Python

Writes, debugs, and reviews Python code — runtime traps, packaging, typing, async, tests, performance. Use when Python raises or misbehaves: ModuleNotFoundError, circular imports, AttributeError on None, UnboundLocalError, UnicodeDecodeError, mutable default arguments, `is` vs `==`, float rounding, naive vs aware datetimes, or a wrong answer with no exception; when pip, uv, poetry, venv, pyproject or a lockfile fight over dependencies, or a package installs but will not import; when threads, asyncio, multiprocessing or the GIL hang, deadlock, or leak memory; when pytest passes but should not, mocks patch the wrong module, or async tests never run; when mypy or pyright errors need clearing; when a script is slow, eats RAM, or gets OOM-killed; when subprocess calls hang or logs never appear; or when upgrading Python breaks the build. Not for library-specific problems — pandas, numpy, django, fastapi and flask have their own skills.

This skill is reasonable to install if you want Python guidance. It can cause the agent to suggest commands, dependency installs, file edits, and preference storage, so review generated commands and any remembered preferences before applying them.