List of supported libraries (and how to add yours!)
Currently, Narwhals supports the following libraries as inputs:
- pandas
- Polars
- cuDF
- Modin
If you want your own library to be recognised too, you're welcome open a PR (with tests)! Alternatively, if you can't do that (for example, if you library is closed-source), see the next section for what else you can do.
Extending Narwhals
We love open source, but we're not "open source absolutists". If you're unable to open source you library, then this is how you can make your library compatible with Narwhals.
Make sure that, in addition to the public Narwhals API, you also define:
DataFrame.__narwhals_dataframe__
: return an object which implements public methods fromNarwhals.DataFrame
DataFrame.__narwhals_namespace__
: return an object which implements public top-level functions fromnarwhals
(e.g.narwhals.col
,narwhals.concat
, ...)LazyFrame.__narwhals_lazyframe__
: return an object which implements public methods fromNarwhals.LazyFrame
LazyFrame.__narwhals_namespace__
: return an object which implements public top-level functions fromnarwhals
(e.g.narwhals.col
,narwhals.concat
, ...)Series.__narwhals_series__
: return an object which implements public methods fromNarwhals.Series
Series.__narwhals_namespace__
: return an object which implements public top-level functions fromnarwhals
(e.g.narwhals.col
,narwhals.concat
, ...)
If your library doesn't distinguish between lazy and eager, then it's OK for your dataframe
object to implement both __narwhals_dataframe__
and __narwhals_lazyframe__
. In fact,
that's currently what narwhals._pandas_like.dataframe.PandasDataFrame
does. So, if you're stuck,
take a look at the source code to see how it's done!
Note that the "extension" mechanism is still experimental. If anything is not clear, or doesn't work, please do raise an issue or contact us on Discord (see the link on the README).