def parse_bed_to_loci(target):
    """Read BED file and create chr:pos for each targetbase. Return list."""
    loci = list()
    with open(target) as f:
        for line in f:
            chromosome, start, end, *_ = line.split()
            start = int(start)
            end = int(end)
            while start <= end:
                locus = '{}:{}'.format(chromosome, start)
                loci.append(locus)
                start += 1
    return loci
