Coverage for Bio.GenBank : 29%

Hot-keys on this page
r m x p toggle line displays
j k next/prev highlighted chunk
0 (zero) top of page
1 (one) first highlighted chunk
# Copyright 2000 by Jeffrey Chang, Brad Chapman. All rights reserved. # Copyright 2006-2013 by Peter Cock. All rights reserved. # # This code is part of the Biopython distribution and governed by its # license. Please see the LICENSE file that should have been included # as part of this package.
Rather than using Bio.GenBank, you are now encouraged to use Bio.SeqIO with the "genbank" or "embl" format names to parse GenBank or EMBL files into SeqRecord and SeqFeature objects (see the Biopython tutorial for details).
Using Bio.GenBank directly to parse GenBank files is only useful if you want to obtain GenBank-specific Record objects, which is a much closer representation to the raw file contents that the SeqRecord alternative from the FeatureParser (used in Bio.SeqIO).
To use the Bio.GenBank parser, there are two helper functions:
read Parse a handle containing a single GenBank record as Bio.GenBank specific Record objects. parse Iterate over a handle containing multiple GenBank records as Bio.GenBank specific Record objects.
The following internal classes are not intended for direct use and may be deprecated in a future release.
Classes: Iterator Iterate through a file of GenBank entries ErrorFeatureParser Catch errors caused during parsing. FeatureParser Parse GenBank data in SeqRecord and SeqFeature objects. RecordParser Parse GenBank data into a Record object.
Exceptions: ParserFailureError Exception indicating a failure in the parser (ie. scanner or consumer) LocationParserError Exception indiciating a problem with the spark based location parser.
"""
# other Biopython stuff
# other Bio.GenBank stuff
#Constants used to parse GenBank header lines
#Constants for parsing GenBank feature lines
#Regular expressions for location parsing
% (_within_position, _within_position)
% (_oneof_position, _oneof_position)
% (_simple_location, _simple_location)) % (_pair_location, _solo_location, _between_location, _within_location, _oneof_location) % (_complex_location, _complex_location) % (_possibly_complemented_complex_location, _possibly_complemented_complex_location))
#Trans-spliced example from NC_016406, note underscore in reference name:
"""Build a Position object (PRIVATE).
For an end position, leave offset as zero (default):
>>> _pos("5") ExactPosition(5)
For a start position, set offset to minus one (for Python counting):
>>> _pos("5", -1) ExactPosition(4)
This also covers fuzzy positions:
>>> p = _pos("<5") >>> p BeforePosition(5) >>> print(p) <5 >>> int(p) 5
>>> _pos(">5") AfterPosition(5)
By default assumes an end position, so note the integer behaviour:
>>> p = _pos("one-of(5,8,11)") >>> p OneOfPosition(11, choices=[ExactPosition(5), ExactPosition(8), ExactPosition(11)]) >>> print(p) one-of(5,8,11) >>> int(p) 11
>>> _pos("(8.10)") WithinPosition(10, left=8, right=10)
Fuzzy start positions:
>>> p = _pos("<5", -1) >>> p BeforePosition(4) >>> print(p) <4 >>> int(p) 4
Notice how the integer behaviour changes too!
>>> p = _pos("one-of(5,8,11)", -1) >>> p OneOfPosition(4, choices=[ExactPosition(4), ExactPosition(7), ExactPosition(10)]) >>> print(p) one-of(4,7,10) >>> int(p) 4
""" if pos_str.startswith("<"): return SeqFeature.BeforePosition(int(pos_str[1:])+offset) elif pos_str.startswith(">"): return SeqFeature.AfterPosition(int(pos_str[1:])+offset) elif _re_within_position.match(pos_str): s, e = pos_str[1:-1].split(".") s = int(s) + offset e = int(e) + offset if offset == -1: default = s else: default = e return SeqFeature.WithinPosition(default, left=s, right=e) elif _re_oneof_position.match(pos_str): assert pos_str.startswith("one-of(") assert pos_str[-1]==")" parts = [SeqFeature.ExactPosition(int(pos)+offset) for pos in pos_str[7:-1].split(",")] if offset == -1: default = min(int(pos) for pos in parts) else: default = max(int(pos) for pos in parts) return SeqFeature.OneOfPosition(default, choices=parts) else: return SeqFeature.ExactPosition(int(pos_str)+offset)
"""FeatureLocation from non-compound non-complement location (PRIVATE).
Simple examples,
>>> _loc("123..456", 1000, +1) FeatureLocation(ExactPosition(122), ExactPosition(456), strand=1) >>> _loc("<123..>456", 1000, strand = -1) FeatureLocation(BeforePosition(122), AfterPosition(456), strand=-1)
A more complex location using within positions,
>>> _loc("(9.10)..(20.25)", 1000, 1) FeatureLocation(WithinPosition(8, left=8, right=9), WithinPosition(25, left=20, right=25), strand=1)
Notice how that will act as though it has overall start 8 and end 25.
