[ASK] The docstring explanation for LibffmConverter

[Tony-Feng]

Description

Hello Dev Team,

In the docstring of LibffmConverter:
https://github.com/microsoft/recommenders/blob/fe215e9babf8f7caba025a83059445362cff0006/recommenders/datasets/pandas_df_utils.py#L112

I'm wondering if this line would be the following one instead:

i.e. `<field_index>:<field_feature_index>:1` or `<field_index>:<field_feature_index>:<field_feature_value>`

Since according to:
https://github.com/microsoft/recommenders/blob/fe215e9babf8f7caba025a83059445362cff0006/recommenders/datasets/pandas_df_utils.py#L225
The returned value is in form of <field_index>:<field_feature_index>:<field_feature_value> instead of <field_index>:<field_index>:<field_feature_value>.

A PR #1669 has been made to fix this typo if applicable.

Thank you very much.

[Tony-Feng]

Hello @miguelgfierro, thanks for reviewing the PR. I'm also wondering if there would be a specific reason for selecting 1 in <field_index>:<field_feature_index>:1 for strings? Thanks again!

[miguelgfierro]

That's just an example, you can add the value you want