def main(cmdlineargs=None, default_outfile=sys.stdout):
"""
Main function that evaluates command-line parameters and iterates
over all reads.
default_outfile is the file to which trimmed reads are sent if the ``-o``
parameter is not used.
"""
parser = get_option_parser()
if cmdlineargs is None:
cmdlineargs = sys.argv[1:]
options, args = parser.parse_args(args=cmdlineargs)
# Setup logging only if there are not already any handlers (can happen when
# this function is being called externally such as from unit tests)
if not logging.root.handlers:
setup_logging(stdout=bool(options.output), quiet=options.quiet)
if len(args) == 0:
parser.error(
"At least one parameter needed: name of a FASTA or FASTQ file.")
elif len(args) > 2:
parser.error("Too many parameters.")
input_filename = args[0]
if input_filename.endswith('.qual'):
parser.error(
"If a .qual file is given, it must be the second argument.")
# Find out which 'mode' we need to use.
# Default: single-read trimming (neither -p nor -A/-G/-B/-U/--interleaved given)
paired = False
if options.paired_output:
# Modify first read only, keep second in sync (-p given, but not -A/-G/-B/-U).
# This exists for backwards compatibility ('legacy mode').
paired = 'first'
# Any of these options switch off legacy mode
if (options.adapters2 or options.front2 or options.anywhere2
or options.cut2 or options.interleaved or options.pair_filter
or options.too_short_paired_output
or options.too_long_paired_output):
# Full paired-end trimming when both -p and -A/-G/-B/-U given
# Read modifications (such as quality trimming) are applied also to second read.
paired = 'both'
if paired and len(args) == 1 and not options.interleaved:
parser.error("When paired-end trimming is enabled via -A/-G/-B/-U/"
"--interleaved or -p, two input files are required.")
if not paired:
if options.untrimmed_paired_output:
parser.error(
"Option --untrimmed-paired-output can only be used when "
"trimming paired-end reads (with option -p).")
interleaved_input = False
interleaved_output = False
if options.interleaved:
interleaved_input = len(args) == 1
interleaved_output = not options.paired_output
if not interleaved_input and not interleaved_output:
parser.error(
"When --interleaved is used, you cannot provide both two input files and two output files"
)
# Assign input_paired_filename and quality_filename
input_paired_filename = None
quality_filename = None
if paired:
if not interleaved_input:
input_paired_filename = args[1]
if not interleaved_output:
if not options.paired_output:
parser.error(
"When paired-end trimming is enabled via -A/-G/-B/-U, "
"a second output file needs to be specified via -p (--paired-output)."
)
if not options.output:
parser.error(
"When you use -p or --paired-output, you must also "
"use the -o option.")
if bool(options.untrimmed_output) != bool(
options.untrimmed_paired_output):
parser.error(
"When trimming paired-end reads, you must use either none "
"or both of the --untrimmed-output/--untrimmed-paired-output options."
)
if options.too_short_output and not options.too_short_paired_output:
parser.error(
"When using --too-short-output with paired-end "
"reads, you also need to use --too-short-paired-output")
if options.too_long_output and not options.too_long_paired_output:
parser.error(
"When using --too-long-output with paired-end "
"reads, you also need to use --too-long-paired-output")
elif len(args) == 2:
quality_filename = args[1]
if options.format is not None:
parser.error(
"If a pair of .fasta and .qual files is given, the -f/--format parameter cannot be used."
