This issue of PyCoder's Weekly covers a range of topics for Python developers. It features a discussion on profiling and making Python applications fast by default, aligning with Den Odell's new book, "Fast by Default." Another key article addresses migration strategies from pandas to Polars, including LLM-assisted full pipeline migration. There's also an announcement about PR-AF, an open-source code reviewer, performing exceptionally well on Code-Review-Bench.Several articles delve into practical Python usage, such as when to use NotImplemented in dunder methods and building a plugin architecture with Pydantic and FastAPI. An important update from PyPI.org specifies that metadata requests are no longer counted as package downloads, improving download statistics accuracy. Tutorials offer guidance on building face recognition tools and fixing common "NoneType" object errors.Other educational content includes a primer on Python decorators and insights into testing async Python effectively. Developers can also learn about storing Django static and media files on Cloudflare R2. Thought-provoking pieces like "Analysis Paralysis Sucks" and "Why OOP Exists" offer broader development perspectives.A preview of Python 3.15 highlights the default UTF-8 encoding change, with a corresponding quiz. The issue also includes projects like Shedskin, a Python-to-C++ transpiler, and Pandas-silent-bugs, showcasing numerous examples of errors in pandas. Upcoming events for the Python community in September 2026 are also listed, including various meetups and PyCon Cameroon.