spaCy/spacy/gold.pyx
2017-04-16 13:00:37 -05:00

387 lines
13 KiB
Cython

# cython: profile=True
# coding: utf8
from __future__ import unicode_literals, print_function
import io
import re
import ujson
from .syntax import nonproj
from .util import ensure_path
def tags_to_entities(tags):
entities = []
start = None
for i, tag in enumerate(tags):
if tag is None:
continue
if tag.startswith('O'):
# TODO: We shouldn't be getting these malformed inputs. Fix this.
if start is not None:
start = None
continue
elif tag == '-':
continue
elif tag.startswith('I'):
assert start is not None, tags[:i]
continue
if tag.startswith('U'):
entities.append((tag[2:], i, i))
elif tag.startswith('B'):
start = i
elif tag.startswith('L'):
entities.append((tag[2:], start, i))
start = None
else:
raise Exception(tag)
return entities
def merge_sents(sents):
m_deps = [[], [], [], [], [], []]
m_brackets = []
i = 0
for (ids, words, tags, heads, labels, ner), brackets in sents:
m_deps[0].extend(id_ + i for id_ in ids)
m_deps[1].extend(words)
m_deps[2].extend(tags)
m_deps[3].extend(head + i for head in heads)
m_deps[4].extend(labels)
m_deps[5].extend(ner)
m_brackets.extend((b['first'] + i, b['last'] + i, b['label']) for b in brackets)
i += len(ids)
return [(m_deps, m_brackets)]
def align(cand_words, gold_words):
cost, edit_path = _min_edit_path(cand_words, gold_words)
alignment = []
i_of_gold = 0
for move in edit_path:
if move == 'M':
alignment.append(i_of_gold)
i_of_gold += 1
elif move == 'S':
alignment.append(None)
i_of_gold += 1
elif move == 'D':
alignment.append(None)
elif move == 'I':
i_of_gold += 1
else:
raise Exception(move)
return alignment
punct_re = re.compile(r'\W')
def _min_edit_path(cand_words, gold_words):
cdef:
Pool mem
int i, j, n_cand, n_gold
int* curr_costs
int* prev_costs
# TODO: Fix this --- just do it properly, make the full edit matrix and
# then walk back over it...
# Preprocess inputs
cand_words = [punct_re.sub('', w) for w in cand_words]
gold_words = [punct_re.sub('', w) for w in gold_words]
if cand_words == gold_words:
return 0, ''.join(['M' for _ in gold_words])
mem = Pool()
n_cand = len(cand_words)
n_gold = len(gold_words)
# Levenshtein distance, except we need the history, and we may want different
# costs.
# Mark operations with a string, and score the history using _edit_cost.
previous_row = []
prev_costs = <int*>mem.alloc(n_gold + 1, sizeof(int))
curr_costs = <int*>mem.alloc(n_gold + 1, sizeof(int))
for i in range(n_gold + 1):
cell = ''
for j in range(i):
cell += 'I'
previous_row.append('I' * i)
prev_costs[i] = i
for i, cand in enumerate(cand_words):
current_row = ['D' * (i + 1)]
curr_costs[0] = i+1
for j, gold in enumerate(gold_words):
if gold.lower() == cand.lower():
s_cost = prev_costs[j]
i_cost = curr_costs[j] + 1
d_cost = prev_costs[j + 1] + 1
else:
s_cost = prev_costs[j] + 1
i_cost = curr_costs[j] + 1
d_cost = prev_costs[j + 1] + (1 if cand else 0)
if s_cost <= i_cost and s_cost <= d_cost:
best_cost = s_cost
best_hist = previous_row[j] + ('M' if gold == cand else 'S')
elif i_cost <= s_cost and i_cost <= d_cost:
best_cost = i_cost
best_hist = current_row[j] + 'I'
else:
best_cost = d_cost
best_hist = previous_row[j + 1] + 'D'
current_row.append(best_hist)
curr_costs[j+1] = best_cost
previous_row = current_row
for j in range(len(gold_words) + 1):
prev_costs[j] = curr_costs[j]
curr_costs[j] = 0
return prev_costs[n_gold], previous_row[-1]
def read_json_file(loc, docs_filter=None):
loc = ensure_path(loc)
if loc.is_dir():
for filename in loc.iterdir():
yield from read_json_file(loc / filename)
else:
with loc.open('r', encoding='utf8') as file_:
docs = ujson.load(file_)
for doc in docs:
if docs_filter is not None and not docs_filter(doc):
continue
paragraphs = []
for paragraph in doc['paragraphs']:
sents = []
for sent in paragraph['sentences']:
words = []
ids = []
tags = []
heads = []
labels = []
ner = []
for i, token in enumerate(sent['tokens']):
words.append(token['orth'])
ids.append(i)
tags.append(token.get('tag','-'))
heads.append(token.get('head',0) + i)
labels.append(token.get('dep',''))
# Ensure ROOT label is case-insensitive
if labels[-1].lower() == 'root':
labels[-1] = 'ROOT'
ner.append(token.get('ner', '-'))
sents.append((
(ids, words, tags, heads, labels, ner),
sent.get('brackets', [])))
if sents:
yield (paragraph.get('raw', None), sents)
def _iob_to_biluo(tags):
out = []
curr_label = None
tags = list(tags)
while tags:
out.extend(_consume_os(tags))
out.extend(_consume_ent(tags))
return out
def _consume_os(tags):
while tags and tags[0] == 'O':
yield tags.pop(0)
def _consume_ent(tags):
if not tags:
return []
target = tags.pop(0).replace('B', 'I')
length = 1
while tags and tags[0] == target:
length += 1
tags.pop(0)
label = target[2:]
if length == 1:
return ['U-' + label]
else:
start = 'B-' + label
end = 'L-' + label
middle = ['I-%s' % label for _ in range(1, length - 1)]
return [start] + middle + [end]
cdef class GoldParse:
"""Collection for training annotations."""
