“We do this static type checking, and we disallow some of the dynamic features of Python, like changing types at runtime dynamically.”
Codon claims 10 to 100x over regular Python and parity with C++. It gets there by banning the dynamic typing that makes Python Python, and some libraries aren’t implemented yet. The lead author already founded a startup, Exaloop, to sell it. A fast Python that can’t run your Python is a new language with a familiar syntax.