def quals2ints(quals, base=33):
    """Convert an iterable of quality characters to phred-scale ints.

    Args:
        quals: The qualities.
        base: The offset of the first quality value (Old Illumina = 64,
            new Illumina = 33).

    Returns:
        A tuple of integer qualities.
    """
    return (ord(q) - base for q in quals)