from functools import lru_cache from typing import cast, Any, Callable, Dict, Iterable, List, Optional from typing import Sequence, Tuple, Union from collections import Counter from copy import deepcopy from itertools import islice import numpy as np import srsly from thinc.api import Config, Model, SequenceCategoricalCrossentropy, NumpyOps from thinc.types import Floats2d, Ints2d from spacy.pipeline._edit_tree_internals.edit_trees import EditTrees from spacy.pipeline._edit_tree_internals.schemas import validate_edit_tree from spacy.pipeline.lemmatizer import lemmatizer_score from spacy.pipeline.trainable_pipe import TrainablePipe from spacy.errors import Errors from spacy.language import Language from spacy.tokens import Doc, Token from spacy.training import Example, validate_examples, validate_get_examples from spacy.vocab import Vocab from spacy import util TOP_K_GUARDRAIL = 20 default_model_config = """ [model] @architectures = "spacy.Tagger.v2" [model.tok2vec] @architectures = "spacy.HashEmbedCNN.v2" pretrained_vectors = null width = 96 depth = 4 embed_size = 2000 window_size = 1 maxout_pieces = 3 subword_features = true """ DEFAULT_EDIT_TREE_LEMMATIZER_MODEL = Config().from_str(default_model_config)["model"] @Language.factory( "trainable_lemmatizer_v2", assigns=["token.lemma"], requires=[], default_config={ "model": DEFAULT_EDIT_TREE_LEMMATIZER_MODEL, "backoff": "orth", "min_tree_freq": 3, "overwrite": False, "top_k": 1, "overwrite_labels": True, "scorer": {"@scorers": "spacy.lemmatizer_scorer.v1"}, }, default_score_weights={"lemma_acc": 1.0}, ) def make_edit_tree_lemmatizer( nlp: Language, name: str, model: Model, backoff: Optional[str], min_tree_freq: int, overwrite: bool, top_k: int, overwrite_labels: bool, scorer: Optional[Callable], ): """Construct an EditTreeLemmatizer component.""" return EditTreeLemmatizer( nlp.vocab, model, name, backoff=backoff, min_tree_freq=min_tree_freq, overwrite=overwrite, top_k=top_k, overwrite_labels=overwrite_labels, scorer=scorer, ) # _f = open("lemmatizer.log", "w") # def debug(*args): # _f.write(" ".join(args) + "\n") def debug(*args): pass class EditTreeLemmatizer(TrainablePipe): """ Lemmatizer that lemmatizes each word using a predicted edit tree. """ def __init__( self, vocab: Vocab, model: Model, name: str = "trainable_lemmatizer", *, backoff: Optional[str] = "orth", min_tree_freq: int = 3, overwrite: bool = False, top_k: int = 1, overwrite_labels, scorer: Optional[Callable] = lemmatizer_score, ): """ Construct an edit tree lemmatizer. backoff (Optional[str]): backoff to use when the predicted edit trees are not applicable. Must be an attribute of Token or None (leave the lemma unset). min_tree_freq (int): prune trees that are applied less than this frequency in the training data. overwrite (bool): overwrite existing lemma annotations. top_k (int): try to apply at most the k most probable edit trees. """ self.vocab = vocab self.model = model self.name = name self.backoff = backoff self.min_tree_freq = min_tree_freq self.overwrite = overwrite self.top_k = top_k self.overwrite_labels = overwrite_labels self.trees = EditTrees(self.vocab.strings) self.tree2label: Dict[int, int] = {} self.cfg: Dict[str, Any] = {"labels": []} self.scorer = scorer self.numpy_ops = NumpyOps() def get_loss( self, examples: Iterable[Example], scores: List[Floats2d] ) -> Tuple[float, List[Floats2d]]: validate_examples(examples, "EditTreeLemmatizer.get_loss") loss_func = SequenceCategoricalCrossentropy(normalize=False, missing_value=-1) truths = [] for eg in examples: eg_truths = [] for (predicted, gold_lemma, gold_pos, gold_sent_start) in zip( eg.predicted, eg.get_aligned("LEMMA", as_string=True), eg.get_aligned("POS", as_string=True), eg.get_aligned_sent_starts(), ): if gold_lemma is None: label = -1 else: form = self._get_true_cased_form( predicted.text, gold_sent_start, gold_pos ) tree_id = self.trees.add(form, gold_lemma) # debug(f"@get_loss: {predicted}/{gold_pos}[{gold_sent_start}]->{form}|{gold_lemma}[{tree_id}]") label = self.tree2label.get(tree_id, 0) eg_truths.append(label) truths.append(eg_truths) d_scores, loss = loss_func(scores, truths) if self.model.ops.xp.isnan(loss): raise ValueError(Errors.E910.format(name=self.name)) return float(loss), d_scores def predict(self, docs: Iterable[Doc]) -> List[Ints2d]: if self.top_k == 1: scores2guesses = self._scores2guesses_top_k_equals_1 