def _set_qresult_hits(qresult, hit_rows=()):
"""Helper function for appending Hits without alignments into QueryResults."""
for hit_row in hit_rows:
hit_id, remainder = hit_row.split(' ', 1)
# TODO: parse hit and hsp properties properly; by dealing with:
# - any character in the description (brackets, spaces, etc.)
# - possible [f] or [r] presence (for frame info)
# - possible presence of E2() column
# - possible incomplete hit_id due to column length limit
# The current method only looks at the Hit ID, none of the things above
if hit_id not in qresult:
frag = HSPFragment(hit_id, qresult.id)
hsp = HSP([frag])
hit = Hit([hsp])
qresult.append(hit)
return qresult
def _parse_hit(self, query_id):
while True:
self.line = self.handle.readline()
if self.line.startswith('>>'):
break
state = _STATE_NONE
strand = None
hsp_list = []
while True:
peekline = self.handle.peekline()
# yield hit if we've reached the start of a new query or
# the end of the search
if peekline.strip() in [">>><<<", ">>>///"] or \
(not peekline.startswith('>>>') and '>>>' in peekline):
# append last parsed_hsp['hit']['seq'] line
if state == _STATE_HIT_BLOCK:
parsed_hsp['hit']['seq'] += self.line.strip()
elif state == _STATE_CONS_BLOCK:
hsp.aln_annotation['similarity'] += \
self.line.strip('\r\n')
# process HSP alignment and coordinates
_set_hsp_seqs(hsp, parsed_hsp, self._preamble['program'])
hit = Hit(hsp_list)
hit.description = hit_desc
hit.seq_len = seq_len
yield hit, strand
hsp_list = []
break
# yield hit and create a new one if we're still in the same query
elif self.line.startswith('>>'):
# try yielding, if we have hsps
if hsp_list:
_set_hsp_seqs(hsp, parsed_hsp, self._preamble['program'])
hit = Hit(hsp_list)
hit.description = hit_desc
hit.seq_len = seq_len
yield hit, strand
hsp_list = []
# try to get the hit id and desc, and handle cases without descs
try:
hit_id, hit_desc = self.line[2:].strip().split(' ', 1)
except ValueError:
hit_id = self.line[2:].strip().split(' ', 1)[0]
hit_desc = ''
# create the HSP object for Hit
frag = HSPFragment(hit_id, query_id)
hsp = HSP([frag])
hsp_list.append(hsp)
# set or reset the state to none
state = _STATE_NONE
parsed_hsp = {'query': {}, 'hit': {}}
# create and append a new HSP if line starts with '>--'
elif self.line.startswith('>--'):
# set seq attributes of previous hsp
_set_hsp_seqs(hsp, parsed_hsp, self._preamble['program'])
# and create a new one
frag = HSPFragment(hit_id, query_id)
hsp = HSP([frag])
hsp_list.append(hsp)
# set the state ~ none yet
state = _STATE_NONE
parsed_hsp = {'query': {}, 'hit': {}}
# this is either query or hit data in the HSP, depending on the state
elif self.line.startswith('>'):
if state == _STATE_NONE:
# make sure it's the correct query
assert query_id.startswith(self.line[1:].split(' ')[0]), \
"%r vs %r" % (query_id, self.line)
state = _STATE_QUERY_BLOCK
parsed_hsp['query']['seq'] = ''
elif state == _STATE_QUERY_BLOCK:
# make sure it's the correct hit
assert hit_id.startswith(self.line[1:].split(' ')[0])
state = _STATE_HIT_BLOCK
parsed_hsp['hit']['seq'] = ''
# check for conservation block
elif self.line.startswith('; al_cons'):
state = _STATE_CONS_BLOCK
hsp.fragment.aln_annotation['similarity'] = ''
elif self.line.startswith(';'):
# Fasta outputs do not make a clear distinction between Hit
# and HSPs, so we check the attribute names to determine
# whether it belongs to a Hit or HSP
regx = re.search(_RE_ATTR, self.line.strip())
name = regx.group(1)
value = regx.group(2)
# for values before the '>...' query block
if state == _STATE_NONE:
if name in _HSP_ATTR_MAP:
attr_name, caster = _HSP_ATTR_MAP[name]
if caster is not str:
value = caster(value)
if name in ['_ident', '_sim']:
value *= 100
setattr(hsp, attr_name, value)
# otherwise, pool the values for processing later
elif state == _STATE_QUERY_BLOCK:
parsed_hsp['query'][name] = value
elif state == _STATE_HIT_BLOCK:
if name == '_len':
seq_len = int(value)
else:
parsed_hsp['hit'][name] = value
# for values in the hit block
else:
raise ValueError("Unexpected line: %r" % self.line)
# otherwise, it must be lines containing the sequences
else:
assert '>' not in self.line
# if we're in hit, parse into hsp.hit
if state == _STATE_HIT_BLOCK:
parsed_hsp['hit']['seq'] += self.line.strip()
elif state == _STATE_QUERY_BLOCK:
parsed_hsp['query']['seq'] += self.line.strip()
elif state == _STATE_CONS_BLOCK:
hsp.fragment.aln_annotation['similarity'] += \
self.line.strip('\r\n')
