Introduce hierarchy for EL Candidate objects (#12341)

* Convert Candidate from Cython to Python class.

* Format.

* Fix .entity_ typo in _add_activations() usage.

* Update spacy/kb/candidate.py

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Update doc string of BaseCandidate.__init__().

* Update spacy/kb/candidate.py

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Rename Candidate to InMemoryCandidate, BaseCandidate to Candidate.

* Adjust Candidate to support and mandate numerical entity IDs.

* Format.

* Fix docstring and docs.

* Update website/docs/api/kb.mdx

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Rename alias -> mention.

* Refactor Candidate attribute names. Update docs and tests accordingly.

* Refacor Candidate attributes and their usage.

* Format.

* Fix mypy error.

* Update error code in line with v4 convention.

* Update spacy/kb/candidate.py

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Updated error code.

* Simplify interface for int/str representations.

* Update website/docs/api/kb.mdx

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Rename 'alias' to 'mention'.

* Port Candidate and InMemoryCandidate to Cython.

* Remove redundant entry in setup.py.

* Add abstract class check.

* Drop storing mention.

* Update spacy/kb/candidate.pxd

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Fix entity_id refactoring problems in docstrings.

* Drop unused InMemoryCandidate._entity_hash.

* Update docstrings.

* Move attributes out of Candidate.

* Partially fix alias/mention terminology usage. Convert Candidate to interface.

* Remove prior_prob from supported properties in Candidate. Introduce KnowledgeBase.supports_prior_probs().

* Update docstrings related to prior_prob.

* Update alias/mention usage in doc(strings).

* Update spacy/ml/models/entity_linker.py

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Update spacy/ml/models/entity_linker.py

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Mention -> alias renaming. Drop Candidate.mentions(). Drop InMemoryLookupKB.get_alias_candidates() from docs.

* Update docstrings.

* Fix InMemoryCandidate attribute names.

* Update spacy/kb/kb.pyx

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Update spacy/ml/models/entity_linker.py

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Update W401 test.

* Update spacy/errors.py

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Update spacy/kb/kb.pyx

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

* Use Candidate output type for toy generators in the test suite to mimick best practices

* fix docs

* fix import

---------

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

spacy/errors.py

@@ -82,7 +82,7 @@ class Warnings(metaclass=ErrorsWithCodes):
             "ignoring the duplicate entry.")
     W021 = ("Unexpected hash collision in PhraseMatcher. Matches may be "
             "incorrect. Modify PhraseMatcher._terminal_hash to fix.")
-    W024 = ("Entity '{entity}' - Alias '{alias}' combination already exists in "
+    W024 = ("Entity '{entity}' - alias '{alias}' combination already exists in "
             "the Knowledge Base.")
     W026 = ("Unable to set all sentence boundaries from dependency parses. If "
             "you are constructing a parse tree incrementally by setting "
@@ -209,7 +209,11 @@ class Warnings(metaclass=ErrorsWithCodes):
             "`enabled` ({enabled}). Be aware that this might affect other components in your pipeline.")
     W124 = ("{host}:{port} is already in use, using the nearest available port {serve_port} as an alternative.")
 
+    # v4 warning strings
     W400 = ("`use_upper=False` is ignored, the upper layer is always enabled")
+    W401 = ("`incl_prior is True`, but the selected knowledge base type {kb_type} doesn't support prior probability "
+            "lookups so this setting will be ignored. If your KB does support prior probability lookups, make sure "
+            "to return `True` in `.supports_prior_probs`.")
 
 
 class Errors(metaclass=ErrorsWithCodes):
@@ -961,6 +965,8 @@ class Errors(metaclass=ErrorsWithCodes):
              "reference and predicted docs.")
     E4004 = ("Backprop is not supported when is_train is not set.")
     E4005 = ("EntityLinker_v1 is not supported in spaCy v4. Update your configuration.")
+    E4006 = ("Expected `entity_id` to be of type {exp_type}, but is of type {found_type}.")
+
 
 RENAMED_LANGUAGE_CODES = {"xx": "mul", "is": "isl"}
 

spacy/kb/__init__.py

@@ -1,3 +1,6 @@
 from .kb import KnowledgeBase
 from .kb_in_memory import InMemoryLookupKB
-from .candidate import Candidate, get_candidates, get_candidates_batch
+from .candidate import Candidate, InMemoryCandidate
+
+
+__all__ = ["KnowledgeBase", "InMemoryLookupKB", "Candidate", "InMemoryCandidate"]

spacy/kb/candidate.pxd

@@ -1,12 +1,15 @@
-from .kb cimport KnowledgeBase
 from libcpp.vector cimport vector
+from .kb_in_memory cimport InMemoryLookupKB
 from ..typedefs cimport hash_t
 
