Has anyone used Polars and Seaborn or Matplotlib together?

Question

Has anyone used a Polars dataframe with Seaborn to graph something? I've been working through a notebook on Kaggle that used Pandas, and I wanted to refactor it to Polars.

The dataframe I'm working with looks like this:

PassengerID (i64)	Survived (i64)	Pclass (i64)	Name (str)	...	Ticket (str)	Fare (f64)	Cabin (str)	Embarked (str)	Age (f64)
1	0	3	your name here	...	A/5 21171	7.25	null	S	24
...	...	...	...	...	...	...	...	...	...

Kaggle has me making a histogram with the following code:

g = sns.FacetGrid(train_df, col='Survived')
g.map(plt.hist, 'Age', bins=20)

When I run these two lines I get the following error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/seaborn/axisgrid.py", line 678, in map
    for (row_i, col_j, hue_k), data_ijk in self.facet_data():
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/seaborn/axisgrid.py", line 632, in facet_data
    data_ijk = data[row & col & hue & self._not_na]
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/polars/internals/series/series.py", line 906, in __array_ufunc__
    args.append(arg.view(ignore_nulls=True))
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/polars/internals/series/series.py", line 2680, in view
    ptr_type = dtype_to_ctype(self.dtype)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/polars/datatypes.py", line 550, in dtype_to_ctype
    raise NotImplementedError(
NotImplementedError: Conversion of polars data type <class 'polars.datatypes.Boolean'> to C-type not implemented.

I don't have any boolean datatypes in my dataframe, so I'm not sure what to do about this error. Any ideas?

Link

It is not recommended to directly use sns.FacetGrid. The correct methods are ax = sns.histplot(data=train_df.to_pandas(), x='Age', col='Survived', bins=20) or g = sns.displot(data=train_df.to_pandas(), x='Age', col='Survived', bins=20) – Aleman

Answer 1

seaborn doesn't accept a polars dataframe as an input. You just have to use to_pandas()

so change g = sns.FacetGrid(train_df, col='Survived') to

g = sns.FacetGrid(train_df.to_pandas(), col='Survived')

Peridotite

Answer 2

Now, Seaborn supports DataFrame objects from libraries other than pandas (e.g. polars) using Dataframe Exchange Protocol.

Check it out here.

Situation