{
  "id": "python/pydantic-validation-error-datetime-parsing",
  "signature": "pydantic_core._pydantic_core.ValidationError: 1 validation error for Event\ntimestamp\n  Input should be a valid datetime, invalid date separator, expected 'T' or ' ' [type=datetime_parsing, input_value='2024-01-15_10:30:00', input_type=str]",
  "signature_zh": "pydantic_core._pydantic_core.ValidationError: Event 模型验证错误：timestamp 不是有效的 datetime，日期分隔符错误，应为 'T' 或空格",
  "regex": "pydantic_core\\._pydantic_core\\.ValidationError:\\ 1\\ validation\\ error\\ for\\ Event\\\ntimestamp\\\n\\ \\ Input\\ should\\ be\\ a\\ valid\\ datetime,\\ invalid\\ date\\ separator,\\ expected\\ 'T'\\ or\\ '\\ '\\ \\[type=datetime_parsing,\\ input_value='2024\\-01\\-15_10:30:00',\\ input_type=str\\]",
  "domain": "python",
  "category": "data_error",
  "subcategory": null,
  "root_cause": "The datetime string uses an invalid separator (e.g. underscore). Pydantic v2 uses RFC 3339 / ISO 8601 parsing and requires 'T' or a space between date and time.",
  "root_cause_type": "generic",
  "root_cause_zh": "datetime 字符串使用了无效的分隔符（如下划线）。Pydantic v2 使用 RFC 3339 / ISO 8601 解析，要求日期与时间之间用 'T' 或空格分隔。",
  "versions": [
    {
      "version": "2.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "strptime works but bypasses Pydantic validation, so type errors surface later as AttributeError.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Loses timezone-aware comparison and arithmetic capabilities.",
      "fail_rate": 0.75,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.95,
      "how": "value = '2024-01-15_10:30:00'.replace('_', 'T', 1)",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.92,
      "how": "from datetime import datetime\nfrom pydantic import BaseModel, field_validator\n\nclass Event(BaseModel):\n    timestamp: datetime\n\n    @field_validator('timestamp', mode='before')\n    @classmethod\n    def parse_dt(cls, v):\n        if isinstance(v, str):\n            return datetime.strptime(v, '%Y-%m-%d_%H:%M:%S')\n        return v",
      "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": 0.86,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-09-11",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}