def return_assignment(input_df, column_name, selected):
    """Return entries where one column matches with selected in dataframe."""
    if isinstance(selected, list):
        # a list of selected assignments
        return input_df[input_df[column_name].isin(selected)].dropna(
            axis="columns", how="all"
        )
    elif isinstance(selected, str):
        # one selected assignment
        return input_df[input_df[column_name] == selected].dropna(
            axis="columns", how="all"
        )
    else:
        raise TypeError(f"{selected} is not list or str type")