)
if options.format is not None and options.format.lower() not in [
'fasta', 'fastq', 'sra-fastq'
]:
parser.error(
"The input file format must be either 'fasta', 'fastq' or "
"'sra-fastq' (not '{0}').".format(options.format))
# Open input file(s)
try:
reader = seqio.open(input_filename,
file2=input_paired_filename,
qualfile=quality_filename,
colorspace=options.colorspace,
fileformat=options.format,
interleaved=interleaved_input)
except (seqio.UnknownFileType, IOError) as e:
parser.error(e)
if options.quality_cutoff is not None:
cutoffs = options.quality_cutoff.split(',')
if len(cutoffs) == 1:
try:
cutoffs = [0, int(cutoffs[0])]
except ValueError as e:
parser.error(
"Quality cutoff value not recognized: {0}".format(e))
elif len(cutoffs) == 2:
try:
cutoffs = [int(cutoffs[0]), int(cutoffs[1])]
except ValueError as e:
parser.error(
"Quality cutoff value not recognized: {0}".format(e))
else:
parser.error(
"Expected one value or two values separated by comma for the quality cutoff"
)
else:
cutoffs = None
open_writer = functools.partial(seqio.open,
mode='w',
qualities=reader.delivers_qualities,
colorspace=options.colorspace)
if options.pair_filter is None:
options.pair_filter = 'any'
min_affected = 2 if options.pair_filter == 'both' else 1
if not paired:
filter_wrapper = Redirector
elif paired == 'first':
filter_wrapper = LegacyPairedRedirector
elif paired == 'both':
filter_wrapper = functools.partial(PairedRedirector,
min_affected=min_affected)
filters = []
# TODO open_files = []
too_short_writer = None # too short reads go here
# TODO pass file name to TooShortReadFilter, add a .close() method?
if options.minimum_length > 0:
if options.too_short_output:
too_short_writer = open_writer(options.too_short_output,
options.too_short_paired_output)
filters.append(
filter_wrapper(too_short_writer,
TooShortReadFilter(options.minimum_length)))
too_long_writer = None # too long reads go here
if options.maximum_length < sys.maxsize:
if options.too_long_output is not None:
too_long_writer = open_writer(options.too_long_output,
options.too_long_paired_output)
filters.append(
filter_wrapper(too_long_writer,
TooLongReadFilter(options.maximum_length)))
if options.max_n != -1:
filters.append(filter_wrapper(None, NContentFilter(options.max_n)))
if int(options.discard_trimmed) + int(options.discard_untrimmed) + int(
options.untrimmed_output is not None) > 1:
parser.error(
"Only one of the --discard-trimmed, --discard-untrimmed "
"and --untrimmed-output options can be used at the same time.")
demultiplexer = None
untrimmed_writer = None
writer = None
if options.output is not None and '{name}' in options.output:
if options.discard_trimmed:
parser.error("Do not use --discard-trimmed when demultiplexing.")
if paired:
parser.error(
"Demultiplexing not supported for paired-end files, yet.")
untrimmed = options.output.replace('{name}', 'unknown')
if options.untrimmed_output:
untrimmed = options.untrimmed_output
if options.discard_untrimmed:
untrimmed = None
demultiplexer = Demultiplexer(options.output,
untrimmed,
qualities=reader.delivers_qualities,
colorspace=options.colorspace)
filters.append(demultiplexer)
else:
# Set up the remaining filters to deal with --discard-trimmed,
# --discard-untrimmed and --untrimmed-output. These options
# are mutually exclusive in order to avoid brain damage.
if options.discard_trimmed:
filters.append(filter_wrapper(None, DiscardTrimmedFilter()))
elif options.discard_untrimmed:
filters.append(filter_wrapper(None, DiscardUntrimmedFilter()))
elif options.untrimmed_output:
untrimmed_writer = open_writer(options.untrimmed_output,
options.untrimmed_paired_output)
filters.append(
filter_wrapper(untrimmed_writer, DiscardUntrimmedFilter()))
# Finally, figure out where the reads that passed all the previous
# filters should go.
if options.output is not None:
writer = open_writer(options.output,
options.paired_output,
interleaved=interleaved_output)
else:
writer = open_writer(default_outfile,
interleaved=interleaved_output)
if not paired:
filters.append(NoFilter(writer))
else:
filters.append(PairedNoFilter(writer))
if options.maq:
options.colorspace = True
options.double_encode = True
options.trim_primer = True
options.strip_suffix.append('_F3')
options.suffix = "/1"
if options.zero_cap is None:
options.zero_cap = options.colorspace
if options.trim_primer and not options.colorspace:
parser.error("Trimming the primer makes only sense in colorspace.")
if options.double_encode and not options.colorspace:
parser.error("Double-encoding makes only sense in colorspace.")
if options.anywhere and options.colorspace:
parser.error(
"Using --anywhere with colorspace reads is currently not supported (if you think this may be useful, contact the author)."
