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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 _get_fastq_in_region(region, align_bam, out_base):
 """Retrieve fastq files in region as single end. Paired end is more complicated since pairs can map off the region, so focus on local only assembly since we've previously used paired information for mapping. """

    out_file = "{0}.fastq".format(out_base)
    if not file_exists(out_file):
        with pysam.Samfile(align_bam, "rb") as in_pysam:
            with file_transaction(out_file) as tx_out_file:
                with open(tx_out_file, "w") as out_handle:
                    contig, start, end = region
                    for read in in_pysam.fetch(contig, int(start), int(end)):
                        seq = Seq.Seq(read.seq)
                        qual = list(read.qual)
                        if read.is_reverse:
                            seq = seq.reverse_complement()
                            qual.reverse()
                        out_handle.write("@{name}\n{seq}\n+\n{qual}\n".format(
                                name=read.qname, seq=str(seq), qual="".join(qual)))
    return out_file