import random
from itertools import islice
from pathlib import Path
from typing import Any, Callable, Dict, Iterable, List, Optional, Union
import srsly
from thinc.api import Config, CosineDistance, Model, Optimizer, set_dropout_rate
from thinc.types import Floats2d
from .. import util
from ..errors import Errors
from ..kb import Candidate, KnowledgeBase
from ..language import Language
from ..ml import empty_kb
from ..scorer import Scorer
from ..tokens import Doc, Span
from ..training import Example, validate_examples, validate_get_examples
from ..util import SimpleFrozenList, registry
from ..vocab import Vocab
from .legacy.entity_linker import EntityLinker_v1
from .pipe import deserialize_config
from .trainable_pipe import TrainablePipe
# See #9050
BACKWARD_OVERWRITE = True
default_model_config = """
[model]
@architectures = "spacy.EntityLinker.v2"
[model.tok2vec]
@architectures = "spacy.HashEmbedCNN.v2"
pretrained_vectors = null
width = 96
depth = 2
embed_size = 2000
window_size = 1
maxout_pieces = 3
subword_features = true
"""
DEFAULT_NEL_MODEL = Config().from_str(default_model_config)["model"]
@Language.factory(
"entity_linker",
requires=["doc.ents", "doc.sents", "token.ent_iob", "token.ent_type"],
assigns=["token.ent_kb_id"],
default_config={
"model": DEFAULT_NEL_MODEL,
"labels_discard": [],
"n_sents": 0,
"incl_prior": True,
"incl_context": True,
"entity_vector_length": 64,
"get_candidates": {"@misc": "spacy.CandidateGenerator.v1"},
"get_candidates_batch": {"@misc": "spacy.CandidateBatchGenerator.v1"},
"generate_empty_kb": {"@misc": "spacy.EmptyKB.v2"},
"overwrite": True,
"scorer": {"@scorers": "spacy.entity_linker_scorer.v1"},
"use_gold_ents": True,
"candidates_batch_size": 1,
"threshold": None,
},
default_score_weights={
"nel_micro_f": 1.0,
"nel_micro_r": None,
"nel_micro_p": None,
},
)
def make_entity_linker(
nlp: Language,
name: str,
model: Model,
*,
labels_discard: Iterable[str],
n_sents: int,
incl_prior: bool,
incl_context: bool,
entity_vector_length: int,
get_candidates: Callable[[KnowledgeBase, Span], Iterable[Candidate]],
get_candidates_batch: Callable[
[KnowledgeBase, Iterable[Span]], Iterable[Iterable[Candidate]]
],
generate_empty_kb: Callable[[Vocab, int], KnowledgeBase],
overwrite: bool,
scorer: Optional[Callable],
use_gold_ents: bool,
candidates_batch_size: int,
threshold: Optional[float] = None,
):
"""Construct an EntityLinker component.
model (Model[List[Doc], Floats2d]): A model that learns document vector
representations. Given a batch of Doc objects, it should return a single
array, with one row per item in the batch.
labels_discard (Iterable[str]): NER labels that will automatically get a "NIL" prediction.
n_sents (int): The number of neighbouring sentences to take into account.
incl_prior (bool): Whether or not to include prior probabilities from the KB in the model.
incl_context (bool): Whether or not to include the local context in the model.
entity_vector_length (int): Size of encoding vectors in the KB.
get_candidates (Callable[[KnowledgeBase, Span], Iterable[Candidate]]): Function that
produces a list of candidates, given a certain knowledge base and a textual mention.
get_candidates_batch (
Callable[[KnowledgeBase, Iterable[Span]], Iterable[Iterable[Candidate]]], Iterable[Candidate]]
): Function that produces a list of candidates, given a certain knowledge base and several textual mentions.
generate_empty_kb (Callable[[Vocab, int], KnowledgeBase]): Callable returning empty KnowledgeBase.
scorer (Optional[Callable]): The scoring method.
use_gold_ents (bool): Whether to copy entities from gold docs or not. If false, another
component must provide entity annotations.
candidates_batch_size (int): Size of batches for entity candidate generation.
threshold (Optional[float]): Confidence threshold for entity predictions. If confidence is below the threshold,
prediction is discarded. If None, predictions are not filtered by any threshold.