Zero length between feature,
>>> _loc("123^124", 1000, 0) FeatureLocation(ExactPosition(123), ExactPosition(123), strand=0)
The expected sequence length is needed for a special case, a between position at the start/end of a circular genome:
>>> _loc("1000^1", 1000, 1) FeatureLocation(ExactPosition(1000), ExactPosition(1000), strand=1)
Apart from this special case, between positions P^Q must have P+1==Q,
>>> _loc("123^456", 1000, 1) Traceback (most recent call last): ... ValueError: Invalid between location '123^456' """ try: s, e = loc_str.split("..") except ValueError: assert ".." not in loc_str if "^" in loc_str: #A between location like "67^68" (one based counting) is a #special case (note it has zero length). In python slice #notation this is 67:67, a zero length slice. See Bug 2622 #Further more, on a circular genome of length N you can have #a location N^1 meaning the junction at the origin. See Bug 3098. #NOTE - We can imagine between locations like "2^4", but this #is just "3". Similarly, "2^5" is just "3..4" s, e = loc_str.split("^") if int(s)+1==int(e): pos = _pos(s) elif int(s)==expected_seq_length and e=="1": pos = _pos(s) else: raise ValueError("Invalid between location %s" % repr(loc_str)) return SeqFeature.FeatureLocation(pos, pos, strand) else: #e.g. "123" s = loc_str e = loc_str return SeqFeature.FeatureLocation(_pos(s, -1), _pos(e), strand)
"""Split a tricky compound location string (PRIVATE).
>>> list(_split_compound_loc("123..145")) ['123..145'] >>> list(_split_compound_loc("123..145,200..209")) ['123..145', '200..209'] >>> list(_split_compound_loc("one-of(200,203)..300")) ['one-of(200,203)..300'] >>> list(_split_compound_loc("complement(123..145),200..209")) ['complement(123..145)', '200..209'] >>> list(_split_compound_loc("123..145,one-of(200,203)..209")) ['123..145', 'one-of(200,203)..209'] >>> list(_split_compound_loc("123..145,one-of(200,203)..one-of(209,211),300")) ['123..145', 'one-of(200,203)..one-of(209,211)', '300'] >>> list(_split_compound_loc("123..145,complement(one-of(200,203)..one-of(209,211)),300")) ['123..145', 'complement(one-of(200,203)..one-of(209,211))', '300'] >>> list(_split_compound_loc("123..145,200..one-of(209,211),300")) ['123..145', '200..one-of(209,211)', '300'] >>> list(_split_compound_loc("123..145,200..one-of(209,211)")) ['123..145', '200..one-of(209,211)'] >>> list(_split_compound_loc("complement(149815..150200),complement(293787..295573),NC_016402.1:6618..6676,181647..181905")) ['complement(149815..150200)', 'complement(293787..295573)', 'NC_016402.1:6618..6676', '181647..181905'] """ if "one-of(" in compound_loc: #Hard case while "," in compound_loc: assert compound_loc[0] != "," assert compound_loc[0:2] != ".." i = compound_loc.find(",") part = compound_loc[:i] compound_loc = compound_loc[i:] # includes the comma while part.count("(") > part.count(")"): assert "one-of(" in part, (part, compound_loc) i = compound_loc.find(")") part += compound_loc[:i+1] compound_loc = compound_loc[i+1:] if compound_loc.startswith(".."): i = compound_loc.find(",") if i==-1: part += compound_loc compound_loc = "" else: part += compound_loc[:i] compound_loc = compound_loc[i:] # includes the comma while part.count("(") > part.count(")"): assert part.count("one-of(") == 2 i = compound_loc.find(")") part += compound_loc[:i+1] compound_loc = compound_loc[i+1:] if compound_loc.startswith(","): compound_loc = compound_loc[1:] assert part yield part if compound_loc: yield compound_loc else: #Easy case for part in compound_loc.split(","): yield part
"""Iterator interface to move over a file of GenBank entries one at a time (OBSOLETE).
This class is likely to be deprecated in a future release of Biopython. Please use Bio.SeqIO.parse(..., format="gb") or Bio.GenBank.parse(...) for SeqRecord and GenBank specific Record objects respectively instead. """ """Initialize the iterator.
Arguments: o handle - A handle with GenBank entries to iterate through. o parser - An optional parser to pass the entries through before returning them. If None, then the raw entry will be returned. """ self.handle = handle self._parser = parser
"""Return the next GenBank record from the handle.
