acidplyr.mutate_at

acidplyr.mutate_at(df: DataFrame, vars: list[str], fun: Callable, *args: Any, **kwargs: Any) → DataFrame

Apply a function to specific columns of a DataFrame.

Parameters:

• df (pd.DataFrame) – Input DataFrame.

• vars (list of str) – Column names to transform. Other columns pass through unchanged.

• fun (callable) – Function applied to each selected column (as a Series).

• *args – Additional positional arguments passed to fun.

• **kwargs – Additional keyword arguments passed to fun.

Returns:

DataFrame with all original columns; vars columns replaced by fun’s output, in the original column order.

Return type:

pd.DataFrame

Examples

>>> import pandas as pd
>>> df = pd.DataFrame({"a": [1, 2], "b": [3, 4]})
>>> mutate_at(df, ["a"], lambda s: s * 2).to_dict("list")
{'a': [2, 4], 'b': [3, 4]}