"""
if not model.attrs.get("include_span_maker", False):
# The only difference in arguments here is that use_gold_ents and threshold aren't available.
return EntityLinker_v1(
nlp.vocab,
model,
name,
labels_discard=labels_discard,
n_sents=n_sents,
incl_prior=incl_prior,
incl_context=incl_context,
entity_vector_length=entity_vector_length,
get_candidates=get_candidates,
overwrite=overwrite,
scorer=scorer,
)
return EntityLinker(
nlp.vocab,
model,
name,
labels_discard=labels_discard,
n_sents=n_sents,
incl_prior=incl_prior,
incl_context=incl_context,
entity_vector_length=entity_vector_length,
get_candidates=get_candidates,
get_candidates_batch=get_candidates_batch,
generate_empty_kb=generate_empty_kb,
overwrite=overwrite,
scorer=scorer,
use_gold_ents=use_gold_ents,
candidates_batch_size=candidates_batch_size,
threshold=threshold,
)
def entity_linker_score(examples, **kwargs):
return Scorer.score_links(examples, negative_labels=[EntityLinker.NIL], **kwargs)
@registry.scorers("spacy.entity_linker_scorer.v1")
def make_entity_linker_scorer():
return entity_linker_score
class EntityLinker(TrainablePipe):
"""Pipeline component for named entity linking.
DOCS: https://spacy.io/api/entitylinker
"""
NIL = "NIL" # string used to refer to a non-existing link
def __init__(
self,
vocab: Vocab,
model: Model,
name: str = "entity_linker",
*,
labels_discard: Iterable[str],
n_sents: int,
incl_prior: bool,
incl_context: bool,
entity_vector_length: int,
get_candidates: Callable[[KnowledgeBase, Span], Iterable[Candidate]],
get_candidates_batch: Callable[
[KnowledgeBase, Iterable[Span]], Iterable[Iterable[Candidate]]
],
generate_empty_kb: Callable[[Vocab, int], KnowledgeBase],
overwrite: bool = BACKWARD_OVERWRITE,
scorer: Optional[Callable] = entity_linker_score,
use_gold_ents: bool,
candidates_batch_size: int,
threshold: Optional[float] = None,
) -> None:
"""Initialize an entity linker.
vocab (Vocab): The shared vocabulary.
model (thinc.api.Model): The Thinc Model powering the pipeline component.
name (str): The component instance name, used to add entries to the
losses during training.
labels_discard (Iterable[str]): NER labels that will automatically get a "NIL" prediction.
n_sents (int): The number of neighbouring sentences to take into account.
incl_prior (bool): Whether or not to include prior probabilities from the KB in the model.
incl_context (bool): Whether or not to include the local context in the model.
entity_vector_length (int): Size of encoding vectors in the KB.
get_candidates (Callable[[KnowledgeBase, Span], Iterable[Candidate]]): Function that
produces a list of candidates, given a certain knowledge base and a textual mention.
get_candidates_batch (
Callable[[KnowledgeBase, Iterable[Span]], Iterable[Iterable[Candidate]]],
Iterable[Candidate]]
): Function that produces a list of candidates, given a certain knowledge base and several textual mentions.
generate_empty_kb (Callable[[Vocab, int], KnowledgeBase]): Callable returning empty KnowledgeBase.
scorer (Optional[Callable]): The scoring method. Defaults to Scorer.score_links.
use_gold_ents (bool): Whether to copy entities from gold docs or not. If false, another
component must provide entity annotations.
candidates_batch_size (int): Size of batches for entity candidate generation.
threshold (Optional[float]): Confidence threshold for entity predictions. If confidence is below the
threshold, prediction is discarded. If None, predictions are not filtered by any threshold.