# we should not get here!
else:
raise ValueError("Unexpected line: %r" % self.line)
self.line = self.handle.readline()
def _parse_qresult(self):
"""Generator function that returns QueryResult objects."""
# state values, determines what to do for each line
state_EOF = 0
state_QRES_NEW = 1
state_QRES_SAME = 3
# initial value dummies
qres_state = None
file_state = None
prev_qid = None
cur, prev = None, None
# container for Hit objects, used to create QueryResult
hit_list = []
while True:
# store previous line's parsed values for all lines after the first
if cur is not None:
prev = cur
prev_qid = cur_qid
# only parse the result row if it's not EOF
# NOTE: we are not parsing the extra '#' lines appended to the end
# of hmmer31b1 tabular results since storing them in qresult
# objects means we can not do a single-pass parsing
if self.line and not self.line.startswith('#'):
cur = self._parse_row()
cur_qid = cur['qresult']['id']
else:
file_state = state_EOF
# mock value for cur_qid, since we have nothing to parse
cur_qid = None
if prev_qid != cur_qid:
qres_state = state_QRES_NEW
else:
qres_state = state_QRES_SAME
if prev is not None:
# since domain tab formats only have 1 Hit per line
# we always create HSPFragment, HSP, and Hit per line
prev_hid = prev['hit']['id']
# create fragment and HSP and set their attributes
frag = HSPFragment(prev_hid, prev_qid)
for attr, value in prev['frag'].items():
setattr(frag, attr, value)
hsp = HSP([frag])
for attr, value in prev['hsp'].items():
setattr(hsp, attr, value)
# create Hit and set its attributes
hit = Hit([hsp])
for attr, value in prev['hit'].items():
setattr(hit, attr, value)
hit_list.append(hit)
# create qresult and yield if we're at a new qresult or at EOF
if qres_state == state_QRES_NEW or file_state == state_EOF:
qresult = QueryResult(hit_list, prev_qid)
for attr, value in prev['qresult'].items():
setattr(qresult, attr, value)
yield qresult
# if we're at EOF, break
if file_state == state_EOF:
break
hit_list = []
self.line = self.handle.readline()
def _create_hits(self, hit_attrs, qid, qdesc):
"""Parses a HMMER3 hsp block, beginning with the hsp table."""
