def _into_iter_mongodb(coll, columns=None, dshape=None):
    seq = coll.find()
    if not columns and dshape:
        columns = dshape.measure.names
    elif not columns:
        item = next(seq)
        seq = concat([[item], seq])
        columns = sorted(item.keys())
        columns.remove('_id')
    return columns, pluck(columns, seq)
Into helper function
dataset/ETHPy150Open blaze/odo/odo/backends/mongo.py/_into_iter_mongodb