DOCS: https://spacy.io/api/entitylinker#init
"""
if threshold is not None and not (0 <= threshold <= 1):
raise ValueError(
Errors.E1043.format(
range_start=0,
range_end=1,
value=threshold,
)
)
self.vocab = vocab
self.model = model
self.name = name
self.labels_discard = list(labels_discard)
# how many neighbour sentences to take into account
self.n_sents = n_sents
self.incl_prior = incl_prior
self.incl_context = incl_context
self.get_candidates = get_candidates
self.get_candidates_batch = get_candidates_batch
self.cfg: Dict[str, Any] = {"overwrite": overwrite}
self.distance = CosineDistance(normalize=False)
self.kb = generate_empty_kb(self.vocab, entity_vector_length)
self.scorer = scorer
self.use_gold_ents = use_gold_ents
self.candidates_batch_size = candidates_batch_size
self.threshold = threshold
if candidates_batch_size < 1:
raise ValueError(Errors.E1044)
def set_kb(self, kb_loader: Callable[[Vocab], KnowledgeBase]):
"""Define the KB of this pipe by providing a function that will
create it using this object's vocab."""
if not callable(kb_loader):
raise ValueError(Errors.E885.format(arg_type=type(kb_loader)))
self.kb = kb_loader(self.vocab) # type: ignore
def validate_kb(self) -> None:
# Raise an error if the knowledge base is not initialized.
if self.kb is None:
raise ValueError(Errors.E1018.format(name=self.name))
if hasattr(self.kb, "is_empty") and self.kb.is_empty():
raise ValueError(Errors.E139.format(name=self.name))
def initialize(
self,
get_examples: Callable[[], Iterable[Example]],
*,
nlp: Optional[Language] = None,
kb_loader: Optional[Callable[[Vocab], KnowledgeBase]] = None,
):
"""Initialize the pipe for training, using a representative set
of data examples.
get_examples (Callable[[], Iterable[Example]]): Function that
returns a representative sample of gold-standard Example objects.
nlp (Language): The current nlp object the component is part of.
kb_loader (Callable[[Vocab], KnowledgeBase]): A function that creates a KnowledgeBase from a Vocab
instance. Note that providing this argument will overwrite all data accumulated in the current KB.
Use this only when loading a KB as-such from file.
DOCS: https://spacy.io/api/entitylinker#initialize
"""
validate_get_examples(get_examples, "EntityLinker.initialize")
if kb_loader is not None:
self.set_kb(kb_loader)
self.validate_kb()
nO = self.kb.entity_vector_length
doc_sample = []
vector_sample = []
for eg in islice(get_examples(), 10):
doc = eg.x
if self.use_gold_ents:
ents, _ = eg.get_aligned_ents_and_ner()
doc.ents = ents
doc_sample.append(doc)
vector_sample.append(self.model.ops.alloc1f(nO))
assert len(doc_sample) > 0, Errors.E923.format(name=self.name)
assert len(vector_sample) > 0, Errors.E923.format(name=self.name)
# XXX In order for size estimation to work, there has to be at least
# one entity. It's not used for training so it doesn't have to be real,
# so we add a fake one if none are present.
# We can't use Doc.has_annotation here because it can be True for docs
# that have been through an NER component but got no entities.
has_annotations = any([doc.ents for doc in doc_sample])
if not has_annotations:
doc = doc_sample[0]
ent = doc[0:1]
ent.label_ = "XXX"
doc.ents = (ent,)
self.model.initialize(
X=doc_sample, Y=self.model.ops.asarray(vector_sample, dtype="float32")
)
if not has_annotations:
# Clean up dummy annotation
doc.ents = []
def batch_has_learnable_example(self, examples):
"""Check if a batch contains a learnable example.