@classmethod
def from_annot_tuples(cls, doc, annot_tuples, make_projective=False):
_, words, tags, heads, deps, entities = annot_tuples
return cls(doc, words=words, tags=tags, heads=heads, deps=deps, entities=entities,
make_projective=make_projective)
def __init__(self, doc, annot_tuples=None, words=None, tags=None, heads=None,
deps=None, entities=None, make_projective=False):
"""
Create a GoldParse.
Arguments:
doc (Doc):
The document the annotations refer to.
words:
A sequence of unicode word strings.
tags:
A sequence of strings, representing tag annotations.
heads:
A sequence of integers, representing syntactic head offsets.
deps:
A sequence of strings, representing the syntactic relation types.
entities:
A sequence of named entity annotations, either as BILUO tag strings,
or as (start_char, end_char, label) tuples, representing the entity
positions.
Returns (GoldParse): The newly constructed object.
"""
if words is None:
words = [token.text for token in doc]
if tags is None:
tags = [None for _ in doc]
if heads is None:
heads = [token.i for token in doc]
if deps is None:
deps = [None for _ in doc]
if entities is None:
entities = ['-' for _ in doc]
elif len(entities) == 0:
entities = ['O' for _ in doc]
elif not isinstance(entities[0], basestring):
# Assume we have entities specified by character offset.
entities = biluo_tags_from_offsets(doc, entities)
self.mem = Pool()
self.loss = 0
self.length = len(doc)
# These are filled by the tagger/parser/entity recogniser
self.c.tags = <int*>self.mem.alloc(len(doc), sizeof(int))
self.c.heads = <int*>self.mem.alloc(len(doc), sizeof(int))
self.c.labels = <int*>self.mem.alloc(len(doc), sizeof(int))
self.c.ner = <Transition*>self.mem.alloc(len(doc), sizeof(Transition))
self.words = [None] * len(doc)
self.tags = [None] * len(doc)
self.heads = [None] * len(doc)
self.labels = [None] * len(doc)
self.ner = [None] * len(doc)
self.cand_to_gold = align([t.orth_ for t in doc], words)
self.gold_to_cand = align(words, [t.orth_ for t in doc])
annot_tuples = (range(len(words)), words, tags, heads, deps, entities)
self.orig_annot = list(zip(*annot_tuples))
for i, gold_i in enumerate(self.cand_to_gold):
if doc[i].text.isspace():
self.words[i] = doc[i].text
self.tags[i] = 'SP'
self.heads[i] = None
self.labels[i] = None
self.ner[i] = 'O'
if gold_i is None:
pass
else:
self.words[i] = words[gold_i]
self.tags[i] = tags[gold_i]
self.heads[i] = self.gold_to_cand[heads[gold_i]]
self.labels[i] = deps[gold_i]
self.ner[i] = entities[gold_i]
cycle = nonproj.contains_cycle(self.heads)
if cycle != None:
raise Exception("Cycle found: %s" % cycle)
if make_projective:
proj_heads,_ = nonproj.PseudoProjectivity.projectivize(self.heads, self.labels)
self.heads = proj_heads
def __len__(self):
"""
Get the number of gold-standard tokens.
Returns (int): The number of gold-standard tokens.
"""
return self.length
@property
def is_projective(self):
"""
Whether the provided syntactic annotations form a projective dependency
tree.
"""
return not nonproj.is_nonproj_tree(self.heads)
def biluo_tags_from_offsets(doc, entities):
"""
Encode labelled spans into per-token tags, using the Begin/In/Last/Unit/Out
scheme (biluo).
Arguments:
doc (Doc):
The document that the entity offsets refer to. The output tags will
refer to the token boundaries within the document.
entities (sequence):
A sequence of (start, end, label) triples. start and end should be
character-offset integers denoting the slice into the original string.
Returns:
tags (list):
A list of unicode strings, describing the tags. Each tag string will
be of the form either "", "O" or "{action}-{label}", where action is one
of "B", "I", "L", "U". The string "-" is used where the entity
offsets don't align with the tokenization in the Doc object. The
training algorithm will view these as missing values. "O" denotes
a non-entity token. "B" denotes the beginning of a multi-token entity,
"I" the inside of an entity of three or more tokens, and "L" the end
of an entity of two or more tokens. "U" denotes a single-token entity.
Example:
text = 'I like London.'
entities = [(len('I like '), len('I like London'), 'LOC')]
doc = nlp.tokenizer(text)
tags = biluo_tags_from_offsets(doc, entities)
assert tags == ['O', 'O', 'U-LOC', 'O']
"""
starts = {token.idx: token.i for token in doc}
ends = {token.idx+len(token): token.i for token in doc}
biluo = ['-' for _ in doc]
# Handle entity cases
for start_char, end_char, label in entities:
start_token = starts.get(start_char)
end_token = ends.get(end_char)
# Only interested if the tokenization is correct
if start_token is not None and end_token is not None:
if start_token == end_token:
biluo[start_token] = 'U-%s' % label
else:
biluo[start_token] = 'B-%s' % label
for i in range(start_token+1, end_token):
biluo[i] = 'I-%s' % label
biluo[end_token] = 'L-%s' % label
# Now distinguish the O cases from ones where we miss the tokenization
entity_chars = set()
for start_char, end_char, label in entities:
for i in range(start_char, end_char):
entity_chars.add(i)
for token in doc:
for i in range(token.idx, token.idx+len(token)):
if i in entity_chars:
break
else:
biluo[token.i] = 'O'
return biluo
def is_punct_label(label):
return label == 'P' or label.lower() == 'punct'