Will return None if we ran out of records. """ if self._parser is None: lines = [] while True: line = self.handle.readline() if not line: return None # Premature end of file? lines.append(line) if line.rstrip() == "//": break return "".join(lines) try: return self._parser.parse(self.handle) except StopIteration: return None
"""Python 2 style alias for Python 3 style __next__ method.""" return self.__next__()
return iter(self.__next__, None)
"""Failure caused by some kind of problem in the parser. """
"""Could not Properly parse out a location from a GenBank file. """
"""Parse GenBank files into Seq + Feature objects (OBSOLETE).
Direct use of this class is discouraged, and may be deprecated in a future release of Biopython.
Please use Bio.SeqIO.parse(...) or Bio.SeqIO.read(...) instead. """ feature_cleaner = FeatureValueCleaner()): """Initialize a GenBank parser and Feature consumer.
Arguments: o debug_level - An optional argument that species the amount of debugging information the parser should spit out. By default we have no debugging info (the fastest way to do things), but if you want you can set this as high as two and see exactly where a parse fails. o use_fuzziness - Specify whether or not to use fuzzy representations. The default is 1 (use fuzziness). o feature_cleaner - A class which will be used to clean out the values of features. This class must implement the function clean_value. GenBank.utils has a "standard" cleaner class, which is used by default. """ self._scanner = GenBankScanner(debug_level) self.use_fuzziness = use_fuzziness self._cleaner = feature_cleaner
"""Parse the specified handle. """ self._consumer = _FeatureConsumer(self.use_fuzziness, self._cleaner) self._scanner.feed(handle, self._consumer) return self._consumer.data
"""Parse GenBank files into Record objects (OBSOLETE).
Direct use of this class is discouraged, and may be deprecated in a future release of Biopython.
Please use the Bio.GenBank.parse(...) or Bio.GenBank.read(...) functions instead. """ """Initialize the parser.
Arguments: o debug_level - An optional argument that species the amount of debugging information the parser should spit out. By default we have no debugging info (the fastest way to do things), but if you want you can set this as high as two and see exactly where a parse fails. """ self._scanner = GenBankScanner(debug_level)
"""Parse the specified handle into a GenBank record. """ self._consumer = _RecordConsumer()
self._scanner.feed(handle, self._consumer) return self._consumer.data
"""Abstract GenBank consumer providing useful general functions (PRIVATE).
This just helps to eliminate some duplication in things that most GenBank consumers want to do. """ # Special keys in GenBank records that we should remove spaces from # For instance, \translation keys have values which are proteins and # should have spaces and newlines removed from them. This class # attribute gives us more control over specific formatting problems.
pass
pass
return self._unhandled
"""Split a string of keywords into a nice clean list. """ # process the keywords into a python list if keyword_string == "" or keyword_string == ".": keywords = "" elif keyword_string[-1] == '.': keywords = keyword_string[:-1] else: keywords = keyword_string keyword_list = keywords.split(';') clean_keyword_list = [x.strip() for x in keyword_list] return clean_keyword_list
"""Split a string of accession numbers into a list. """ # first replace all line feeds with spaces # Also, EMBL style accessions are split with ';' accession = accession_string.replace("\n", " ").replace(";", " ")
return [x.strip() for x in accession.split() if x.strip()]
"""Split a string with taxonomy info into a list. """ if not taxonomy_string or taxonomy_string==".": #Missing data, no taxonomy return []
if taxonomy_string[-1] == '.': tax_info = taxonomy_string[:-1] else: tax_info = taxonomy_string tax_list = tax_info.split(';') new_tax_list = [] for tax_item in tax_list: new_items = tax_item.split("\n") new_tax_list.extend(new_items) while '' in new_tax_list: new_tax_list.remove('') clean_tax_list = [x.strip() for x in new_tax_list]
return clean_tax_list
"""Clean whitespace out of a location string.
The location parser isn't a fan of whitespace, so we clean it out before feeding it into the parser. """ #Originally this imported string.whitespace and did a replace #via a loop. It's simpler to just split on whitespace and rejoin #the string - and this avoids importing string too. See Bug 2684. return ''.join(location_string.split())
"""Remove any newlines in the passed text, returning the new string. """ # get rid of newlines in the qualifier value newlines = ["\n", "\r"] for ws in newlines: text = text.replace(ws, "")
return text
"""Replace multiple spaces in the passed text with single spaces. """ # get rid of excessive spaces return ' '.join(x for x in text.split(" ") if x)
"""Remove all spaces from the passed text. """ return text.replace(" ", "")
"""Convert a start and end range to python notation.
In GenBank, starts and ends are defined in "biological" coordinates, where 1 is the first base and [i, j] means to include both i and j.
In python, 0 is the first base and [i, j] means to include i, but not j.