If one isn't present, then the update step needs to be skipped.
"""
for eg in examples:
for ent in eg.predicted.ents:
candidates = list(self.get_candidates(self.kb, ent))
if candidates:
return True
return False
def update(
self,
examples: Iterable[Example],
*,
drop: float = 0.0,
sgd: Optional[Optimizer] = None,
losses: Optional[Dict[str, float]] = None,
) -> Dict[str, float]:
"""Learn from a batch of documents and gold-standard information,
updating the pipe's model. Delegates to predict and get_loss.
examples (Iterable[Example]): A batch of Example objects.
drop (float): The dropout rate.
sgd (thinc.api.Optimizer): The optimizer.
losses (Dict[str, float]): Optional record of the loss during training.
Updated using the component name as the key.
RETURNS (Dict[str, float]): The updated losses dictionary.
DOCS: https://spacy.io/api/entitylinker#update
"""
self.validate_kb()
if losses is None:
losses = {}
losses.setdefault(self.name, 0.0)
if not examples:
return losses
validate_examples(examples, "EntityLinker.update")
set_dropout_rate(self.model, drop)
docs = [eg.predicted for eg in examples]
# save to restore later
old_ents = [doc.ents for doc in docs]
for doc, ex in zip(docs, examples):
if self.use_gold_ents:
ents, _ = ex.get_aligned_ents_and_ner()
doc.ents = ents
else:
# only keep matching ents
doc.ents = ex.get_matching_ents()
# make sure we have something to learn from, if not, short-circuit
if not self.batch_has_learnable_example(examples):
return losses
sentence_encodings, bp_context = self.model.begin_update(docs)
# now restore the ents
for doc, old in zip(docs, old_ents):
doc.ents = old
loss, d_scores = self.get_loss(
sentence_encodings=sentence_encodings, examples=examples
)
bp_context(d_scores)
if sgd is not None:
self.finish_update(sgd)
losses[self.name] += loss
return losses
def get_loss(self, examples: Iterable[Example], sentence_encodings: Floats2d):
validate_examples(examples, "EntityLinker.get_loss")
entity_encodings = []
eidx = 0 # indices in gold entities to keep
keep_ents = [] # indices in sentence_encodings to keep
for eg in examples:
kb_ids = eg.get_aligned("ENT_KB_ID", as_string=True)
for ent in eg.get_matching_ents():
kb_id = kb_ids[ent.start]
if kb_id:
entity_encoding = self.kb.get_vector(kb_id)
entity_encodings.append(entity_encoding)
keep_ents.append(eidx)
eidx += 1
entity_encodings = self.model.ops.asarray2f(entity_encodings, dtype="float32")
selected_encodings = sentence_encodings[keep_ents]
# if there are no matches, short circuit
if not keep_ents:
out = self.model.ops.alloc2f(*sentence_encodings.shape)
return 0, out
if selected_encodings.shape != entity_encodings.shape:
err = Errors.E147.format(
method="get_loss", msg="gold entities do not match up"
)
raise RuntimeError(err)
gradients = self.distance.get_grad(selected_encodings, entity_encodings)
# to match the input size, we need to give a zero gradient for items not in the kb
out = self.model.ops.alloc2f(*sentence_encodings.shape)
out[keep_ents] = gradients
loss = self.distance.get_loss(selected_encodings, entity_encodings)
loss = loss / len(entity_encodings)
return float(loss), out
def predict(self, docs: Iterable[Doc]) -> List[str]:
"""Apply the pipeline's model to a batch of docs, without modifying them.
Returns the KB IDs for each entity in each doc, including NIL if there is
no prediction.
docs (Iterable[Doc]): The documents to predict.
RETURNS (List[str]): The models prediction for each document.
