# TypeError: assertRaises() missing 1 required positional argument: 'exc'

- **ID:** `python/unittest-assertraises-context-error`
- **Domain:** python
- **Category:** type_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

使用 assertRaises 作为上下文管理器时，未正确传入异常类型

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.12 | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   with self.assertRaises(ValueError): func()
   ```
2. **** (85% success)
   ```
   with self.assertRaisesRegex(ValueError, 'msg'): func()
   ```

## Dead Ends

- **** — 如果调用方式错误，仍然会失败 (30% fail)
- **** — 失去 unittest 的断言功能，测试报告不准确 (50% fail)