No, there is no pure-Python Starlark. So far there are only Python bindings for the Go and the Rust implementation: https://github.com/laurentlb/awesome-starlark#getting-starte.... I thought about porting the Go implementation to Python. Doing it as a subgoal for porting recur seemed a little like scope creep. (Tokei says there are 16792 SLOC in the latest d4d7611 commit of starlark-go and 899 in recur 67b38c1.)