)
if not (0 <= options.error_rate <= 1.):
parser.error("The maximum error rate must be between 0 and 1.")
if options.overlap < 1:
parser.error("The overlap must be at least 1.")
if options.rest_file is not None:
options.rest_file = xopen(options.rest_file, 'w')
rest_writer = RestFileWriter(options.rest_file)
else:
rest_writer = None
if options.info_file is not None:
options.info_file = xopen(options.info_file, 'w')
if options.wildcard_file is not None:
options.wildcard_file = xopen(options.wildcard_file, 'w')
if options.colorspace:
if options.match_read_wildcards:
parser.error('IUPAC wildcards not supported in colorspace')
options.match_adapter_wildcards = False
adapter_parser = AdapterParser(
colorspace=options.colorspace,
max_error_rate=options.error_rate,
min_overlap=options.overlap,
read_wildcards=options.match_read_wildcards,
adapter_wildcards=options.match_adapter_wildcards,
indels=options.indels)
try:
adapters = adapter_parser.parse_multi(options.adapters,
options.anywhere, options.front)
adapters2 = adapter_parser.parse_multi(options.adapters2,
options.anywhere2,
options.front2)
except IOError as e:
if e.errno == errno.ENOENT:
parser.error(e)
raise
except ValueError as e:
parser.error(e)
if options.debug:
for adapter in adapters + adapters2:
adapter.enable_debug()
# Create the single-end processing pipeline (a list of "modifiers")
modifiers = []
if options.cut:
if len(options.cut) > 2:
parser.error("You cannot remove bases from more than two ends.")
if len(options.cut) == 2 and options.cut[0] * options.cut[1] > 0:
parser.error("You cannot remove bases from the same end twice.")
for cut in options.cut:
if cut != 0:
modifiers.append(UnconditionalCutter(cut))
if options.nextseq_trim is not None:
modifiers.append(
NextseqQualityTrimmer(options.nextseq_trim, options.quality_base))
if cutoffs:
modifiers.append(
QualityTrimmer(cutoffs[0], cutoffs[1], options.quality_base))
if adapters:
adapter_cutter = AdapterCutter(adapters, options.times,
options.wildcard_file,
options.info_file, rest_writer,
options.action)
modifiers.append(adapter_cutter)
# Modifiers that apply to both reads of paired-end reads unless in legacy mode
modifiers_both = []
if options.length is not None:
modifiers_both.append(Shortener(options.length))
if options.trim_n:
modifiers_both.append(NEndTrimmer())
if options.length_tag:
modifiers_both.append(LengthTagModifier(options.length_tag))
if options.strip_f3:
options.strip_suffix.append('_F3')
for suffix in options.strip_suffix:
modifiers_both.append(SuffixRemover(suffix))
if options.prefix or options.suffix:
modifiers_both.append(PrefixSuffixAdder(options.prefix,
options.suffix))
if options.double_encode:
modifiers_both.append(DoubleEncoder())
if options.zero_cap and reader.delivers_qualities:
modifiers_both.append(ZeroCapper(quality_base=options.quality_base))
if options.trim_primer:
modifiers_both.append(PrimerTrimmer)
modifiers.extend(modifiers_both)
# For paired-end data, create a second processing pipeline.
# However, if no second-read adapters were given (via -A/-G/-B/-U), we need to
# be backwards compatible and *no modifications* are done to the second read.
modifiers2 = []
if paired == 'both':
if options.cut2:
if len(options.cut2) > 2:
parser.error(
"You cannot remove bases from more than two ends.")
