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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_loci_fasta(loci, out_fa, ref):
 """get fasta from precursor"""

    if not find_cmd("bedtools"):
        raise ValueError("Not bedtools installed")
    with make_temp_directory() as temp:
        bed_file = os.path.join(temp, "file.bed")
        for nc, loci in loci.iteritems():
            for l in loci:
                with open(bed_file, 'w') as bed_handle:
                    logger.debug("get_fasta: loci %s" % l)
                    nc, c, s, e, st = l
                    print("{0}\t{1}\t{2}\t{3}\t{3}\t{4}".format(c, s, e, nc, st), file=bed_handle)
                get_fasta(bed_file, ref, out_fa)
    return out_fa