def pp_file_to_dataframe(pp_filename):

    """ read a pilot point file to a pandas Dataframe

    Parameters
    ----------
    pp_filename : str
        pilot point file

    Returns
    -------
    df : pandas.DataFrame
        a dataframe with pp_utils.PP_NAMES for columns

    """

    df = pd.read_csv(pp_filename, delim_whitespace=True,
                     header=None, names=PP_NAMES,usecols=[0,1,2,3,4])
    df.loc[:,"name"] = df.name.apply(str).apply(str.lower)
    return df
read a pilot point file to a pandas Dataframe

    Parameters
    ----------
    pp_filename : str
        pilot point file

    Returns
    -------
    df : pandas.DataFrame
        a dataframe with pp_utils.PP_NAMES for columns