Narwhals

Extremely lightweight and extensible compatibility layer between dataframe libraries!

Full API support: cuDF, Modin, pandas, Polars, PyArrow
Lazy-only support: Dask
Interchange-level support: Ibis, DuckDB, Vaex, anything else which implements the DataFrame Interchange Protocol

Seamlessly support all, without depending on any!

✅ Just use a subset of the Polars API, no need to learn anything new
✅ Zero dependencies, Narwhals only uses what the user passes in so your library can stay lightweight
✅ Separate lazy and eager APIs, use expressions
✅ Support pandas' complicated type system and index, without either getting in the way
✅ 100% branch coverage, tested against pandas and Polars nightly builds
✅ Negligible overhead, see overhead
✅ Let your IDE help you thanks to full static typing, see typing
✅ Perfect backwards compatibility policy, see stable api for how to opt-in

Who's this for?

Anyone wishing to write a library/application/service which consumes dataframes, and wishing to make it completely dataframe-agnostic.

Let's get started!

See roadmap discussion on GitHub for an up-to-date plan of future work.