if len(options.cut2
) == 2 and options.cut2[0] * options.cut2[1] > 0:
parser.error(
"You cannot remove bases from the same end twice.")
for cut in options.cut2:
if cut != 0:
modifiers2.append(UnconditionalCutter(cut))
if cutoffs:
modifiers2.append(
QualityTrimmer(cutoffs[0], cutoffs[1], options.quality_base))
if adapters2:
adapter_cutter2 = AdapterCutter(adapters2, options.times, None,
None, None, options.action)
modifiers2.append(adapter_cutter2)
else:
adapter_cutter2 = None
modifiers2.extend(modifiers_both)
if paired:
pipeline = PairedEndPipeline(reader, modifiers, modifiers2, filters)
else:
pipeline = SingleEndPipeline(reader, modifiers, filters)
logger.info("This is cutadapt %s with Python %s", __version__,
platform.python_version())
logger.info("Command line parameters: %s", " ".join(cmdlineargs))
logger.info(
"Trimming %s adapter%s with at most %.1f%% errors in %s mode ...",
len(adapters) + len(adapters2),
's' if len(adapters) + len(adapters2) != 1 else '',
options.error_rate * 100, {
False: 'single-end',
'first': 'paired-end legacy',
'both': 'paired-end'
}[paired])
if paired == 'first' and (modifiers_both or cutoffs):
logger.warning('\n'.join(
textwrap.wrap(
'WARNING: Requested read '
'modifications are applied only to the first '
'read since backwards compatibility mode is enabled. '
'To modify both reads, also use any of the -A/-B/-G/-U options. '
'Use a dummy adapter sequence when necessary: -A XXX')))
start_time = time.clock()
try:
stats = pipeline.run()
except KeyboardInterrupt as e:
print("Interrupted", file=sys.stderr)
sys.exit(130)
except IOError as e:
if e.errno == errno.EPIPE:
sys.exit(1)
raise
except (seqio.FormatError, EOFError) as e:
sys.exit("cutadapt: error: {0}".format(e))
# close open files
for f in [
writer, untrimmed_writer, options.rest_file, options.wildcard_file,
options.info_file, too_short_writer, too_long_writer,
options.info_file, demultiplexer
]:
if f is not None and f is not sys.stdin and f is not sys.stdout:
f.close()
elapsed_time = time.clock() - start_time
if not options.quiet:
stats.collect((adapters, adapters2), elapsed_time, modifiers,
modifiers2, filters)
# send statistics to stderr if result was sent to stdout
stat_file = sys.stderr if options.output is None else None
with redirect_standard_output(stat_file):
print_report(stats, (adapters, adapters2))
def pipeline_from_parsed_args(options, args, default_outfile):
"""
Setup a processing pipeline from parsed command-line options.
If there are any problems parsing the arguments, a CommandlineError is thrown.
"""
if len(args) == 0:
raise CommandlineError("At least one parameter needed: name of a FASTA or FASTQ file.")
elif len(args) > 2:
raise CommandlineError("Too many parameters.")
input_filename = args[0]
if input_filename.endswith('.qual'):
raise CommandlineError("If a .qual file is given, it must be the second argument.")
# Find out which 'mode' we need to use.
# Default: single-read trimming (neither -p nor -A/-G/-B/-U/--interleaved given)
paired = False
if options.paired_output:
# Modify first read only, keep second in sync (-p given, but not -A/-G/-B/-U).
# This exists for backwards compatibility ('legacy mode').
paired = 'first'
# Any of these options switch off legacy mode
if (options.adapters2 or options.front2 or options.anywhere2 or
options.cut2 or options.interleaved or options.pair_filter or
options.too_short_paired_output or options.too_long_paired_output):
# Full paired-end trimming when both -p and -A/-G/-B/-U given
# Read modifications (such as quality trimming) are applied also to second read.
paired = 'both'
if paired and len(args) == 1 and not options.interleaved:
raise CommandlineError("When paired-end trimming is enabled via -A/-G/-B/-U/"
"--interleaved or -p, two input files are required.")