# read through until the beginning of the hsp block
self._read_until(lambda line: line.startswith('Internal pipeline') or
line.startswith('>>'))
# start parsing the hsp block
hit_list = []
while True:
if self.line.startswith('Internal pipeline'):
# by this time we should've emptied the hit attr list
assert len(hit_attrs) == 0
return hit_list
assert self.line.startswith('>>')
hid, hdesc = self.line[len('>> '):].split(' ', 1)
hdesc = hdesc.strip()
# read through the hsp table header and move one more line
self._read_until(lambda line:
line.startswith(' --- ------ ----- --------') or
line.startswith(' [No individual domains'))
self.line = read_forward(self.handle)
# parse the hsp table for the current hit
hsp_list = []
while True:
# break out of hsp parsing if there are no hits, it's the last hsp
# or it's the start of a new hit
if self.line.startswith(' [No targets detected that satisfy') or \
self.line.startswith(' [No individual domains') or \
self.line.startswith('Internal pipeline statistics summary:') or \
self.line.startswith(' Alignments for each domain:') or \
self.line.startswith('>>'):
hit_attr = hit_attrs.pop(0)
hit = Hit(hsp_list)
for attr, value in hit_attr.items():
if attr == "description":
cur_val = getattr(hit, attr)
if cur_val and value and cur_val.startswith(value):
continue
setattr(hit, attr, value)
if not hit:
hit.query_description = qdesc
hit_list.append(hit)
break
parsed = [x for x in self.line.strip().split(' ') if x]
assert len(parsed) == 16
# parsed column order:
# index, is_included, bitscore, bias, evalue_cond, evalue
# hmmfrom, hmmto, query_ends, hit_ends, alifrom, alito,
# envfrom, envto, acc_avg
frag = HSPFragment(hid, qid)
# set query and hit descriptions if they are defined / nonempty string
if qdesc:
frag.query_description = qdesc
if hdesc:
frag.hit_description = hdesc
# HMMER3 alphabets are always protein alphabets
frag.alphabet = generic_protein
# depending on whether the program is hmmsearch, hmmscan, or phmmer
# {hmm,ali}{from,to} can either be hit_{from,to} or query_{from,to}
# for hmmscan, hit is the hmm profile, query is the sequence
if self._meta.get('program') == 'hmmscan':
# adjust 'from' and 'to' coordinates to 0-based ones
frag.hit_start = int(parsed[6]) - 1
frag.hit_end = int(parsed[7])
frag.query_start = int(parsed[9]) - 1
frag.query_end = int(parsed[10])
elif self._meta.get('program') in ['hmmsearch', 'phmmer']:
# adjust 'from' and 'to' coordinates to 0-based ones
frag.hit_start = int(parsed[9]) - 1
frag.hit_end = int(parsed[10])
frag.query_start = int(parsed[6]) - 1
frag.query_end = int(parsed[7])
# strand is always 0, since HMMER now only handles protein
frag.hit_strand = frag.query_strand = 0
hsp = HSP([frag])
hsp.domain_index = int(parsed[0])
hsp.is_included = parsed[1] == '!'
hsp.bitscore = float(parsed[2])
hsp.bias = float(parsed[3])
hsp.evalue_cond = float(parsed[4])
hsp.evalue = float(parsed[5])
if self._meta.get('program') == 'hmmscan':
# adjust 'from' and 'to' coordinates to 0-based ones
hsp.hit_endtype = parsed[8]
hsp.query_endtype = parsed[11]
elif self._meta.get('program') in ['hmmsearch', 'phmmer']:
# adjust 'from' and 'to' coordinates to 0-based ones
hsp.hit_endtype = parsed[11]
hsp.query_endtype = parsed[8]
# adjust 'from' and 'to' coordinates to 0-based ones
hsp.env_start = int(parsed[12]) - 1
hsp.env_end = int(parsed[13])
hsp.env_endtype = parsed[14]
hsp.acc_avg = float(parsed[15])
hsp_list.append(hsp)
self.line = read_forward(self.handle)
# parse the hsp alignments
if self.line.startswith(' Alignments for each domain:'):
self._parse_aln_block(hid, hit.hsps)
def parse_hsps(self, hit_placeholders):
"""Parse a HMMER2 hsp block, beginning with the hsp table."""
