def exportSequencesFromBedFile(infile, outfile, masker=None, mode="intervals"):
'''export sequences for intervals in :term:`bed`-formatted *infile*
to :term:`fasta` formatted *outfile*
'''
track = P.snip(infile, ".bed.gz")
fasta = IndexedFasta.IndexedFasta(
os.path.join(P.get_params()["genome_dir"],
P.get_params()["genome"]))
outs = iotools.open_file(outfile, "w")
ids, seqs = [], []
for bed in Bed.setName(Bed.iterator(iotools.open_file(infile))):
lcontig = fasta.getLength(bed.contig)
if mode == "intervals":
seqs.append(fasta.getSequence(bed.contig, "+", bed.start, bed.end))
ids.append("%s_%s %s:%i..%i" %
(track, bed.name, bed.contig, bed.start, bed.end))
elif mode == "leftright":
l = bed.end - bed.start
start, end = max(0, bed.start - l), bed.end - l
ids.append("%s_%s_l %s:%i..%i" %
(track, bed.name, bed.contig, start, end))
seqs.append(fasta.getSequence(bed.contig, "+", start, end))
start, end = bed.start + l, min(lcontig, bed.end + l)
ids.append("%s_%s_r %s:%i..%i" %
(track, bed.name, bed.contig, start, end))
seqs.append(fasta.getSequence(bed.contig, "+", start, end))
masked = maskSequences(seqs, masker)
outs.write("\n".join([">%s\n%s" % (x, y) for x, y in zip(ids, masked)]))
outs.close()
def main(argv=None):
if argv is None:
argv = sys.argv
parser = E.OptionParser(
version="%prog version: $Id$",
usage=globals()["__doc__"])
parser.add_option("-g", "--genome-file", dest="genome_file", type="string",
help="filename with genomic sequence to retrieve "
"sequences from.")
parser.add_option("-m", "--masker", dest="masker", type="choice",
choices=("dust", "dustmasker", "softmask", "none"),
help="apply masker to mask output sequences "
"[%default].")
parser.add_option("--output-mode", dest="output_mode", type="choice",
choices=("intervals", "leftright", "segments"),
help="what to output. "
"'intervals' generates a single sequence for "
"each bed interval. 'leftright' generates two "
"sequences, one in each direction, for each bed "
"interval. 'segments' can be used to output "
"sequence from bed12 files so that sequence only covers "
"the segements [%default]")
parser.add_option("--min-sequence-length", dest="min_length", type="int",
help="require a minimum sequence length [%default]")
parser.add_option("--max-sequence-length", dest="max_length", type="int",
help="require a maximum sequence length [%default]")
parser.add_option(
"--extend-at", dest="extend_at", type="choice",
choices=("none", "3", "5", "both", "3only", "5only"),
help="extend at 3', 5' or both or no ends. If 3only or 5only "
"are set, only the added sequence is returned [default=%default]")
parser.add_option(
"--extend-by", dest="extend_by", type="int",
help="extend by # bases [default=%default]")
parser.add_option(
"--use-strand", dest="ignore_strand",
action="store_false",
help="use strand information and return reverse complement "
"on intervals located on the negative strand. "
"[default=%default]")
parser.set_defaults(
genome_file=None,
masker=None,
output_mode="intervals",
min_length=0,
max_length=0,
extend_at=None,
extend_by=100,
ignore_strand=True,
)
(options, args) = E.start(parser)
if options.genome_file:
fasta = IndexedFasta.IndexedFasta(options.genome_file)
contigs = fasta.getContigSizes()
fasta.setConverter(IndexedFasta.getConverter("zero-both-open"))
counter = E.Counter()
ids, seqs = [], []
E.info("collecting sequences")
for bed in Bed.setName(Bed.iterator(options.stdin)):
counter.input += 1
lcontig = fasta.getLength(bed.contig)
if options.ignore_strand:
strand = "+"
else:
strand = bed.strand
if options.output_mode == "segments" and bed.columns == 12:
ids.append("%s %s:%i..%i (%s) %s %s" %
(bed.name, bed.contig, bed.start, bed.end, strand,
bed["blockSizes"], bed["blockStarts"]))
seg_seqs = [fasta.getSequence(bed.contig, strand, start, end)
for start, end in bed.toIntervals()]
seqs.append("".join(seg_seqs))
elif (options.output_mode == "intervals" or
options.output_mode == "segments"):
ids.append("%s %s:%i..%i (%s)" %
(bed.name, bed.contig, bed.start, bed.end, strand))
seqs.append(
fasta.getSequence(bed.contig, strand, bed.start, bed.end))
elif options.output_mode == "leftright":
l = bed.end - bed.start
start, end = max(0, bed.start - l), bed.end - l
ids.append("%s_l %s:%i..%i (%s)" %
(bed.name, bed.contig, start, end, strand))
seqs.append(fasta.getSequence(bed.contig, strand, start, end))
start, end = bed.start + l, min(lcontig, bed.end + l)
ids.append("%s_r %s:%i..%i (%s)" %
(bed.name, bed.contig, start, end, strand))
seqs.append(fasta.getSequence(bed.contig, strand, start, end))
E.info("collected %i sequences" % len(seqs))
masked = Masker.maskSequences(seqs, options.masker)
options.stdout.write(
"\n".join([">%s\n%s" % (x, y) for x, y in zip(ids, masked)]) + "\n")
E.info("masked %i sequences" % len(seqs))
counter.output = len(seqs)
E.info("%s" % counter)
E.stop()