{
  "id": "python/unittest-testcase-assertraises-no-context",
  "signature": "TypeError: assertRaises() missing 1 required positional argument: 'callable'",
  "signature_zh": "TypeError: assertRaises() 缺少 1 个必需的位置参数: 'callable'",
  "regex": "TypeError:\\ assertRaises\\(\\)\\ missing\\ 1\\ required\\ positional\\ argument:\\ 'callable'",
  "domain": "python",
  "category": "type_error",
  "subcategory": null,
  "root_cause": "The test calls `self.assertRaises(SomeError)` without the callable or without using it as a context manager. assertRaises requires either a callable as the second argument or use as `with self.assertRaises(SomeError):`.",
  "root_cause_type": "generic",
  "root_cause_zh": "测试调用 `self.assertRaises(SomeError)` 时未提供可调用对象，也未作为上下文管理器使用。assertRaises 需要第二个参数为可调用对象，或使用 `with self.assertRaises(SomeError):` 语法。",
  "versions": [
    {
      "version": "3.9",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "3.12",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "assertRaises expects an exception class or tuple of classes; an instance raises TypeError about expected exceptions.",
      "fail_rate": 0.85,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Loses the assertRaises semantics and can silently pass if the wrong exception type is raised.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.97,
      "how": "Use the context manager form:\n\nwith self.assertRaises(ValueError):\n    parse_bad_input()",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.95,
      "how": "Or pass the callable as the second argument:\n\nself.assertRaises(ValueError, parse_bad_input)",
      "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": "2024-04-22",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}