python / python/cpython

AttributeError on `with super()`

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interpreter-core type-feature
主要語言
Python
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1 天 9 小時
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描述

Bug report

Bug description:

Writing with super() raises an AttributeError. I ran into this implementing context managers inspired by contextlib.contextmnager but which had extra functionality. I can see no reason why with super() should be disallowed, and in fact, super().__enter__() and super().__exit__() work just fine.

Attempting to use an ExitStack as a work around was unsuccessful.

import sys
from contextlib import ExitStack

class Base:
    def __enter__(self):
        print("Entering base context manager")

    def __exit__(self, type, value, traceback):
        print("Exiting base context manager")

def __derived_enter__(self):
    self.context = self.contextlib_style_context()
    next(self.context)
    return self.context

def __derived_exit__(self, type, value, traceback):
    try:
        next(self.context)
    except StopIteration:
        pass

class DerivedUsingEnterExit(Base):
    def contextlib_style_context(self):
        print("Entering contextlib style context manager")
        super().__enter__()
        try:
            yield
        finally:
            super().__exit__(*sys.exc_info())

        print("Exiting contextlib style context manager")

    __enter__ = __derived_enter__
    __exit__ = __derived_exit__

class DerivedUsingWith(Base):
    def contextlib_style_context(self):
        print("Entering contextlib style context manager")
        with super():
            yield

        print("Exiting contextlib style context manager")

    __enter__ = __derived_enter__
    __exit__ = __derived_exit__

class DerivedUsingExitStack(Base):
    def contextlib_style_context(self):
        print("Entering contextlib style context manager")

        with ExitStack() as stack:
            stack.enter_context(super())
            yield

        print("Exiting contextlib style context manager")

    __enter__ = __derived_enter__
    __exit__ = __derived_exit__

# Runs successfully
with DerivedUsingEnterExit() as d:
    pass

# Raises AttributeError
with DerivedUsingWith() as d:
    pass

# Raises AttributeError
with DerivedUsingExitStack() as d:
    pass
CPython versions tested on:

3.13, 3.12

Operating systems tested on:

Windows

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  4. 送出 Pull Request,並在描述裡引用這個 Issue 編號。

研究方向

先在 CPython 3.13 或 3.12 上重現所提供的 DerivedUsingWith 和 DerivedUsingExitStack 範例,然後追蹤涉及的 super() 和內容管理器進入點。將它們與正常運作的 super().enter() 和 super().exit() 情況進行比較;完成表示預期行為已確定,且回報的 AttributeError 已由回歸測試涵蓋。

由索引模型根據 Issue 內容生成。

評估

技術堆疊
python
領域
compilers
Issue 類型
缺陷
難度
4/5
預估耗時
3-5 天
活躍度
停滯
描述清晰度
基本清楚
新手友好度
35/100

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