num-derive | Procedural macros to derive numeric traits in Rust | Genomics library

There is currently no derivation for this type of enum. The FromPyObject derivation is designed to handle polymorphic input from the Python side, not to discriminate between unit types.

However, there has been a stale PR for adding general enum support on PyO3 since last year's summer. If this gets some movement, you might be able to deal with Python Enums in the future.

Until then, you'll need to implement FromPyObject by hand and decide what inputs map to which variant.

If you want to pass a string from Python and get the matching enum variant in Rust from it, you could also make your interface take a String in Rust, add a impl TryFrom<&str> for Direction and try the conversion in your interfacing function.