DOCS: https://spacy.io/api/entitylinker#predict
"""
self.validate_kb()
entity_count = 0
final_kb_ids: List[str] = []
xp = self.model.ops.xp
if not docs:
return final_kb_ids
if isinstance(docs, Doc):
docs = [docs]
for i, doc in enumerate(docs):
if len(doc) == 0:
continue
sentences = [s for s in doc.sents]
# Loop over entities in batches.
for ent_idx in range(0, len(doc.ents), self.candidates_batch_size):
ent_batch = doc.ents[ent_idx : ent_idx + self.candidates_batch_size]
# Look up candidate entities.
valid_ent_idx = [
idx
for idx in range(len(ent_batch))
if ent_batch[idx].label_ not in self.labels_discard
]
batch_candidates = list(
self.get_candidates_batch(
self.kb, [ent_batch[idx] for idx in valid_ent_idx]
)
if self.candidates_batch_size > 1
else [
self.get_candidates(self.kb, ent_batch[idx])
for idx in valid_ent_idx
]
)
# Looping through each entity in batch (TODO: rewrite)
for j, ent in enumerate(ent_batch):
assert hasattr(ent, "sents")
sents = list(ent.sents)
sent_indices = (
sentences.index(sents[0]),
sentences.index(sents[-1]),
)
assert sent_indices[1] >= sent_indices[0] >= 0
if self.incl_context:
# get n_neighbour sentences, clipped to the length of the document
start_sentence = max(0, sent_indices[0] - self.n_sents)
end_sentence = min(
len(sentences) - 1, sent_indices[1] + self.n_sents
)
start_token = sentences[start_sentence].start
end_token = sentences[end_sentence].end
sent_doc = doc[start_token:end_token].as_doc()
# currently, the context is the same for each entity in a sentence (should be refined)
sentence_encoding = self.model.predict([sent_doc])[0]
sentence_encoding_t = sentence_encoding.T
sentence_norm = xp.linalg.norm(sentence_encoding_t)
entity_count += 1
if ent.label_ in self.labels_discard:
# ignoring this entity - setting to NIL
final_kb_ids.append(self.NIL)
else:
candidates = list(batch_candidates[j])
if not candidates:
# no prediction possible for this entity - setting to NIL
final_kb_ids.append(self.NIL)
elif len(candidates) == 1 and self.threshold is None:
# shortcut for efficiency reasons: take the 1 candidate
final_kb_ids.append(candidates[0].entity_)
else:
random.shuffle(candidates)
# set all prior probabilities to 0 if incl_prior=False
prior_probs = xp.asarray([c.prior_prob for c in candidates])
if not self.incl_prior:
prior_probs = xp.asarray([0.0 for _ in candidates])
scores = prior_probs
# add in similarity from the context
if self.incl_context:
entity_encodings = xp.asarray(
[c.entity_vector for c in candidates]
)
entity_norm = xp.linalg.norm(entity_encodings, axis=1)
if len(entity_encodings) != len(prior_probs):
raise RuntimeError(
Errors.E147.format(
method="predict",
msg="vectors not of equal length",
)
)
# cosine similarity
sims = xp.dot(entity_encodings, sentence_encoding_t) / (
sentence_norm * entity_norm
)
if sims.shape != prior_probs.shape:
raise ValueError(Errors.E161)
scores = prior_probs + sims - (prior_probs * sims)
final_kb_ids.append(
candidates[scores.argmax().item()].entity_
if self.threshold is None
or scores.max() >= self.threshold
else EntityLinker.NIL
)
if not (len(final_kb_ids) == entity_count):
err = Errors.E147.format(
method="predict", msg="result variables not of equal length"
)
raise RuntimeError(err)
return final_kb_ids
def set_annotations(self, docs: Iterable[Doc], kb_ids: List[str]) -> None:
"""Modify a batch of documents, using pre-computed scores.
docs (Iterable[Doc]): The documents to modify.
kb_ids (List[str]): The IDs to set, produced by EntityLinker.predict.