elif self.top_k <= TOP_K_GUARDRAIL: scores2guesses = self._scores2guesses_top_k_greater_1 else: scores2guesses = self._scores2guesses_top_k_guardrail # The behaviour of *_scores2guesses_top_k_greater_1()* is efficient for values # of *top_k>1* that are likely to be useful when the edit tree lemmatizer is used # for its principal purpose of lemmatizing tokens. However, the code could also # be used for other purposes, and with very large values of *top_k* the method # becomes inefficient. In such cases, *_scores2guesses_top_k_guardrail()* is used # instead. n_docs = len(list(docs)) if not any(len(doc) for doc in docs): # Handle cases where there are no tokens in any docs. n_labels = len(self.cfg["labels"]) guesses: List[Ints2d] = [self.model.ops.alloc2i(0, n_labels) for _ in docs] assert len(guesses) == n_docs return guesses scores = self.model.predict(docs) assert len(scores) == n_docs guesses = scores2guesses(docs, scores) assert len(guesses) == n_docs return guesses def _scores2guesses_top_k_equals_1(self, docs, scores): guesses = [] for doc, doc_scores in zip(docs, scores): doc_guesses = doc_scores.argmax(axis=1) doc_guesses = self.numpy_ops.asarray(doc_guesses) doc_compat_guesses = [] for i, token in enumerate(doc): tree_id = self.cfg["labels"][doc_guesses[i]] form: str = self._get_true_cased_form_of_token(token) if self.trees.apply(tree_id, form) is not None: doc_compat_guesses.append(tree_id) else: doc_compat_guesses.append(-1) guesses.append(np.array(doc_compat_guesses)) return guesses def _scores2guesses_top_k_greater_1(self, docs, scores): guesses = [] top_k = min(self.top_k, len(self.labels)) for doc, doc_scores in zip(docs, scores): doc_scores = self.numpy_ops.asarray(doc_scores) doc_compat_guesses = [] for i, token in enumerate(doc): for _ in range(top_k): candidate = int(doc_scores[i].argmax()) candidate_tree_id = self.cfg["labels"][candidate] form: str = self._get_true_cased_form_of_token(token) if self.trees.apply(candidate_tree_id, form) is not None: doc_compat_guesses.append(candidate_tree_id) break doc_scores[i, candidate] = np.finfo(np.float32).min else: doc_compat_guesses.append(-1) guesses.append(np.array(doc_compat_guesses)) return guesses def _scores2guesses_top_k_guardrail(self, docs, scores): guesses = [] for doc, doc_scores in zip(docs, scores): doc_guesses = np.argsort(doc_scores)[..., : -self.top_k - 1 : -1] doc_guesses = self.numpy_ops.asarray(doc_guesses) doc_compat_guesses = [] for token, candidates in zip(doc, doc_guesses): tree_id = -1 for candidate in candidates: candidate_tree_id = self.cfg["labels"][candidate] form: str = self._get_true_cased_form_of_token(token) if self.trees.apply(candidate_tree_id, form) is not None: tree_id = candidate_tree_id break doc_compat_guesses.append(tree_id) guesses.append(np.array(doc_compat_guesses)) return guesses def set_annotations(self, docs: Iterable[Doc], batch_tree_ids): for i, doc in enumerate(docs): doc_tree_ids = batch_tree_ids[i] if hasattr(doc_tree_ids, "get"): doc_tree_ids = doc_tree_ids.get() for j, tree_id in enumerate(doc_tree_ids): if self.overwrite or doc[j].lemma == 0: # If no applicable tree could be found during prediction, # the special identifier -1 is used. Otherwise the tree # is guaranteed to be applicable. if tree_id == -1: if self.backoff is not None: doc[j].lemma = getattr(doc[j], self.backoff) else: form = self._get_true_cased_form_of_token(doc[j]) lemma = self.trees.apply(tree_id, form) or form # debug(f"@set_annotations: {doc[j]}/{doc[j].pos_}[{doc[j].is_sent_start}]->{form}|{lemma}[{tree_id}]") doc[j].lemma_ = lemma @property def labels(self) -> Tuple[int, ...]: """Returns the labels currently added to the component.""" return tuple(self.cfg["labels"]) @property def hide_labels(self) -> bool: return True @property def label_data(self) -> Dict: trees = [] for tree_id in range(len(self.trees)): tree = self.trees[tree_id] if "orig" in tree: tree["orig"] = self.vocab.strings[tree["orig"]] if "subst" in tree: tree["subst"] = self.vocab.strings[tree["subst"]] trees.append(tree) return dict(trees=trees, labels=tuple(self.cfg["labels"])) def initialize( self, get_examples: Callable[[], Iterable[Example]], *, nlp: Optional[Language] = None, labels: Optional[Dict] = None, ): validate_get_examples(get_examples, "EditTreeLemmatizer.initialize") if self.overwrite_labels: if labels is None: self._labels_from_data(get_examples) else: