{
  "id": "python/unittest-assertraises-invalid-exception",
  "signature": "TypeError: assertRaises() arg 1 must be an exception type or tuple of exception types",
  "signature_zh": "类型错误：assertRaises() 参数 1 必须是异常类型或异常类型的元组",
  "regex": "TypeError:\\ assertRaises\\(\\)\\ arg\\ 1\\ must\\ be\\ an\\ exception\\ type\\ or\\ tuple\\ of\\ exception\\ types",
  "domain": "python",
  "category": "type_error",
  "subcategory": null,
  "root_cause": "Passing a non-exception object (e.g., a string or function) as the first argument to assertRaises.",
  "root_cause_type": "generic",
  "root_cause_zh": "将非异常对象（如字符串或函数）作为 assertRaises 的第一个参数传递。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "assertRaises expects the exception class, not an instance.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Strings are not valid exception types.",
      "fail_rate": 0.95,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.99,
      "how": "with self.assertRaises(ValueError):\n    function_that_raises()",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.99,
      "how": "with self.assertRaises((ValueError, TypeError)):\n    function_that_raises()",
      "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": "2024-05-12",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}