DOCS: https://spacy.io/api/entitylinker#set_annotations
"""
count_ents = len([ent for doc in docs for ent in doc.ents])
if count_ents != len(kb_ids):
raise ValueError(Errors.E148.format(ents=count_ents, ids=len(kb_ids)))
i = 0
overwrite = self.cfg["overwrite"]
for doc in docs:
for ent in doc.ents:
kb_id = kb_ids[i]
i += 1
for token in ent:
if token.ent_kb_id == 0 or overwrite:
token.ent_kb_id_ = kb_id
def to_bytes(self, *, exclude=tuple()):
"""Serialize the pipe to a bytestring.
exclude (Iterable[str]): String names of serialization fields to exclude.
RETURNS (bytes): The serialized object.
DOCS: https://spacy.io/api/entitylinker#to_bytes
"""
self._validate_serialization_attrs()
serialize = {}
if hasattr(self, "cfg") and self.cfg is not None:
serialize["cfg"] = lambda: srsly.json_dumps(self.cfg)
serialize["vocab"] = lambda: self.vocab.to_bytes(exclude=exclude)
serialize["kb"] = self.kb.to_bytes
serialize["model"] = self.model.to_bytes
return util.to_bytes(serialize, exclude)
def from_bytes(self, bytes_data, *, exclude=tuple()):
"""Load the pipe from a bytestring.
exclude (Iterable[str]): String names of serialization fields to exclude.
RETURNS (TrainablePipe): The loaded object.
DOCS: https://spacy.io/api/entitylinker#from_bytes
"""
self._validate_serialization_attrs()
def load_model(b):
try:
self.model.from_bytes(b)
except AttributeError:
raise ValueError(Errors.E149) from None
deserialize = {}
if hasattr(self, "cfg") and self.cfg is not None:
deserialize["cfg"] = lambda b: self.cfg.update(srsly.json_loads(b))
deserialize["vocab"] = lambda b: self.vocab.from_bytes(b, exclude=exclude)
deserialize["kb"] = lambda b: self.kb.from_bytes(b)
deserialize["model"] = load_model
util.from_bytes(bytes_data, deserialize, exclude)
return self
def to_disk(
self, path: Union[str, Path], *, exclude: Iterable[str] = SimpleFrozenList()
) -> None:
"""Serialize the pipe to disk.
path (str / Path): Path to a directory.
exclude (Iterable[str]): String names of serialization fields to exclude.
DOCS: https://spacy.io/api/entitylinker#to_disk
"""
serialize = {}
serialize["vocab"] = lambda p: self.vocab.to_disk(p, exclude=exclude)
serialize["cfg"] = lambda p: srsly.write_json(p, self.cfg)
serialize["kb"] = lambda p: self.kb.to_disk(p)
serialize["model"] = lambda p: self.model.to_disk(p)
util.to_disk(path, serialize, exclude)
def from_disk(
self, path: Union[str, Path], *, exclude: Iterable[str] = SimpleFrozenList()
) -> "EntityLinker":
"""Load the pipe from disk. Modifies the object in place and returns it.
path (str / Path): Path to a directory.
exclude (Iterable[str]): String names of serialization fields to exclude.
RETURNS (EntityLinker): The modified EntityLinker object.
DOCS: https://spacy.io/api/entitylinker#from_disk
"""
def load_model(p):
try:
with p.open("rb") as infile:
self.model.from_bytes(infile.read())
except AttributeError:
raise ValueError(Errors.E149) from None
deserialize: Dict[str, Callable[[Any], Any]] = {}
deserialize["cfg"] = lambda p: self.cfg.update(deserialize_config(p))
deserialize["vocab"] = lambda p: self.vocab.from_disk(p, exclude=exclude)
deserialize["kb"] = lambda p: self.kb.from_disk(p)
deserialize["model"] = load_model
util.from_disk(path, deserialize, exclude)
return self
def rehearse(self, examples, *, sgd=None, losses=None, **config):
raise NotImplementedError
def add_label(self, label):
raise NotImplementedError