Polars: format float values with Polars's configured precision by default

[jeffijoe]

When showing a Polars data frame, floats are shown with full precision, even when pl.Config.set_float_precision(4) has been configured.

It would be cool to be able to explicitly configure the default display precision on itables.options. 👀

[mwouts]

Hi @jeffijoe , great idea! I will look into that. Ideally I would like to truncate the float representation to the desired precision (to make the data transfer to the HTML a bit lighter), plus provide datatables.net with the information that we want that precison.

Would you happen to know, in the polars codebase, where this formatting is applied?

[jeffijoe]

Not sure if this is what you're looking for, but pl.Config.state() returns the configuration as a dict. Example output:

{'POLARS_ENGINE_AFFINITY': None,
 'POLARS_FMT_MAX_COLS': '-1',
 'POLARS_FMT_MAX_ROWS': '30',
 'POLARS_FMT_NUM_DECIMAL': None,
 'POLARS_FMT_NUM_GROUP_SEPARATOR': None,
 'POLARS_FMT_NUM_LEN': None,
 'POLARS_FMT_STR_LEN': None,
 'POLARS_FMT_TABLE_CELL_ALIGNMENT': None,
 'POLARS_FMT_TABLE_CELL_LIST_LEN': None,
 'POLARS_FMT_TABLE_CELL_NUMERIC_ALIGNMENT': None,
 'POLARS_FMT_TABLE_DATAFRAME_SHAPE_BELOW': None,
 'POLARS_FMT_TABLE_FORMATTING': None,
 'POLARS_FMT_TABLE_HIDE_COLUMN_DATA_TYPES': None,
 'POLARS_FMT_TABLE_HIDE_COLUMN_NAMES': None,
 'POLARS_FMT_TABLE_HIDE_COLUMN_SEPARATOR': None,
 'POLARS_FMT_TABLE_HIDE_DATAFRAME_SHAPE_INFORMATION': None,
 'POLARS_FMT_TABLE_INLINE_COLUMN_DATA_TYPE': None,
 'POLARS_FMT_TABLE_ROUNDED_CORNERS': None,
 'POLARS_MAX_EXPR_DEPTH': None,
 'POLARS_STREAMING_CHUNK_SIZE': None,
 'POLARS_TABLE_WIDTH': None,
 'POLARS_VERBOSE': None,
 'POLARS_WARN_UNSTABLE': None,
 'set_fmt_float': 'mixed',
 'set_float_precision': 4,
 'set_thousands_separator': '',
 'set_decimal_separator': '.',
 'set_trim_decimal_zeros': False}