So, to convert "biological" to python coordinates, we need to subtract 1 from the start, and leave the end and things should be converted happily. """ new_start = start - 1 new_end = end
return new_start, new_end
"""Create a SeqRecord object with Features to return (PRIVATE).
Attributes: o use_fuzziness - specify whether or not to parse with fuzziness in feature locations. o feature_cleaner - a class that will be used to provide specialized cleaning-up of feature values. """ from Bio.SeqRecord import SeqRecord _BaseGenBankConsumer.__init__(self) self.data = SeqRecord(None, id = None) self.data.id = None self.data.description = ""
self._use_fuzziness = use_fuzziness self._feature_cleaner = feature_cleaner
self._seq_type = '' self._seq_data = [] self._cur_reference = None self._cur_feature = None self._expected_size = None
"""Set the locus name is set as the name of the Sequence. """ self.data.name = locus_name
"""Record the sequence length.""" self._expected_size = int(content)
"""Record the sequence type so we can choose an appropriate alphabet. """ self._seq_type = type.strip()
self.data.annotations['data_file_division'] = division
self.data.annotations['date'] = submit_date
"""Set the definition as the description of the sequence. """ if self.data.description: #Append to any existing description #e.g. EMBL files with two DE lines. self.data.description += " " + definition else: self.data.description = definition
"""Set the accession number as the id of the sequence.
If we have multiple accession numbers, the first one passed is used. """ new_acc_nums = self._split_accessions(acc_num)
#Also record them ALL in the annotations try: #On the off chance there was more than one accession line: for acc in new_acc_nums: #Prevent repeat entries if acc not in self.data.annotations['accessions']: self.data.annotations['accessions'].append(acc) except KeyError: self.data.annotations['accessions'] = new_acc_nums
# if we haven't set the id information yet, add the first acc num if not self.data.id: if len(new_acc_nums) > 0: #self.data.id = new_acc_nums[0] #Use the FIRST accession as the ID, not the first on this line! self.data.id = self.data.annotations['accessions'][0]
self.data.annotations['wgs'] = content.split('-')
self.data.annotations.setdefault('wgs_scafld', []).append(content.split('-'))
self.data.annotations['nid'] = content
self.data.annotations['pid'] = content
#Want to use the versioned accession as the record.id #This comes from the VERSION line in GenBank files, or the #obsolete SV line in EMBL. For the new EMBL files we need #both the version suffix from the ID line and the accession #from the AC line. if version_id.count(".")==1 and version_id.split(".")[1].isdigit(): self.accession(version_id.split(".")[0]) self.version_suffix(version_id.split(".")[1]) elif version_id: #For backwards compatibility... self.data.id = version_id
"""Handle the information from the PROJECT line as a list of projects.
e.g. PROJECT GenomeProject:28471
or: PROJECT GenomeProject:13543 GenomeProject:99999
This is stored as dbxrefs in the SeqRecord to be consistent with the projected switch of this line to DBLINK in future GenBank versions. Note the NCBI plan to replace "GenomeProject:28471" with the shorter "Project:28471" as part of this transition. """ content = content.replace("GenomeProject:", "Project:") self.data.dbxrefs.extend(p for p in content.split() if p)
"""Store DBLINK cross references as dbxrefs in our record object.
This line type is expected to replace the PROJECT line in 2009. e.g.
During transition:
PROJECT GenomeProject:28471 DBLINK Project:28471 Trace Assembly Archive:123456
Once the project line is dropped:
DBLINK Project:28471 Trace Assembly Archive:123456
Note GenomeProject -> Project.
We'll have to see some real examples to be sure, but based on the above example we can expect one reference per line.
Note that at some point the NCBI have included an extra space, e.g.
DBLINK Project: 28471 """ #During the transition period with both PROJECT and DBLINK lines, #we don't want to add the same cross reference twice. while ": " in content: content = content.replace(": ", ":") if content.strip() not in self.data.dbxrefs: self.data.dbxrefs.append(content.strip())
"""Set the version to overwrite the id.
