Turns a dict from a line of protein/peptide quant data into a set of
    tuples that can be stored in db

def get_isob_quant_data(pquant, header, fnid, featmap, featcol, qmap):
    """Turns a dict from a line of protein/peptide quant data into a set of
    tuples that can be stored in db"""
    feat_dbid = featmap[pquant[header[featcol]]]
    for channel_name, (channel_id, psmfield) in qmap[fnid].items():
        if psmfield is None:
            yield (feat_dbid, channel_id, pquant[channel_name])
        else:
            yield (feat_dbid, channel_id, pquant[channel_name],
                   pquant[psmfield])