self._add_labels(labels) # Sample for the model. doc_sample = [] label_sample = [] for example in islice(get_examples(), 10): doc_sample.append(example.x) gold_labels: List[List[float]] = [] for token in example.reference: if token.lemma == 0: gold_label = None else: gold_label = self._pair2label(token.text, token.lemma_) gold_labels.append( [ 1.0 if label == gold_label else 0.0 for label in self.cfg["labels"] ] ) gold_labels = cast(Floats2d, gold_labels) label_sample.append(self.model.ops.asarray(gold_labels, dtype="float32")) self._require_labels() assert len(doc_sample) > 0, Errors.E923.format(name=self.name) assert len(label_sample) > 0, Errors.E923.format(name=self.name) self.model.initialize(X=doc_sample, Y=label_sample) def from_bytes(self, bytes_data, *, exclude=tuple()): deserializers = { "cfg": lambda b: self.cfg.update(srsly.json_loads(b)), "model": lambda b: self.model.from_bytes(b), "vocab": lambda b: self.vocab.from_bytes(b, exclude=exclude), "trees": lambda b: self.trees.from_bytes(b), } util.from_bytes(bytes_data, deserializers, exclude) return self def to_bytes(self, *, exclude=tuple()): serializers = { "cfg": lambda: srsly.json_dumps(self.cfg), "model": lambda: self.model.to_bytes(), "vocab": lambda: self.vocab.to_bytes(exclude=exclude), "trees": lambda: self.trees.to_bytes(), } return util.to_bytes(serializers, exclude) def to_disk(self, path, exclude=tuple()): path = util.ensure_path(path) serializers = { "cfg": lambda p: srsly.write_json(p, self.cfg), "model": lambda p: self.model.to_disk(p), "vocab": lambda p: self.vocab.to_disk(p, exclude=exclude), "trees": lambda p: self.trees.to_disk(p), } util.to_disk(path, serializers, exclude) def from_disk(self, path, exclude=tuple()): def load_model(p): try: with open(p, "rb") as mfile: self.model.from_bytes(mfile.read()) except AttributeError: raise ValueError(Errors.E149) from None deserializers = { "cfg": lambda p: self.cfg.update(srsly.read_json(p)), "model": load_model, "vocab": lambda p: self.vocab.from_disk(p, exclude=exclude), "trees": lambda p: self.trees.from_disk(p), } util.from_disk(path, deserializers, exclude) return self def _add_labels(self, labels: Dict): if "labels" not in labels: raise ValueError(Errors.E857.format(name="labels")) if "trees" not in labels: raise ValueError(Errors.E857.format(name="trees")) self.cfg["labels"] = list(labels["labels"]) trees = [] for tree in labels["trees"]: errors = validate_edit_tree(tree) if errors: raise ValueError(Errors.E1026.format(errors="\n".join(errors))) tree = dict(tree) if "orig" in tree: tree["orig"] = self.vocab.strings[tree["orig"]] if "orig" in tree: tree["subst"] = self.vocab.strings[tree["subst"]] trees.append(tree) self.trees.from_json(trees) for label, tree in enumerate(self.labels): self.tree2label[tree] = label def _labels_from_data(self, get_examples: Callable[[], Iterable[Example]]): # Count corpus tree frequencies in ad-hoc storage to avoid cluttering # the final pipe/string store. vocab = Vocab() trees = EditTrees(vocab.strings) tree_freqs: Counter = Counter() repr_pairs: Dict = {} for example in get_examples(): for token in example.reference: if token.lemma != 0: form = self._get_true_cased_form_of_token(token) # debug("_labels_from_data", str(token) + "->" + form, token.lemma_) tree_id = trees.add(form, token.lemma_) tree_freqs[tree_id] += 1 repr_pairs[tree_id] = (form, token.lemma_) # Construct trees that make the frequency cut-off using representative # form - token pairs. for tree_id, freq in tree_freqs.items(): if freq >= self.min_tree_freq: form, lemma = repr_pairs[tree_id] self._pair2label(form, lemma, add_label=True) @lru_cache() def _get_true_cased_form(self, token: str, is_sent_start: bool, pos: str) -> str: if is_sent_start and pos != "PROPN": return token.lower() else: return token def _get_true_cased_form_of_token(self, token: Token) -> str: return self._get_true_cased_form(token.text, token.is_sent_start, token.pos_) def _pair2label(self, form, lemma, add_label=False): """ Look up the edit tree identifier for a form/label pair. If the edit tree is unknown and "add_label" is set, the edit tree will be added to the labels. """ tree_id = self.trees.add(form, lemma) if tree_id not in self.tree2label: if not add_label: return None self.tree2label[tree_id] = len(self.cfg["labels"]) self.cfg["labels"].append(tree_id) return self.tree2label[tree_id]