Since the verison provides the same information as the accession number, plus some extra info, we set this as the id if we have a version. """ #e.g. GenBank line: #VERSION U49845.1 GI:1293613 #or the obsolete EMBL line: #SV U49845.1 #Scanner calls consumer.version("U49845.1") #which then calls consumer.version_suffix(1) # #e.g. EMBL new line: #ID X56734; SV 1; linear; mRNA; STD; PLN; 1859 BP. #Scanner calls consumer.version_suffix(1) assert version.isdigit() self.data.annotations['sequence_version'] = int(version)
self.data.annotations['db_source'] = content.rstrip()
self.data.annotations['gi'] = content
if 'keywords' in self.data.annotations: #Multi-line keywords, append to list #Note EMBL states "A keyword is never split between lines." self.data.annotations['keywords'].extend(self._split_keywords(content)) else: self.data.annotations['keywords'] = self._split_keywords(content)
self.data.annotations['segment'] = content
#Note that some software (e.g. VectorNTI) may produce an empty #source (rather than using a dot/period as might be expected). if content == "": source_info = "" elif content[-1] == '.': source_info = content[:-1] else: source_info = content self.data.annotations['source'] = source_info
self.data.annotations['organism'] = content
"""Records (another line of) the taxonomy lineage. """ lineage = self._split_taxonomy(content) try: self.data.annotations['taxonomy'].extend(lineage) except KeyError: self.data.annotations['taxonomy'] = lineage
"""Signal the beginning of a new reference object. """ # if we have a current reference that hasn't been added to # the list of references, add it. if self._cur_reference is not None: self.data.annotations['references'].append(self._cur_reference) else: self.data.annotations['references'] = []
self._cur_reference = SeqFeature.Reference()
"""Attempt to determine the sequence region the reference entails.
Possible types of information we may have to deal with:
(bases 1 to 86436) (sites) (bases 1 to 105654; 110423 to 111122) 1 (residues 1 to 182) """ # first remove the parentheses or other junk ref_base_info = content[1:-1]
all_locations = [] # parse if we've got 'bases' and 'to' if 'bases' in ref_base_info and 'to' in ref_base_info: # get rid of the beginning 'bases' ref_base_info = ref_base_info[5:] locations = self._split_reference_locations(ref_base_info) all_locations.extend(locations) elif 'residues' in ref_base_info and 'to' in ref_base_info: residues_start = ref_base_info.find("residues") # get only the information after "residues" ref_base_info = ref_base_info[(residues_start + len("residues ")):] locations = self._split_reference_locations(ref_base_info) all_locations.extend(locations)
# make sure if we are not finding information then we have # the string 'sites' or the string 'bases' elif (ref_base_info == 'sites' or ref_base_info.strip() == 'bases'): pass # otherwise raise an error else: raise ValueError("Could not parse base info %s in record %s" % (ref_base_info, self.data.id))
self._cur_reference.location = all_locations
"""Get reference locations out of a string of reference information
The passed string should be of the form:
1 to 20; 20 to 100
This splits the information out and returns a list of location objects based on the reference locations. """ # split possibly multiple locations using the ';' all_base_info = location_string.split(';')
new_locations = [] for base_info in all_base_info: start, end = base_info.split('to') new_start, new_end = \ self._convert_to_python_numbers(int(start.strip()), int(end.strip())) this_location = SeqFeature.FeatureLocation(new_start, new_end) new_locations.append(this_location) return new_locations
if self._cur_reference.authors: self._cur_reference.authors += ' ' + content else: self._cur_reference.authors = content
if self._cur_reference.consrtm: self._cur_reference.consrtm += ' ' + content else: self._cur_reference.consrtm = content
if self._cur_reference is None: import warnings from Bio import BiopythonParserWarning warnings.warn("GenBank TITLE line without REFERENCE line.", BiopythonParserWarning) elif self._cur_reference.title: self._cur_reference.title += ' ' + content else: self._cur_reference.title = content
if self._cur_reference.journal: self._cur_reference.journal += ' ' + content else: self._cur_reference.journal = content
self._cur_reference.medline_id = content
self._cur_reference.pubmed_id = content
"""Deal with a reference comment.""" if self._cur_reference.comment: self._cur_reference.comment += ' ' + content else: self._cur_reference.comment = content
try: self.data.annotations['comment'] += "\n" + "\n".join(content) except KeyError: self.data.annotations['comment'] = "\n".join(content)
"""Get ready for the feature table when we reach the FEATURE line. """ self.start_feature_table()
"""Indicate we've got to the start of the feature table. """ # make sure we've added on our last reference object if self._cur_reference is not None: self.data.annotations['references'].append(self._cur_reference) self._cur_reference = None
# start a new feature self._cur_feature = SeqFeature.SeqFeature() self._cur_feature.type = content self.data.features.append(self._cur_feature)
"""Parse out location information from the location string.
