def regulate_colname(catalog, suffix=None):
    """
    Put suffix to the column names of the table.

    Parameters
    ----------

    catalog : astropy.table
        The input astropy table.
    suffix : string
        The string for suffix.
    """
    for col in catalog.colnames:
        col_new = col.strip().lower() + '_' + suffix if suffix else col.strip().lower()
        catalog.rename_column(col, col_new)

    return catalog