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.