Fill function for create_featuredata_map

def add_psms_to_proteindata(proteindata, p_acc, pool, psmdata):
    """Fill function for create_featuredata_map"""
    seq, psm_id = psmdata[2], psmdata[3]
    try:
        proteindata[p_acc]['pools'][pool]['psms'].add(psm_id)
    except KeyError:
        emptyinfo = {'psms': set(), 'peptides': set(), 'unipeps': 0}
        try:
            proteindata[p_acc]['pools'][pool] = emptyinfo
        except KeyError:
            proteindata[p_acc].update({'pools': {pool: emptyinfo}})
        proteindata[p_acc]['pools'][pool]['psms'].add(psm_id)
    proteindata[p_acc]['pools'][pool]['peptides'].add(seq)