Selector

class skrub.selectors.Selector

Generic selector type, that returns set columns when applied.

This class is not meant to be instantiated manually, Selector objects are created by calling one of the selector builders such as skrub.selectors.all() or skrub.selectors.make_selector().

Methods

expand(df)	Lists the column names that the selector would retain if applied to the dataframe df.
expand_index(df)	Lists the indices of dataframe df's columns that the selector would retain if applied to df.

expand(df)

Lists the column names that the selector would retain if applied to the dataframe df.

Parameters:

dfdataframe

Returns:

list

The list of df’s columns that the item would select.

Notes

In effect, running df[sel.expand(df)] should give the exact same result as sel.transform(df).

Examples

>>> import pandas as pd
>>> from skrub import selectors as s
>>> some_selector = ~s.glob("*_mm")
>>> df = pd.DataFrame(
...     {
...         "height_mm": [210.0, 297.0],
...         "width_mm": [188.5, 210.0],
...         "kind": ["A5", "A4"],
...         "ID": [5, 4],
...     }
... )
>>> some_selector.expand(df)
['kind', 'ID']

expand_index(df)

Lists the indices of dataframe df’s columns that the selector would retain if applied to df.

Parameters:

dfdataframe

Returns:

list

The list of indices among df’s columns that the item would select.

Notes

In effect, (as with expand), if cols is the list of columns in df, running df[cols[i] for i in sel.expand(df)] should give the exact same result as sel.transform(df).

Examples

>>> import pandas as pd
>>> from skrub import selectors as s
>>> some_selector = ~s.glob("*_mm")
>>> df = pd.DataFrame(
...     {
...         "height_mm": [210.0, 297.0],
...         "width_mm": [188.5, 210.0],
...         "kind": ["A5", "A4"],
...         "ID": [5, 4],
...     }
... )
>>> some_selector.expand_index(df)
[2, 3]