def split_paired_end(matcher, fastq_pairs, base_name=None, output_dir=None):
"""
Split reads from paired end data
For each fastq file pair in 'fastqs', check reads against the
index sequences in the BarcodeMatcher 'matcher' and write to an
appropriate file.
Arguments:
matcher (BarcodeMatcher): barcoder matcher instance
fastqs (list): list of Fastq pairs to split
base_name (str): optional, base name to use for output
Fastq files
output_dir (str): optional, path to directory to write
output Fastqs to
"""
if base_name is None:
base_name = ''
else:
base_name = "%s." % base_name
fp = OutputFiles(base_dir=output_dir)
for barcode in matcher.sequences:
fp.open((barcode, 'R1'), "%s%s_R1.fastq" % (base_name, barcode))
fp.open((barcode, 'R2'), "%s%s_R2.fastq" % (base_name, barcode))
fp.open(('undetermined', 'R1'), "%sundetermined_R1.fastq" % base_name)
fp.open(('undetermined', 'R2'), "%sundetermined_R2.fastq" % base_name)
# Filter reads
nread = 0
for fq_r1, fq_r2 in fastq_pairs:
print("Processing reads from fastq pair %s %s" % (fq_r1, fq_r2))
for read1, read2 in zip(FASTQFile.FastqIterator(fq_r1),
FASTQFile.FastqIterator(fq_r2)):
nread += 1
seq = read1.seqid.index_sequence
if not seq:
raise Exception("%s: no index sequence for read %d" %
(fq_r1, nread))
if seq != read2.seqid.index_sequence:
raise Exception("Index sequence mismatch between R1 and "
"R2 reads")
assigned_index = matcher.match(seq)
# Read not assigned
if assigned_index is None:
assigned_index = 'undetermined'
logging.debug("Assigned read #%d to %s" % (nread, assigned_index))
fp.write((assigned_index, 'R1'), read1)
fp.write((assigned_index, 'R2'), read2)
print("Finished (%d read pairs processed)" % nread)
def count_barcodes_for_file(fastq):
"""Count the index sequences across a single Fastq file
Arguments:
fastq: Fastq file to read barcodes from
Returns:
'counts' dictionary where counts[SEQ] holds the number of
times index sequence SEQ occurs.
"""
counts = dict()
nreads = 0
print "Reading in data from %s" % fastq
for read in FASTQFile.FastqIterator(fastq):
seq = read.seqid.index_sequence
if not seq:
raise ValueError,"No index sequence for read! %s" % read
# Check if we've already encountered this sequence
if seq in counts:
# Already seen
counts[seq] += 1
else:
# Novel sequence
counts[seq] = 1
# Return the counts dictionary
return counts
def stats(fastq_file):
"""Generate basic stats from FASTQ file
"""
# Loop over all reads in the FASTQ
n_reads = 0
read_lengths = {}
index_sequences = {}
for read in FASTQFile.FastqIterator(fastq_file):
# Count of reads
n_reads += 1
# Read length distribution
read_len = len(read.sequence)
if read_len in read_lengths:
read_lengths[read_len] += 1
else:
read_lengths[read_len] = 1
# Tag name distribution
index_seq = read.seqid.index_sequence
if index_seq is not None:
if index_seq in index_sequences:
index_sequences[index_seq] += 1
else:
index_sequences[index_seq] = 1
# Finished
print "Total reads: %d" % n_reads
print "Read lengths"
for len_ in read_lengths:
print "\t%d: %d" % (len_, read_lengths[len_])
print "Index sequences"
for seq in index_sequences:
print "\t%s: %d" % (seq, index_sequences[seq])
def split_single_end(matcher, fastqs, base_name=None, output_dir=None):
"""Split reads from single ended data
For each fastq file in 'fastqs', check reads against the index
sequences in the BarcodeMatcher 'matcher' and write to an
appropriate file.
"""
if base_name is None:
base_name = ''
else:
base_name = "%s." % base_name
fp = OutputFiles(base_dir=output_dir)
for barcode in matcher.sequences:
fp.open(barcode, "%s%s.fastq" % (base_name, barcode))
fp.open('undetermined', "%sundetermined.fastq" % base_name)
# Filter reads
nread = 0
for fastq in fastqs:
print "Processing reads from %s" % fastq
for read in FASTQFile.FastqIterator(fastq):
nread += 1
seq = read.seqid.index_sequence
if not seq:
logging.error("No index sequence for read!")
sys.exit(1)
assigned_index = matcher.match(seq)
# Read not assigned
if assigned_index is None:
assigned_index = 'undetermined'
logging.debug("Assigned read #%d to %s" % (nread, assigned_index))
fp.write(assigned_index, read)
print "Finished (%d reads processed)" % nread
def split_paired_end(matcher, fastq_pairs, base_name=None, output_dir=None):
"""Split reads from paired end data
For each fastq file pair in 'fastqs', check reads against the
index sequences in the BarcodeMatcher 'matcher' and write to an
appropriate file.
