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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def iter_fasta_qual(fastafile, qualfile, defaultqual=OKQUAL, modify=False):
 """ used by trim, emits one SeqRecord with quality values in it """

    from Bio.SeqIO.QualityIO import PairedFastaQualIterator
    if not qualfile:
        qualfile = make_qual(fastafile, score=defaultqual)

    rec_iter = PairedFastaQualIterator(open(fastafile), open(qualfile))
    for rec in rec_iter:
        yield rec if not modify else modify_qual(rec)