Work with PolaRs in knime

[MNVADGAMA]

Hi friends,

We can import data in pyarrow or pandas dataframe.

After importing data, how can we process data using polars library.

Thanks for your answer.

[mlauber71]

@MNVADGAMA I see the option to convert a dataset to a polars dataframe from pandas. I was not (yet) able to use a direct transfer from (KNIME) Arrow format to Polars (and back).

kn_example_python_polars_pandas_arrow.knwf (35.2 KB)

working with Polars dataframe in KNIME Python node – mlauber71

[MNVADGAMA]

Thanks @mlauber71 for your response.

I also tried groupby polars dataframe as under (see row no 21):

The ouput of polars and pandas is as under:

However, getting following errors

How can we address such error.

Thanks,
Manish

[steffen_KNIME]

Dear @MNVADGAMA Manish,

unsigned int (uint32) is not supported. Could you change the data type of the count column and tell us whether that works?

I dug into the Polar code base, but where the count method is really executed, is somewhere far in the back and I do not see how one could change the type with some polar method. Only that they always seem to return uint32.

Best regards
Steffen