These days we have Starlark, which is the core part of Python, modified to be completely hermetic & deterministic (by removing some things and changing others), and modified to support parallel execution. It is very nice to work with, since you can use a lot of Python tooling and Python experience, but you don’t have to carry around a complete Python implementation.
It was originally part of Bazel but it is used in other tools, and there are multiple implementations.
It was originally part of Bazel but it is used in other tools, and there are multiple implementations.