This uses simple Python code with some regular expressions to do the parsing, and then translates the results into appropriate objects. """ # clean up newlines and other whitespace inside the location before # parsing - locations should have no whitespace whatsoever location_line = self._clean_location(content)
# Older records have junk like replace(266,"c") in the # location line. Newer records just replace this with # the number 266 and have the information in a more reasonable # place. So we'll just grab out the number and feed this to the # parser. We shouldn't really be losing any info this way. if 'replace' in location_line: comma_pos = location_line.find(',') location_line = location_line[8:comma_pos]
cur_feature = self._cur_feature
#Handle top level complement here for speed if location_line.startswith("complement("): assert location_line.endswith(")") location_line = location_line[11:-1] strand = -1 elif "PROTEIN" in self._seq_type.upper(): strand = None else: #Assume nucleotide otherwise feature strand for #GenBank files with bad LOCUS lines set to None strand = 1
#Special case handling of the most common cases for speed if _re_simple_location.match(location_line): #e.g. "123..456" s, e = location_line.split("..") cur_feature.location = SeqFeature.FeatureLocation(int(s)-1, int(e), strand) return
if _solo_bond.search(location_line): #e.g. bond(196) #e.g. join(bond(284),bond(305),bond(309),bond(305)) import warnings from Bio import BiopythonParserWarning warnings.warn("Dropping bond qualifier in feature location", BiopythonParserWarning) #There ought to be a better way to do this... for x in _solo_bond.finditer(location_line): x = x.group() location_line = location_line.replace(x, x[5:-1])
if _re_simple_compound.match(location_line): #e.g. join(<123..456,480..>500) i = location_line.find("(") #cur_feature.location_operator = location_line[:i] #we can split on the comma because these are simple locations sub_features = cur_feature.sub_features for part in location_line[i+1:-1].split(","): s, e = part.split("..") f = SeqFeature.SeqFeature(SeqFeature.FeatureLocation(int(s)-1, int(e), strand), location_operator=cur_feature.location_operator, type=cur_feature.type) sub_features.append(f) #s = cur_feature.sub_features[0].location.start #e = cur_feature.sub_features[-1].location.end #cur_feature.location = SeqFeature.FeatureLocation(s,e, strand) #TODO - Remove use of sub_features if strand == -1: cur_feature.location = SeqFeature.CompoundLocation([f.location for f in sub_features[::-1]], operator=location_line[:i]) else: cur_feature.location = SeqFeature.CompoundLocation([f.location for f in sub_features], operator=location_line[:i]) return
#Handle the general case with more complex regular expressions if _re_complex_location.match(location_line): #e.g. "AL121804.2:41..610" if ":" in location_line: location_ref, location_line = location_line.split(":") cur_feature.location = _loc(location_line, self._expected_size, strand) cur_feature.location.ref = location_ref else: cur_feature.location = _loc(location_line, self._expected_size, strand) return
if _re_complex_compound.match(location_line): i = location_line.find("(") #cur_feature.location_operator = location_line[:i] #Can't split on the comma because of positions like one-of(1,2,3) sub_features = cur_feature.sub_features for part in _split_compound_loc(location_line[i+1:-1]): if part.startswith("complement("): assert part[-1]==")" part = part[11:-1] assert strand != -1, "Double complement?" part_strand = -1 else: part_strand = strand if ":" in part: ref, part = part.split(":") else: ref = None try: loc = _loc(part, self._expected_size, part_strand) except ValueError as err: print(location_line) print(part) raise err f = SeqFeature.SeqFeature(location=loc, ref=ref, location_operator=cur_feature.location_operator, type=cur_feature.type) sub_features.append(f) # Historically a join on the reverse strand has been represented # in Biopython with both the parent SeqFeature and its children # (the exons for a CDS) all given a strand of -1. Likewise, for # a join feature on the forward strand they all have strand +1. # However, we must also consider evil mixed strand examples like # this, join(complement(69611..69724),139856..140087,140625..140650) # # TODO - Remove use of sub_features strands = set(sf.strand for sf in sub_features) if len(strands)==1: strand = sub_features[0].strand else: strand = None # i.e. mixed strands if strand == -1: #Reverse the backwards order used in GenBank files cur_feature.location = SeqFeature.CompoundLocation([f.location for f in sub_features[::-1]], operator=location_line[:i]) else: cur_feature.location = SeqFeature.CompoundLocation([f.location for f in sub_features], operator=location_line[:i]) return #Not recognised if "order" in location_line and "join" in location_line: #See Bug 3197 msg = 'Combinations of "join" and "order" within the same ' + \ 'location (nested operators) are illegal:\n' + location_line raise LocationParserError(msg) #This used to be an error.... cur_feature.location = None import warnings from Bio import BiopythonParserWarning warnings.warn(BiopythonParserWarning("Couldn't parse feature location: %r" % (location_line)))
"""When we get a qualifier key and its value.
Can receive None, since you can have valueless keys such as /pseudo """ # Hack to try to preserve historical behaviour of /pseudo etc if value is None: # if the key doesn't exist yet, add an empty string if key not in self._cur_feature.qualifiers: self._cur_feature.qualifiers[key] = [""] return # otherwise just skip this key return
value = value.replace('"', '') if self._feature_cleaner is not None: value = self._feature_cleaner.clean_value(key, value)
# if the qualifier name exists, append the value if key in self._cur_feature.qualifiers: self._cur_feature.qualifiers[key].append(value) # otherwise start a new list of the key with its values else: self._cur_feature.qualifiers[key] = [value]
"""Use feature_qualifier instead (OBSOLETE).""" raise NotImplementedError("Use the feature_qualifier method instead.")
