def get_next_counts(file):
    """
    read next line in file, extract counts from line
    :param file: given file, already opened
    :return: chromosome, position and counts
    """
    new_line = file.readline()
    line = new_line.decode()
    line = line.strip('\n').split('\t')
    if len(line) == 11:
        chrom = line[0]

        pos = int(line[1])
        counts = [int(line[10]), int(line[9]), int(line[8]), int(line[7])]
        return chrom, pos, counts
    else:
        # end of file
        return -1, -1, []