inputTbl.close()
outputTbl = dbf.Table('c:\\temp\\output.dbf', 'tid N(17.0), zones C(20)')
for tid in sorted(taxIdZoning):
    record = outputTbl.append()
record.tid = tid
record.zones = ','.join(sorted(taxIdZoning[tid]))
outputTbl.close()
concatenate multi values in one record without duplication