if not paired:
if options.untrimmed_paired_output:
raise CommandlineError("Option --untrimmed-paired-output can only be used when "
"trimming paired-end reads (with option -p).")
interleaved_input = False
interleaved_output = False
if options.interleaved:
interleaved_input = len(args) == 1
interleaved_output = not options.paired_output
if not interleaved_input and not interleaved_output:
raise CommandlineError("When --interleaved is used, you cannot provide both two input files and two output files")
# Assign input_paired_filename and quality_filename
input_paired_filename = None
quality_filename = None
if paired:
if not interleaved_input:
input_paired_filename = args[1]
if not interleaved_output:
if not options.paired_output:
raise CommandlineError("When paired-end trimming is enabled via -A/-G/-B/-U, "
"a second output file needs to be specified via -p (--paired-output).")
if not options.output:
raise CommandlineError("When you use -p or --paired-output, you must also "
"use the -o option.")
if bool(options.untrimmed_output) != bool(options.untrimmed_paired_output):
raise CommandlineError("When trimming paired-end reads, you must use either none "
"or both of the --untrimmed-output/--untrimmed-paired-output options.")
if options.too_short_output and not options.too_short_paired_output:
raise CommandlineError("When using --too-short-output with paired-end "
"reads, you also need to use --too-short-paired-output")
if options.too_long_output and not options.too_long_paired_output:
raise CommandlineError("When using --too-long-output with paired-end "
"reads, you also need to use --too-long-paired-output")
elif len(args) == 2:
quality_filename = args[1]
if options.format is not None:
raise CommandlineError("If a pair of .fasta and .qual files is given, the -f/--format parameter cannot be used.")
if options.format is not None and options.format.lower() not in ['fasta', 'fastq', 'sra-fastq']:
raise CommandlineError("The input file format must be either 'fasta', 'fastq' or "
"'sra-fastq' (not '{0}').".format(options.format))
# Open input file(s)
try:
reader = seqio.open(input_filename, file2=input_paired_filename,
qualfile=quality_filename, colorspace=options.colorspace,
fileformat=options.format, interleaved=interleaved_input)
except (seqio.UnknownFileType, IOError) as e:
raise CommandlineError(e)
if options.quality_cutoff is not None:
cutoffs = options.quality_cutoff.split(',')
if len(cutoffs) == 1:
try:
cutoffs = [0, int(cutoffs[0])]
except ValueError as e:
raise CommandlineError("Quality cutoff value not recognized: {0}".format(e))
elif len(cutoffs) == 2:
try:
cutoffs = [int(cutoffs[0]), int(cutoffs[1])]
except ValueError as e:
raise CommandlineError("Quality cutoff value not recognized: {0}".format(e))
else:
raise CommandlineError("Expected one value or two values separated by comma for the quality cutoff")
else:
cutoffs = None
open_writer = functools.partial(seqio.open, mode='w',
qualities=reader.delivers_qualities, colorspace=options.colorspace)
if options.pair_filter is None:
options.pair_filter = 'any'
min_affected = 2 if options.pair_filter == 'both' else 1
if not paired:
filter_wrapper = Redirector
elif paired == 'first':
filter_wrapper = LegacyPairedRedirector
elif paired == 'both':
filter_wrapper = functools.partial(PairedRedirector, min_affected=min_affected)
filters = []