"""Use feature_qualifier instead (OBSOLETE).""" raise NotImplementedError("Use the feature_qualifier method instead.")
"""Deal with CONTIG information.""" #Historically this was stored as a SeqFeature object, but it was #stored under record.annotations["contig"] and not under #record.features with the other SeqFeature objects. # #The CONTIG location line can include additional tokens like #Gap(), Gap(100) or Gap(unk100) which are not used in the feature #location lines, so storing it using SeqFeature based location #objects is difficult. # #We now store this a string, which means for BioSQL we are now in #much better agreement with how BioPerl records the CONTIG line #in the database. # #NOTE - This code assumes the scanner will return all the CONTIG #lines already combined into one long string! self.data.annotations["contig"] = content
pass
pass
pass
"""Add up sequence information as we get it.
To try and make things speedier, this puts all of the strings into a list of strings, and then uses string.join later to put them together. Supposedly, this is a big time savings """ assert ' ' not in content self._seq_data.append(content.upper())
"""Clean up when we've finished the record. """ from Bio import Alphabet from Bio.Alphabet import IUPAC from Bio.Seq import Seq, UnknownSeq
#Try and append the version number to the accession for the full id if not self.data.id: assert 'accessions' not in self.data.annotations, \ self.data.annotations['accessions'] self.data.id = self.data.name # Good fall back? elif self.data.id.count('.') == 0: try: self.data.id+='.%i' % self.data.annotations['sequence_version'] except KeyError: pass
# add the sequence information # first, determine the alphabet # we default to an generic alphabet if we don't have a # seq type or have strange sequence information. seq_alphabet = Alphabet.generic_alphabet
# now set the sequence sequence = "".join(self._seq_data)
if self._expected_size is not None \ and len(sequence) != 0 \ and self._expected_size != len(sequence): import warnings from Bio import BiopythonParserWarning warnings.warn("Expected sequence length %i, found %i (%s)." % (self._expected_size, len(sequence), self.data.id), BiopythonParserWarning)
if self._seq_type: # mRNA is really also DNA, since it is actually cDNA if 'DNA' in self._seq_type.upper() or 'MRNA' in self._seq_type.upper(): seq_alphabet = IUPAC.ambiguous_dna # are there ever really RNA sequences in GenBank? elif 'RNA' in self._seq_type.upper(): #Even for data which was from RNA, the sequence string #is usually given as DNA (T not U). Bug 2408 if "T" in sequence and "U" not in sequence: seq_alphabet = IUPAC.ambiguous_dna else: seq_alphabet = IUPAC.ambiguous_rna elif 'PROTEIN' in self._seq_type.upper() \ or self._seq_type == "PRT": # PRT is used in EMBL-bank for patents seq_alphabet = IUPAC.protein # or extended protein? # work around ugly GenBank records which have circular or # linear but no indication of sequence type elif self._seq_type in ["circular", "linear", "unspecified"]: pass # we have a bug if we get here else: raise ValueError("Could not determine alphabet for seq_type %s" % self._seq_type)
if not sequence and self.__expected_size: self.data.seq = UnknownSeq(self._expected_size, seq_alphabet) else: self.data.seq = Seq(sequence, seq_alphabet)
"""Create a GenBank Record object from scanner generated information (PRIVATE). """ _BaseGenBankConsumer.__init__(self) from . import Record self.data = Record.Record()
self._seq_data = [] self._cur_reference = None self._cur_feature = None self._cur_qualifier = None
self.data.wgs = content.split('-')
self.data.wgs_scafld.append(content.split('-'))
self.data.locus = content
self.data.size = content
# Be lenient about parsing, but technically lowercase residue types are malformed. if 'dna' in content or 'rna' in content: import warnings from Bio import BiopythonParserWarning warnings.warn("Invalid seq_type (%s): DNA/RNA should be uppercase." % content, BiopythonParserWarning) self.data.residue_type = content
self.data.data_file_division = content
self.data.date = content
self.data.definition = content
for acc in self._split_accessions(content): if acc not in self.data.accession: self.data.accession.append(acc)
self.data.nid = content
self.data.pid = content
self.data.version = content
self.data.db_source = content.rstrip()
self.data.gi = content
self.data.keywords = self._split_keywords(content)
self.data.projects.extend(p for p in content.split() if p)
self.data.dblinks.append(content)
self.data.segment = content
self.data.source = content
self.data.organism = content
self.data.taxonomy = self._split_taxonomy(content)
"""Grab the reference number and signal the start of a new reference. """ # check if we have a reference to add if self._cur_reference is not None: self.data.references.append(self._cur_reference)
from . import Record self._cur_reference = Record.Reference() self._cur_reference.number = content
self._cur_reference.bases = content
self._cur_reference.authors = content
self._cur_reference.consrtm = content
if self._cur_reference is None: import warnings from Bio import BiopythonParserWarning warnings.warn("GenBank TITLE line without REFERENCE line.", BiopythonParserWarning) return self._cur_reference.title = content
self._cur_reference.journal = content
self._cur_reference.medline_id = content
self._cur_reference.pubmed_id = content
self._cur_reference.remark = content
self.data.comment += "\n".join(content)
"""Data for the PRIMARY line""" self.data.primary.append(content)
pass
"""Get ready for the feature table when we reach the FEATURE line. """ self.start_feature_table()
"""Signal the start of the feature table. """ # we need to add on the last reference if self._cur_reference is not None: self.data.references.append(self._cur_reference)
"""Grab the key of the feature and signal the start of a new feature. """ # first add on feature information if we've got any self._add_feature()
from . import Record self._cur_feature = Record.Feature() self._cur_feature.key = content
"""Utility function to add a feature to the Record.
