def get_num_reads(self):
"""
Return number of reads in FASTA/FASTQ file.
For single-end samples, returns a single number.
For paired-end samples, return a comma-separated
pair of numbers: 'num_left_mate,num_right_mate'
"""
self.logger.info("Getting number of reads.")
if self.sample.paired:
self.logger.info("Getting number of paired-end reads.")
# Paired-end
mate_reads = []
for mate_rawdata in self.sample.rawdata:
num_reads = 0
fastx_entries = fastx_utils.get_fastx_entries(mate_rawdata.reads_filename)
for entry in fastx_entries:
num_reads += 1
mate_reads.append(num_reads)
pair_num_reads = ",".join(map(str, mate_reads))
return pair_num_reads
else:
self.logger.info("Getting number of single-end reads.")
num_reads = 0
# Single-end
fastx_entries = fastx_utils.get_fastx_entries(self.sample.rawdata.reads_filename)
for entry in fastx_entries:
num_reads += 1
return num_reads
def get_num_reads(self):
"""
Return number of reads in FASTA/FASTQ file.
For single-end samples, returns a single number.
For paired-end samples, return a comma-separated
pair of numbers: 'num_left_mate,num_right_mate'
"""
self.logger.info("Getting number of reads.")
if self.sample.paired:
self.logger.info("Getting number of paired-end reads.")
# Paired-end
mate_reads = []
for mate_rawdata in self.sample.rawdata:
num_reads = 0
fastx_entries = \
fastx_utils.get_fastx_entries(mate_rawdata.reads_filename)
for entry in fastx_entries:
num_reads += 1
mate_reads.append(num_reads)
pair_num_reads = ",".join(map(str, mate_reads))
return pair_num_reads
else:
self.logger.info("Getting number of single-end reads.")
num_reads = 0
# Single-end
fastx_entries = \
fastx_utils.get_fastx_entries(self.sample.rawdata.reads_filename)
for entry in fastx_entries:
num_reads += 1
return num_reads
def output_bed_coords_from_fasta(fasta_fname, bed_fname):
"""
Output event coordinates from a FASTA file into a BED
format.
Assumes FASTA entry is of the form:
>part_id:coords:entry_type
"""
print "Converting FASTA %s to BED %s" %(fasta_fname,
bed_fname)
total_len = 0
with open(bed_fname, "w") as bed_out:
for fasta_entry in fastx_utils.get_fastx_entries(fasta_fname):
fasta_name, fasta_seq = fasta_entry
# Assume FASTA entry coordinates are in GFF format.
# Convert them to BED
if ";" not in fasta_name:
raise Exception, "Malformed FASTA entry name: %s" %(fasta_name)
gff_coords = fasta_name.split(";")[1]
chrom, start, end, strand = parse_gff_coords(gff_coords)
# Convert start to BED by subtracting one
start = start - 1
bed_entry = \
pybedtools.create_interval_from_list(map(str, [chrom, start, end,
gff_coords, "1",
strand]))
bed_out.write("%s" %(str(bed_entry)))
# Accumulate total length of FASTA seqs
total_len += len(fasta_seq)
return total_len
def load_fastx_into_ktable(fastx_fname, kmer_len):
t1 = time.time()
ktable = khmer.new_ktable(kmer_len)
# Load up the FASTA into ktable
for fastx_entry in fastx_utils.get_fastx_entries(fastx_fname):
fastx_name, fastx_seq = fastx_entry
# Skip very short sequences
if len(fastx_seq) < kmer_len:
continue
ktable.consume(fastx_seq)
t2 = time.time()
print "Loading up of seqs into ktable took %.2f seconds." %(t2 - t1)
return ktable
def load_fastx_into_ktable(fastx_fname, kmer_len):
t1 = time.time()
ktable = khmer.new_ktable(kmer_len)
# Load up the FASTA into ktable
for fastx_entry in fastx_utils.get_fastx_entries(fastx_fname):
fastx_name, fastx_seq = fastx_entry
# Skip very short sequences
if len(fastx_seq) < kmer_len:
continue
ktable.consume(fastx_seq)
t2 = time.time()
print "Loading up of seqs into ktable took %.2f seconds." % (t2 - t1)
return ktable
def jf_counts_to_dict(jf_counts_fname):
"""
Load jellyfish counts file (a FASTA file)
into a dictionary mapping kmers to counts.
"""
kmer_counts = defaultdict(int)
if not os.path.isfile(jf_counts_fname):
print "Error: Cannot find jf counts file %s" % (jf_counts_fname)
sys.exit(1)
for fastx_entry in fastx_utils.get_fastx_entries(jf_counts_fname,
fasta=True):
kmer_count, kmer = fastx_entry
# Remove prefix '>' from FASTA entry
kmer_count = int(kmer_count[1:])
kmer_counts[kmer] = kmer_count
return kmer_counts
def output_dinuc_shuffled_fasta(fasta_fname, shuffled_fasta_fname,
num_shuffles=1):
"""
Given a FASTA file, output a dinucleotide shuffled version of it.
