DashScopeAPIResponse.__getattr__ raises KeyError instead of AttributeError

[marklysze]

Bug

DashScopeAPIResponse.__getattr__ (line 62 of dashscope/api_entities/dashscope_response.py) raises KeyError when an attribute is missing, but Python's attribute-access protocol expects AttributeError.

# Current code
def __getattr__(self, attr):
    return self[attr]  # raises KeyError if attr is missing

Impact

This breaks two common Python patterns:

# Both of these fail because KeyError is raised instead of AttributeError
getattr(response.output, "reasoning_content", None)  # KeyError instead of returning None
hasattr(response.output, "reasoning_content")          # KeyError instead of returning False

getattr(obj, name, default) and hasattr(obj, name) both rely on AttributeError to trigger the default/fallback path. A KeyError propagates as an unhandled exception.

Suggested Fix

def __getattr__(self, attr):
    try:
        return self[attr]
    except KeyError:
        raise AttributeError(attr) from None

References

• Python data model — __getattr__: "Called when the default attribute access fails with AttributeError"
• Built-in getattr: "If the named attribute does not exist, default is returned if provided, otherwise AttributeError is raised."

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中文说明

问题描述

DashScopeAPIResponse.__getattr__（位于 dashscope/api_entities/dashscope_response.py 第 62 行）在属性不存在时抛出 KeyError，但 Python 的属性访问协议要求抛出 AttributeError。

# 当前代码
def __getattr__(self, attr):
    return self[attr]  # 属性不存在时抛出 KeyError

影响

这会导致两种常见的 Python 用法失效：

# 以下两种写法都会失败，因为抛出的是 KeyError 而非 AttributeError
getattr(response.output, "reasoning_content", None)  # 抛出 KeyError，而非返回 None
hasattr(response.output, "reasoning_content")          # 抛出 KeyError，而非返回 False

getattr(obj, name, default) 和 hasattr(obj, name) 都依赖 AttributeError 来触发默认值/回退逻辑。KeyError 会作为未处理的异常向上传播。

建议修复

def __getattr__(self, attr):
    try:
        return self[attr]
    except KeyError:
        raise AttributeError(attr) from None

参考资料

• Python 数据模型 — __getattr__："当默认属性访问因引发 AttributeError 而失败时被调用"
• 内置函数 getattr："如果指定的属性不存在，且提供了 default 值，则返回它，否则触发 AttributeError"