# TODO open_files = []
too_short_writer = None # too short reads go here
# TODO pass file name to TooShortReadFilter, add a .close() method?
if options.minimum_length > 0:
if options.too_short_output:
too_short_writer = open_writer(options.too_short_output, options.too_short_paired_output)
filters.append(filter_wrapper(too_short_writer, TooShortReadFilter(options.minimum_length)))
too_long_writer = None # too long reads go here
if options.maximum_length < sys.maxsize:
if options.too_long_output is not None:
too_long_writer = open_writer(options.too_long_output, options.too_long_paired_output)
filters.append(filter_wrapper(too_long_writer, TooLongReadFilter(options.maximum_length)))
if options.max_n != -1:
filters.append(filter_wrapper(None, NContentFilter(options.max_n)))
if int(options.discard_trimmed) + int(options.discard_untrimmed) + int(options.untrimmed_output is not None) > 1:
raise CommandlineError("Only one of the --discard-trimmed, --discard-untrimmed "
"and --untrimmed-output options can be used at the same time.")
demultiplexer = None
untrimmed_writer = None
writer = None
if options.output is not None and '{name}' in options.output:
if options.discard_trimmed:
raise CommandlineError("Do not use --discard-trimmed when demultiplexing.")
if paired:
raise CommandlineError("Demultiplexing not supported for paired-end files, yet.")
untrimmed = options.output.replace('{name}', 'unknown')
if options.untrimmed_output:
untrimmed = options.untrimmed_output
if options.discard_untrimmed:
untrimmed = None
demultiplexer = Demultiplexer(options.output, untrimmed,
qualities=reader.delivers_qualities, colorspace=options.colorspace)
filters.append(demultiplexer)
else:
# Set up the remaining filters to deal with --discard-trimmed,
# --discard-untrimmed and --untrimmed-output. These options
# are mutually exclusive in order to avoid brain damage.
if options.discard_trimmed:
filters.append(filter_wrapper(None, DiscardTrimmedFilter()))
elif options.discard_untrimmed:
filters.append(filter_wrapper(None, DiscardUntrimmedFilter()))
elif options.untrimmed_output:
untrimmed_writer = open_writer(options.untrimmed_output,
options.untrimmed_paired_output)
filters.append(filter_wrapper(untrimmed_writer, DiscardUntrimmedFilter()))
# Finally, figure out where the reads that passed all the previous
# filters should go.
if options.output is not None:
writer = open_writer(options.output, options.paired_output, interleaved=interleaved_output)
else:
writer = open_writer(default_outfile, interleaved=interleaved_output)
if not paired:
filters.append(NoFilter(writer))
else:
filters.append(PairedNoFilter(writer))
if options.maq:
options.colorspace = True
options.double_encode = True
options.trim_primer = True
options.strip_suffix.append('_F3')
options.suffix = "/1"
if options.zero_cap is None:
options.zero_cap = options.colorspace
if options.trim_primer and not options.colorspace:
raise CommandlineError("Trimming the primer makes only sense in colorspace.")
if options.double_encode and not options.colorspace:
raise CommandlineError("Double-encoding makes only sense in colorspace.")
if options.anywhere and options.colorspace:
raise CommandlineError("Using --anywhere with colorspace reads is currently not supported (if you think this may be useful, contact the author).")
if not (0 <= options.error_rate <= 1.):
raise CommandlineError("The maximum error rate must be between 0 and 1.")
if options.overlap < 1:
raise CommandlineError("The overlap must be at least 1.")