"""
fasta_out = fastx_utils.write_open_fastx(shuffled_fasta_fname)
for fastx_entry in fastx_utils.get_fastx_entries(fasta_fname):
fastx_name, fastx_seq = fastx_entry
shuffled_recs = []
for shuffle_num in range(num_shuffles):
shuffled_seq = \
get_dinuc_shuffles(fastx_seq)[0]
shuffled_rec = (fastx_name, shuffled_seq)
shuffled_recs.append(shuffled_rec)
fasta_utils.write_fasta(fasta_out, shuffled_recs)
fasta_out.close()
def jf_counts_to_dict(jf_counts_fname):
"""
Load jellyfish counts file (a FASTA file)
into a dictionary mapping kmers to counts.
"""
kmer_counts = defaultdict(int)
if not os.path.isfile(jf_counts_fname):
print "Error: Cannot find jf counts file %s" %(jf_counts_fname)
sys.exit(1)
for fastx_entry in fastx_utils.get_fastx_entries(jf_counts_fname,
fasta=True):
kmer_count, kmer = fastx_entry
# Remove prefix '>' from FASTA entry
kmer_count = int(kmer_count[1:])
kmer_counts[kmer] = kmer_count
return kmer_counts
def output_dinuc_shuffled_fasta(fasta_fname,
shuffled_fasta_fname,
num_shuffles=1):
"""
Given a FASTA file, output a dinucleotide shuffled version of it.
"""
fasta_out = fastx_utils.write_open_fastx(shuffled_fasta_fname)
for fastx_entry in fastx_utils.get_fastx_entries(fasta_fname):
fastx_name, fastx_seq = fastx_entry
shuffled_recs = []
for shuffle_num in range(num_shuffles):
shuffled_seq = \
get_dinuc_shuffles(fastx_seq)[0]
shuffled_rec = (fastx_name, shuffled_seq)
shuffled_recs.append(shuffled_rec)
fasta_utils.write_fasta(fasta_out, shuffled_recs)
fasta_out.close()
def output_gff_event_seqs(event_ids, input_fasta_fname, output_fasta_fname,
entry_types=None,
suffixes=None,
remove_repeats=False):
"""
Given a set of event ids, pull out their sequences from an
input fasta filename and output these to a separate FASTA file.
Return the entries that were outputted.
- entry_types: optional list of entry types that should be outputted,
e.g. 'exon', 'intron'. Skip all entry types not within list.
- suffixes: optional list of suffixes that the first field of the
FASTA name should end in. For example, if the FASTA field is:
>event_id;part_id;entry_type
Then event_id must end in one of the suffixes for it to be
included.
"""
num_events = len(event_ids)
print "Retrieving sequences for %d events" %(num_events)
print " - Input FASTA: %s" %(input_fasta_fname)
print " - Output FASTA: %s" %(output_fasta_fname)
def is_event_fasta(fasta_name):
"""
Return true if the event is a FASTA one.
"""
# If there's any event such that the
# FASTA record starts with that event's name, then
# the FASTA record should be outputted
return len(filter(lambda e: \
fasta_name.startswith(e),
event_ids)) > 0
kept_fasta_entries = []
with open(output_fasta_fname, "w") as fasta_out:
for entry in fastx_utils.get_fastx_entries(input_fasta_fname):
fasta_name, fasta_seq = entry
fasta_name_fields = fasta_name.split(";")
entry_type = fasta_name_fields[2]
if is_event_fasta(fasta_name[1:]):
# If given entry types, check that this sequence
# is of one of the right entry types; otherwise
# skip it
if (entry_types is not None) and \
(entry_type not in entry_types):
# Not of correct entry type
continue
# If given suffixes, check that the first field
# of the FASTA name ends in one of the suffixes
if suffixes is not None:
if not any([fasta_name_fields[0].endswith(s) \
for s in suffixes]):
# The first FASTA name field does not end
# in any of the suffixes, so skip it.
continue
# If asked, remove repeats from sequence
if remove_repeats:
repeatless_seq = \
fasta_seq.translate(None, string.ascii_lowercase)
if len(repeatless_seq) == 0:
print "%s is all repeat! Not removing" %(fasta_name)
continue
fasta_seq = repeatless_seq
fasta_out.write("%s\n" %(fasta_name))
fasta_out.write("%s\n" %(fasta_seq))
kept_fasta_entries.append(fasta_name)
print "Outputted %d entries." %(len(kept_fasta_entries))
return kept_fasta_entries
