Print list of namedtuples into a table using prtfmt.

def prt_nts(data_nts, prtfmt=None, prt=sys.stdout, nt_fields=None, **kws):
    """Print list of namedtuples into a table using prtfmt."""
    prt_txt(prt, data_nts, prtfmt, nt_fields, **kws)