems; later inserts fail with NOT NULL constraint.",
      "fail_rate": 0.4,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.92,
      "how": "from typing import Optional\nfrom pydantic import BaseModel\nclass UserCreate(BaseModel):\n    email: Optional[str] = None",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.8,
      "how": "from pydantic import BaseModel, Field\nclass UserCreate(BaseModel):\n    email: str = Field(default_factory=lambda: 'unknown@example.com')",
      "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": 0.87,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-05-02",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}