{
  "id": "python/pandas-concat-empty-frames",
  "signature": "ValueError: No objects to concatenate",
  "signature_zh": "ValueError: 没有可连接的对象",
  "regex": "ValueError:\\ No\\ objects\\ to\\ concatenate",
  "domain": "python",
  "category": "runtime_error",
  "subcategory": null,
  "root_cause": "pd.concat() received an empty list, typically because a filter or list comprehension produced no DataFrames.",
  "root_cause_type": "generic",
  "root_cause_zh": "pd.concat() 收到空列表，通常因为过滤或列表推导未产生任何 DataFrame。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "ignore_index doesn't help with empty list",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Downstream code then fails on None",
      "fail_rate": 0.75,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.95,
      "how": "if frames: result = pd.concat(frames, ignore_index=True) else: result = pd.DataFrame()",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.9,
      "how": "result = pd.concat(frames or [pd.DataFrame()], ignore_index=True)",
      "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": 0.88,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-03-30",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}