Narwhals

Extremely lightweight compatibility layer between Polars, pandas, and more.

Seamlessly support both, without depending on either!

• ✅ 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!