"""
if base_name is None:
base_name = ''
else:
base_name = "%s." % base_name
fp = OutputFiles(base_dir=output_dir)
for barcode in matcher.sequences:
fp.open((barcode, 'R1'), "%s%s_R1.fastq" % (base_name, barcode))
fp.open((barcode, 'R2'), "%s%s_R2.fastq" % (base_name, barcode))
fp.open(('undetermined', 'R1'), "%sundetermined_R1.fastq" % base_name)
fp.open(('undetermined', 'R2'), "%sundetermined_R2.fastq" % base_name)
# Filter reads
nread = 0
for fq_r1, fq_r2 in fastq_pairs:
print "Processing reads from fastq pair %s %s" % (fq_r1, fq_r2)
for read1, read2 in itertools.izip(FASTQFile.FastqIterator(fq_r1),
FASTQFile.FastqIterator(fq_r2)):
nread += 1
seq = read1.seqid.index_sequence
if not seq:
logging.error("No index sequence for read!")
sys.exit(1)
if seq != read2.seqid.index_sequence:
raise Exception, "Index sequence mismatch between R1 and R2 reads"
assigned_index = matcher.match(seq)
# Read not assigned
if assigned_index is None:
assigned_index = 'undetermined'
logging.debug("Assigned read #%d to %s" % (nread, assigned_index))
fp.write((assigned_index, 'R1'), read1)
fp.write((assigned_index, 'R2'), read2)
print "Finished (%d read pairs processed)" % nread
def edit_instrument_name(fastq_file, new_instrument_name):
"""Edit the instrument name for all records in FASTQ file
Loop over all records in a supplied FASTQ file, update the sequence identifier
(i.e. first line in the each record) by changing the instrument name, and write
the updated records to stdout.
"""
# Loop over all reads in the FASTQ
# Update the instrument name in the sequence identifier and echo to stdout
for read in FASTQFile.FastqIterator(fastq_file):
if new_instrument_name:
# Modify the instrument name
read.seqid.instrument_name = new_instrument_name
# Echo updated read to stdout
print read
def load(self, fastq=None, fp=None):
"""Read in fastq data and collect index sequence info
The input FASTQ can be either a text file or a compressed (gzipped)
FASTQ, specified via a file name (using the 'fastq' argument), or a
file-like object opened for line reading (using the 'fp' argument).
Arguments:
fastq_file: name of the FASTQ file to iterate through
fp: file-like object opened for reading
"""
for read in FASTQFile.FastqIterator(fastq_file=fastq, fp=fp):
seq = read.seqid.index_sequence
if seq not in self._counts:
self._counts[seq] = 1
else:
self._counts[seq] += 1
def fastqiterator(fastq=None, fp=None):
"""
Return number of reads in a FASTQ file
Uses the FASTQFile.FastqIterator class to do the
counting.
Arguments:
fastq: fastq(.gz) file
fp: open file descriptor for fastq file
Returns:
Number of reads
"""
nreads = 0
for r in FASTQFile.FastqIterator(fastq_file=fastq, fp=fp):
nreads += 1
return nreads
def split_single_end(matcher, fastqs, base_name=None, output_dir=None):
"""
Split reads from single ended data
For each fastq file in 'fastqs', check reads against the index
sequences in the BarcodeMatcher 'matcher' and write to an
appropriate file.
Arguments:
matcher (BarcodeMatcher): barcoder matcher instance
fastqs (list): list of Fastqs to split
base_name (str): optional, base name to use for output
Fastq files
output_dir (str): optional, path to directory to write
output Fastqs to
"""
if base_name is None:
base_name = ''
else:
base_name = "%s." % base_name
fp = OutputFiles(base_dir=output_dir)
for barcode in matcher.sequences:
fp.open(barcode, "%s%s.fastq" % (base_name, barcode))
fp.open('undetermined', "%sundetermined.fastq" % base_name)
# Filter reads
nread = 0
for fastq in fastqs:
print("Processing reads from %s" % fastq)
for read in FASTQFile.FastqIterator(fastq):
nread += 1
seq = read.seqid.index_sequence
if not seq:
raise Exception("%s: no index sequence for read %d" %
(fastq, nread))
assigned_index = matcher.match(seq)
# Read not assigned
if assigned_index is None:
assigned_index = 'undetermined'
logging.debug("Assigned read #%d to %s" % (nread, assigned_index))
fp.write(assigned_index, read)
print("Finished (%d reads processed)" % nread)
def reads_per_lane(fastq=None, fp=None):
"""
Return counts of reads in each lane of FASTQ file
Uses the FASTQFile.FastqIterator class to do the
counting, with counts split by lane.
