示例

six lazy moved descriptors cache resolved targets directly onto instance dictionaries while deleting themselves from parent class dictionaries, causing class-level lookups to fail and leaving sys.meta_path importers decoupled from remove_move and add_move

sha256:b632b8e946a5c728dc7d1654280ec14c45ffffd3c37cf0d43ddaa4ece84a11da

案例

目标

six lazy moved descriptors cache resolved targets directly onto instance dictionaries while deleting themselves from parent class dictionaries, causing class-level lookups to fail and leaving sys.meta_path importers decoupled from remove_move and add_move HOW

包

six 1.17.0

环境

python

创建时间

2026-08-17T07:05:16Z

常见的想当然

Accessing moved attributes on six.moves or its classes returns the descriptor or resolved object identically without mutating class state, and six.remove_move cleans up import hooks alongside attribute access

这是本样本作者记下的、开发者或模型在此处通常会有的预期。下面的契约才是真正运行过的东西。

契约

• Accessing an attribute on six.moves or its lazy namespaces resolves the target, caches it in the instance dictionary, and deletes the lazy descriptor from the class dictionary, making class-level attribute access fail with AttributeError
• Accessing unresolved lazy descriptors directly on six._MovedItems raises AttributeError because _LazyDescr attempts setattr on None instead of returning self
• six.remove_move purges moves from _MovedItems and six.moves instance dictionaries while leaving six._importer.known_modules intact, allowing subsequent import statements to re-resolve the removed module
• six.add_move registers descriptors on _MovedItems for attribute lookup but does not update six._importer.known_modules, causing direct import statements for added moves to raise ModuleNotFoundError
• Direct attribute lookup on MovedModule instances resolves the underlying module and caches the attribute on the descriptor instance via __getattr__
• six.reraise clears its local value and traceback references in a finally block to prevent circular reference cycles between execution frames and traceback objects

文件

• NOTES.md
• csx.json
• requirements.txt
• test/__init__.py
• test/contract.py

下载源代码构件 (tar.gz)

原始种子者

csx-seed

验证回执

• python 3.12 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17 · ed25519:d91480838ac982c9