# HSPs may occur in different order than the hits
# so store Hit objects separately first
unordered_hits = {}
while self.read_next():
if self.line.startswith('Alignments') or \
self.line.startswith('Histogram') or \
self.line == '//':
break
if self.line.startswith('Model') or \
self.line.startswith('Sequence') or \
self.line.startswith('--------'):
continue
id_, domain, seq_f, seq_t, seq_compl, hmm_f, hmm_t, hmm_compl, \
score, evalue = self.line.split()
frag = HSPFragment(id_, self.qresult.id)
frag.alphabet = generic_protein
if self._meta['program'] == 'hmmpfam':
frag.hit_start = int(hmm_f) - 1
frag.hit_end = int(hmm_t)
frag.query_start = int(seq_f) - 1
frag.query_end = int(seq_t)
elif self._meta['program'] == 'hmmsearch':
frag.query_start = int(hmm_f) - 1
frag.query_end = int(hmm_t)
frag.hit_start = int(seq_f) - 1
frag.hit_end = int(seq_t)
hsp = HSP([frag])
hsp.evalue = float(evalue)
hsp.bitscore = float(score)
hsp.domain_index = int(domain.split('/')[0])
if self._meta['program'] == 'hmmpfam':
hsp.hit_endtype = hmm_compl
hsp.query_endtype = seq_compl
elif self._meta['program'] == 'hmmsearch':
hsp.query_endtype = hmm_compl
hsp.hit_endtype = seq_compl
if id_ not in unordered_hits:
placeholder = [p for p in hit_placeholders if p.id_ == id_][0]
hit = placeholder.createHit([hsp])
unordered_hits[id_] = hit
else:
hit = unordered_hits[id_]
hsp.hit_description = hit.description
hit.append(hsp)
# The placeholder list is in the correct order, so use that order for
# the Hit objects in the qresult
for p in hit_placeholders:
self.qresult.append(unordered_hits[p.id_])
def _create_hsp(hid, qid, psl):
# protein flag
is_protein = _is_protein(psl)
# strand
# if query is protein, strand is 0
if is_protein:
qstrand = 0
else:
qstrand = 1 if psl['strand'][0] == '+' else -1
# try to get hit strand, if it exists
try:
hstrand = 1 if psl['strand'][1] == '+' else -1
except IndexError:
hstrand = 1 # hit strand defaults to plus
# query block starts
qstarts = _reorient_starts(psl['qstarts'],
psl['blocksizes'], psl['qsize'], qstrand)
# hit block starts
if len(psl['strand']) == 2:
hstarts = _reorient_starts(psl['tstarts'],
psl['blocksizes'], psl['tsize'], hstrand)
else:
hstarts = psl['tstarts']
# set query and hit coords
# this assumes each block has no gaps (which seems to be the case)
assert len(qstarts) == len(hstarts) == len(psl['blocksizes'])
query_range_all = list(zip(qstarts, [x + y for x, y in
zip(qstarts, psl['blocksizes'])]))
hit_range_all = list(zip(hstarts, [x + y for x, y in
zip(hstarts, psl['blocksizes'])]))
# check length of sequences and coordinates, all must match
if 'tseqs' in psl and 'qseqs' in psl:
assert len(psl['tseqs']) == len(psl['qseqs']) == \
len(query_range_all) == len(hit_range_all)
else:
assert len(query_range_all) == len(hit_range_all)
frags = []
# iterating over query_range_all, but hit_range_all works just as well
for idx, qcoords in enumerate(query_range_all):
hseqlist = psl.get('tseqs')
hseq = '' if not hseqlist else hseqlist[idx]
qseqlist = psl.get('qseqs')
qseq = '' if not qseqlist else qseqlist[idx]
frag = HSPFragment(hid, qid, hit=hseq, query=qseq)
# set alphabet
frag.alphabet = generic_dna
# set coordinates
frag.query_start = qcoords[0]
frag.query_end = qcoords[1]
frag.hit_start = hit_range_all[idx][0]
frag.hit_end = hit_range_all[idx][1]
# and strands
frag.query_strand = qstrand
frag.hit_strand = hstrand
frags.append(frag)
# create hsp object
hsp = HSP(frags)
# check if start and end are set correctly
assert hsp.query_start == psl['qstart']
assert hsp.query_end == psl['qend']
assert hsp.hit_start == psl['tstart']
assert hsp.hit_end == psl['tend']
# and check block spans as well
assert hsp.query_span_all == hsp.hit_span_all == psl['blocksizes']
# set its attributes
hsp.match_num = psl['matches']
hsp.mismatch_num = psl['mismatches']
hsp.match_rep_num = psl['repmatches']
hsp.n_num = psl['ncount']
hsp.query_gapopen_num = psl['qnuminsert']
hsp.query_gap_num = psl['qbaseinsert']
hsp.hit_gapopen_num = psl['tnuminsert']
hsp.hit_gap_num = psl['tbaseinsert']
hsp.ident_num = psl['matches'] + psl['repmatches']
hsp.gapopen_num = psl['qnuminsert'] + psl['tnuminsert']
hsp.gap_num = psl['qbaseinsert'] + psl['tbaseinsert']
hsp.query_is_protein = is_protein
hsp.ident_pct = 100.0 - _calc_millibad(psl, is_protein) * 0.1
hsp.score = _calc_score(psl, is_protein)
# helper flag, for writing
hsp._has_hit_strand = len(psl['strand']) == 2
return hsp