def readable(df):

    """Take a dataframe and remove all columns that end in the suffix '_id'.

    The intended purpose of this function is to display a dataframe on the
    console showing only the readable columns i.e. not the identifiers.

    Parameters
    ----------
    df : DataFrame
        A pandas dataframe.

    Returns
    -------
    out : DataFrame
        A dataframe with the same structure as the input df with any columns
        ending in the suffix '_id' removed.

    """

    readable_cols = list(filter(lambda c: not c.endswith('_id'), df.columns))
    return df[readable_cols]