Arguments:
fastq: fastq(.gz) file
fp: open file descriptor for fastq file
Returns:
Dictionary where keys are lane numbers (as integers)
and values are number of reads in that lane.
"""
nreads = {}
for r in FASTQFile.FastqIterator(fastq_file=fastq, fp=fp):
lane = int(r.seqid.flowcell_lane)
try:
nreads[lane] += 1
except KeyError:
nreads[lane] = 1
return nreads
# Main program
if __name__ == "__main__":
# Collect input fastq file name
if len(sys.argv) < 2:
print("Usage: %s fastq" % os.path.basename(sys.argv[0]))
sys.exit()
fastq = sys.argv[1]
# Output file names
fastq_out = fastq + ".paired"
singles_header = fastq + ".single.header"
pairs_header = fastq + ".pair.header"
# Loop over file and collect read names
headers = set()
pairs = set()
n = 1
for read in FASTQFile.FastqIterator(fastq):
seqid = str(read.seqid)
if seqid in headers:
# Part of a pair
pairs.add(seqid)
else:
headers.add(seqid)
n += 1
if not (n % 1000000): print("%s" % n)
# Loop again outputing only paired reads
fp = io.open(fastq_out, 'wt')
fp_singles = io.open(singles_header, 'wt')
fp_pairs = io.open(pairs_header, 'wt')
n = 1
for read in FASTQFile.FastqIterator(fastq):
seqid = str(read.seqid)
def demultiplex_fastq(fastq_file,barcodes,nmismatches):
"""Perform demultiplexing of a FASTQ file
Demultiplex reads in a FASTQ file given information about a set of
barcode/index sequences.
Produces a file for each barcode, plus another for 'unbinned'
reads.
Arguments:
fastq_file: FASTQ file to be demultiplexed (can be gzipped)
barcodes: list of barcode sequences to use for demultiplexing
nmismatches: maxiumum number of mismatched bases allowed when
testing whether barcode sequences match
Returns:
No return value
"""
# Start
print "Processing %s" % fastq_file
info = IlluminaData.IlluminaFastq(fastq_file)
# Set up output files
output_files = {}
# Weed out barcodes that aren't associated with this lane
local_barcodes = []
for barcode in barcodes:
if barcode['lane'] != info.lane_number:
continue
local_barcodes.append(barcode)
output_file_name = "%s_%s_L%03d_R%d_%03d.fastq" % (barcode['name'],
barcode['index'],
info.lane_number,
info.read_number,
info.set_number)
print "\t%s\t%s" % (barcode['index'],output_file_name)
if os.path.exists(output_file_name):
print "\t%s: already exists,exiting" % output_file_name
sys.exit(1)
output_files[barcode['index']] = open(output_file_name,'w')
# Check if there's anything to do
if len(local_barcodes) == 0:
return
# Also make a file for unbinned reads
unbinned_file_name = "unbinned_L%03d_R%d_%03d.fastq" % (info.lane_number,
info.read_number,
info.set_number)
if os.path.exists(unbinned_file_name):
print "\t%s: already exists,exiting" % unbinned_file_name
sys.exit(1)
output_files['unbinned'] = open(unbinned_file_name,'w')
# Process reads
nreads = 0
for read in FASTQFile.FastqIterator(fastq_file):
nreads += 1
matched_read = False
this_barcode = read.seqid.index_sequence
for barcode in local_barcodes:
if barcode['matcher'].match(this_barcode,nmismatches):
##print "Matched %s against %s" % (this_barcode,barcodes[barcode]['name'])
output_files[barcode['index']].write(str(read)+'\n')
matched_read = True
break
# Put in unbinned if no match
if not matched_read:
output_files['unbinned'].write(str(read)+'\n')
##if nreads > 100: break
# Close files
for barcode in local_barcodes:
output_files[barcode['index']].close()
print "\tMatched %d reads for %s" % (nreads,os.path.basename(fastq_file))
