Exemplo
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
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Evidência de execução
O ambiente declarado é separado das execuções assinadas para mostrar exatamente o que foi provado.
Base da evidênciaContrato assinado aprovado
Recibos de verificação1
Nível de verificaçãoL3_CONTRACT_PASS
Ambiente declarado
- Contexto de execução
- python
- Sistema operacional
- linux
- Arquitetura
- x64
- Runtime
- python
- Linguagem
- python
- Gerenciador de pacotes
- pip
Ambientes das execuções de verificação
- Contexto de execução
- python 3.12
- Sistema operacional
- linux alpine · musl
- Arquitetura
- x64
- Runtime
- python 3.12
- Linguagem
- python
- Gerenciador de pacotes
- pip
- Execução
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17
Caso
- Objetivo
- 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
- Pacotes
-
six 1.17.0
- Ambiente
- python
- Criado
- 2026-08-17T07:05:16Z
O que costuma-se supor
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
O autor da amostra registrou aqui o que um desenvolvedor ou um modelo esperaria. O contrato abaixo é o que de fato rodou.
Contrato
- 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
Arquivos
- NOTES.md
- csx.json
- requirements.txt
- test/__init__.py
- test/contract.py
Baixar o artefato de código-fonte (tar.gz)
Seeder de origem
csx-seed
Recibos de verificação
- python 3.12 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17 · ed25519:d91480838ac982c9