This does all of the appropriate checking to make sure we haven't left any info behind, and that we are only adding info if it exists. """ if self._cur_feature is not None: # if we have a left over qualifier, add it to the qualifiers # on the current feature if self._cur_qualifier is not None: self._cur_feature.qualifiers.append(self._cur_qualifier)
self._cur_qualifier = None self.data.features.append(self._cur_feature)
self._cur_feature.location = self._clean_location(content)
self.feature_qualifier_name([key]) if value is not None: self.feature_qualifier_description(value)
"""Deal with qualifier names
We receive a list of keys, since you can have valueless keys such as /pseudo which would be passed in with the next key (since no other tags separate them in the file) """ from . import Record for content in content_list: # the record parser keeps the /s -- add them if we don't have 'em if not content.startswith("/"): content = "/%s" % content # add on a qualifier if we've got one if self._cur_qualifier is not None: self._cur_feature.qualifiers.append(self._cur_qualifier)
self._cur_qualifier = Record.Qualifier() self._cur_qualifier.key = content
# if we have info then the qualifier key should have a ='s if '=' not in self._cur_qualifier.key: self._cur_qualifier.key = "%s=" % self._cur_qualifier.key cur_content = self._remove_newlines(content) # remove all spaces from the value if it is a type where spaces # are not important for remove_space_key in self.__class__.remove_space_keys: if remove_space_key in self._cur_qualifier.key: cur_content = self._remove_spaces(cur_content) self._cur_qualifier.value = self._normalize_spaces(cur_content)
self.data.base_counts = content
self.data.origin = content
"""Signal that we have contig information to add to the record. """ self.data.contig = self._clean_location(content)
"""Add sequence information to a list of sequence strings.
This removes spaces in the data and uppercases the sequence, and then adds it to a list of sequences. Later on we'll join this list together to make the final sequence. This is faster than adding on the new string every time. """ assert ' ' not in content self._seq_data.append(content.upper())
"""Signal the end of the record and do any necessary clean-up. """ # add together all of the sequence parts to create the # final sequence string self.data.sequence = "".join(self._seq_data) # add on the last feature self._add_feature()
"""Iterate over GenBank formatted entries as Record objects.
>>> from Bio import GenBank >>> with open("GenBank/NC_000932.gb") as handle: ... for record in GenBank.parse(handle): ... print(record.accession) ['NC_000932']
To get SeqRecord objects use Bio.SeqIO.parse(..., format="gb") instead. """ return iter(Iterator(handle, RecordParser()))
"""Read a handle containing a single GenBank entry as a Record object.
>>> from Bio import GenBank >>> with open("GenBank/NC_000932.gb") as handle: ... record = GenBank.read(handle) ... print(record.accession) ['NC_000932']
To get a SeqRecord object use Bio.SeqIO.read(..., format="gb") instead. """ iterator = parse(handle) try: first = next(iterator) except StopIteration: first = None if first is None: raise ValueError("No records found in handle") try: second = next(iterator) except StopIteration: second = None if second is not None: raise ValueError("More than one record found in handle") return first
"""Run the Bio.GenBank module's doctests.""" import doctest import os if os.path.isdir(os.path.join("..", "..", "Tests")): print("Running doctests...") cur_dir = os.path.abspath(os.curdir) os.chdir(os.path.join("..", "..", "Tests")) doctest.testmod() os.chdir(cur_dir) del cur_dir print("Done") elif os.path.isdir(os.path.join("Tests")): print("Running doctests...") cur_dir = os.path.abspath(os.curdir) os.chdir(os.path.join("Tests")) doctest.testmod() os.chdir(cur_dir) del cur_dir print("Done")
_test() |