Python · 禁裸 except

规则

不允许：

# ❌ 1. 裸 except — 连 KeyboardInterrupt 都吞
try: ...
except: pass

# ❌ 2. except Exception 不记日志
try: ...
except Exception:
    pass

# ❌ 3. except Exception 不重抛
try: ...
except Exception as e:
    logger.error(f"failed: {e}")   # 静默掉了，调用方以为成功
    return None

正确做法

必须捕获并恢复

try:
    return await primary_provider.call(req)
except (TimeoutError, ConnectionError) as e:
    logger.warning(f"主 provider 失败，切换备用: {e}")
    return await backup_provider.call(req)

捕获具体异常类型，不要 except Exception。

必须抛出但要清理

deducted = False
try:
    deducted = await deduct_credits(uid, 1)
    return await call_llm(req)
except ApiException:
    raise
except Exception as e:
    logger.exception(f"LLM 调用失败 - uid={uid}: {e}")
    raise ApiException(msg="生成失败，请重试")
finally:
    if deducted and not success:
        await restore_credits(uid, 1)

except 选择决策表

反例

# ❌ 把所有错都当成 None
try:
    user = await User.filter(id=uid).first()
except:
    user = None

# ✅ 仅 Tortoise 的 DoesNotExist 才返回 None
user = await User.filter(id=uid).first()  # 已经返回 None，无需 try

自检

• [ ] 没有 except: 裸接？
• [ ] 没有 except Exception: pass？
• [ ] except Exception 都带 exc_info=True 并 raise？
• [ ] 业务异常用 except ApiException: raise 透传？

相关

• 父：./index.md
• 兄弟：api-exception.md · logger-exc-info.md