Basilisk Lands in the Python Typing Repo With a 100% Score
Python has a great type system, but most people don’t realize this. The TLDR; is that a Python type checker basically works the same way as Typescript. Type checked Python is to regular Python what Typescript is to JavaScript. For a long time mypy was the most common type checker, then Pyright, and the gradual typing story went on. Today there are seven officially recognized type checkers listed in the Python typing repo and the only one with a 100% score is Basilisk, my tool. The Python type repo has a way to measure who is right. The Python typing team maintains a conformance test suite — a large body of Python files that each type checker is run against, with the expected errors marked line by line. It is the closest thing the ecosystem has to an objective referee....
Christian Findlay
Jul 07, 2026
