# AssertionError: assert {'a': 1, 'b': 2} == {'a': 1, 'b': 3}

- **ID:** `python/pytest-assert-dict-difference`
- **Domain:** python
- **Category:** data_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

测试中比较两个字典，但键'b'的值不一致，导致断言失败。

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.9 | active | — | — |

## Workarounds

1. **** (90% success)
   ```
   expected = {'a': 1, 'b': 2}
assert actual == expected
   ```
2. **** (85% success)
   ```
   assert actual == pytest.approx(expected)
   ```

## Dead Ends

- **** — 忽略了其他键，可能掩盖错误。 (70% fail)
- **** — 字典顺序可能不同，导致假失败。 (80% fail)