def METHOD_NAME( file_path ):
    molecules = dict()
    snp_count = 0
    fh = None
    if file_path.endswith(".gz"):
        fh = gzip.GzipFile(file_path, "r")
    else:
        fh = open(file_path)
    total_seq_length = 0
    sample_id = None
    for line in fh:
        line = line.rstrip()
        cols = line.split("\t")
        if line.startswith("#"):
            continue
        cols = line.split("\t")
        mol = cols[0]
        pos = cols[1]
        alt = cols[4]
        if len(cols) < 7 or alt == '.' or cols[6] != 'PASS':
            continue
        ## store this SNP
        if mol not in molecules:
            molecules[mol] = dict()
        molecules[mol][pos] = { 'alt': alt, 'inf': False }
        snp_count += 1
    print("INFO: parsed {0} SNPs in file: {1}".format(snp_count, file_path) )
    return molecules