if options.rest_file is not None:
options.rest_file = xopen(options.rest_file, 'w')
rest_writer = RestFileWriter(options.rest_file)
else:
rest_writer = None
if options.info_file is not None:
options.info_file = xopen(options.info_file, 'w')
if options.wildcard_file is not None:
options.wildcard_file = xopen(options.wildcard_file, 'w')
if options.colorspace:
if options.match_read_wildcards:
raise CommandlineError('IUPAC wildcards not supported in colorspace')
options.match_adapter_wildcards = False
adapter_parser = AdapterParser(
colorspace=options.colorspace,
max_error_rate=options.error_rate,
min_overlap=options.overlap,
read_wildcards=options.match_read_wildcards,
adapter_wildcards=options.match_adapter_wildcards,
indels=options.indels)
try:
adapters = adapter_parser.parse_multi(options.adapters, options.anywhere, options.front)
adapters2 = adapter_parser.parse_multi(options.adapters2, options.anywhere2, options.front2)
except IOError as e:
if e.errno == errno.ENOENT:
raise CommandlineError(e)
raise
except ValueError as e:
raise CommandlineError(e)
if options.debug:
for adapter in adapters + adapters2:
adapter.enable_debug()
# Create the single-end processing pipeline (a list of "modifiers")
modifiers = []
if options.cut:
if len(options.cut) > 2:
raise CommandlineError("You cannot remove bases from more than two ends.")
if len(options.cut) == 2 and options.cut[0] * options.cut[1] > 0:
raise CommandlineError("You cannot remove bases from the same end twice.")
for cut in options.cut:
if cut != 0:
modifiers.append(UnconditionalCutter(cut))
if options.nextseq_trim is not None:
modifiers.append(NextseqQualityTrimmer(options.nextseq_trim, options.quality_base))
if cutoffs:
modifiers.append(QualityTrimmer(cutoffs[0], cutoffs[1], options.quality_base))
if adapters:
adapter_cutter = AdapterCutter(adapters, options.times,
options.wildcard_file, options.info_file,
rest_writer, options.action)
modifiers.append(adapter_cutter)
# Modifiers that apply to both reads of paired-end reads unless in legacy mode
modifiers_both = []
if options.length is not None:
modifiers_both.append(Shortener(options.length))
if options.trim_n:
modifiers_both.append(NEndTrimmer())
if options.length_tag:
modifiers_both.append(LengthTagModifier(options.length_tag))
if options.strip_f3:
options.strip_suffix.append('_F3')
for suffix in options.strip_suffix:
modifiers_both.append(SuffixRemover(suffix))
if options.prefix or options.suffix:
modifiers_both.append(PrefixSuffixAdder(options.prefix, options.suffix))
if options.double_encode:
modifiers_both.append(DoubleEncoder())
if options.zero_cap and reader.delivers_qualities:
modifiers_both.append(ZeroCapper(quality_base=options.quality_base))
if options.trim_primer:
modifiers_both.append(PrimerTrimmer)
modifiers.extend(modifiers_both)
# For paired-end data, create a second processing pipeline.
# However, if no second-read adapters were given (via -A/-G/-B/-U), we need to
# be backwards compatible and *no modifications* are done to the second read.
modifiers2 = []
if paired == 'both':
if options.cut2:
if len(options.cut2) > 2:
raise CommandlineError("You cannot remove bases from more than two ends.")
if len(options.cut2) == 2 and options.cut2[0] * options.cut2[1] > 0:
raise CommandlineError("You cannot remove bases from the same end twice.")
for cut in options.cut2:
if cut != 0:
modifiers2.append(UnconditionalCutter(cut))
if cutoffs:
modifiers2.append(QualityTrimmer(cutoffs[0], cutoffs[1], options.quality_base))
if adapters2:
adapter_cutter2 = AdapterCutter(adapters2, options.times,
None, None, None, options.action)
modifiers2.append(adapter_cutter2)
modifiers2.extend(modifiers_both)
if paired:
pipeline = PairedEndPipeline(adapters, adapters2, reader, modifiers, modifiers2, filters)
else:
pipeline = SingleEndPipeline(adapters, adapters2, reader, modifiers, filters)
# TODO the following should be done some other way
pipeline.paired = paired
pipeline.error_rate = options.error_rate
pipeline.should_print_warning = paired == 'first' and (modifiers_both or cutoffs)
for f in [writer, untrimmed_writer,
options.rest_file, options.wildcard_file,
options.info_file, too_short_writer, too_long_writer,
options.info_file, demultiplexer]:
pipeline.register_file_to_close(f)
return pipeline