-# Object used by the Entity Linker that summarizes one entity-alias candidate combination.
 cdef class Candidate:
-    cdef readonly KnowledgeBase kb
+    pass
-    cdef hash_t entity_hash
+
-    cdef float entity_freq
+
-    cdef vector[float] entity_vector
+cdef class InMemoryCandidate(Candidate):
-    cdef hash_t alias_hash
+    cdef readonly hash_t _entity_hash
-    cdef float prior_prob
+    cdef readonly hash_t _alias_hash
+    cpdef vector[float] _entity_vector
+    cdef float _prior_prob
+    cdef readonly InMemoryLookupKB _kb
+    cdef float _entity_freq

spacy/kb/candidate.pyx

@@ -1,74 +1,96 @@
 # cython: infer_types=True, profile=True
 
-from typing import Iterable
+from .kb_in_memory cimport InMemoryLookupKB
-from .kb cimport KnowledgeBase
+from ..errors import Errors
-from ..tokens import Span
 
 cdef class Candidate:
-    """A `Candidate` object refers to a textual mention (`alias`) that may or may not be resolved
+    """A `Candidate` object refers to a textual mention that may or may not be resolved
-    to a specific `entity` from a Knowledge Base. This will be used as input for the entity linking
+    to a specific entity from a Knowledge Base. This will be used as input for the entity linking
     algorithm which will disambiguate the various candidates to the correct one.
-    Each candidate (alias, entity) pair is assigned a certain prior probability.
+    Each candidate, which represents a possible link between one textual mention and one entity in the knowledge base,
+    is assigned a certain prior probability.
 
     DOCS: https://spacy.io/api/kb/#candidate-init
     """
 
-    def __init__(self, KnowledgeBase kb, entity_hash, entity_freq, entity_vector, alias_hash, prior_prob):
+    def __init__(self):
-        self.kb = kb
+        # Make sure abstract Candidate is not instantiated.
-        self.entity_hash = entity_hash
+        if self.__class__ == Candidate:
-        self.entity_freq = entity_freq
+            raise TypeError(
-        self.entity_vector = entity_vector
+                Errors.E1046.format(cls_name=self.__class__.__name__)
-        self.alias_hash = alias_hash
+            )
-        self.prior_prob = prior_prob
 
     @property
-    def entity(self) -> int:
+    def entity_id(self) -> int:
-        """RETURNS (uint64): hash of the entity's KB ID/name"""
+        """RETURNS (int): Numerical representation of entity ID (if entity ID is numerical, this is just the entity ID,
-        return self.entity_hash
+        otherwise the hash of the entity ID string)."""
+        raise NotImplementedError
 
     @property
-    def entity_(self) -> str:
+    def entity_id_(self) -> str:
-        """RETURNS (str): ID/name of this entity in the KB"""
+        """RETURNS (str): String representation of entity ID."""
-        return self.kb.vocab.strings[self.entity_hash]
+        raise NotImplementedError
 
     @property
-    def alias(self) -> int:
+    def entity_vector(self) -> vector[float]:
-        """RETURNS (uint64): hash of the alias"""
+        """RETURNS (vector[float]): Entity vector."""
-        return self.alias_hash
+        raise NotImplementedError
+
+
+cdef class InMemoryCandidate(Candidate):
+    """Candidate for InMemoryLookupKB."""
+
+    def __init__(
+        self,
+        kb: InMemoryLookupKB,
+        entity_hash: int,
+        alias_hash: int,
+        entity_vector: vector[float],
+        prior_prob: float,
+        entity_freq: float
+    ):
+        """
+        kb (InMemoryLookupKB]): InMemoryLookupKB instance.
+        entity_id (int): Entity ID as hash that can be looked up with InMemoryKB.vocab.strings.__getitem__().
+        entity_freq (int): Entity frequency in KB corpus.
+        entity_vector (List[float]): Entity embedding.
+        alias_hash (int): Alias hash.
+        prior_prob (float): Prior probability of entity for this alias. I. e. the probability that, independent of
+            the context, this alias - which matches one of this entity's aliases - resolves to one this entity.
+        """
+        super().__init__()
+
+        self._entity_hash = entity_hash
+        self._entity_vector = entity_vector
+        self._prior_prob = prior_prob
+        self._kb = kb
+        self._alias_hash = alias_hash
+        self._entity_freq = entity_freq
 
     @property
-    def alias_(self) -> str:
+    def entity_id(self) -> int:
-        """RETURNS (str): ID of the original alias"""
+        return self._entity_hash
-        return self.kb.vocab.strings[self.alias_hash]
 
     @property
-    def entity_freq(self) -> float:
+    def entity_vector(self) -> vector[float]:
-        return self.entity_freq
+        return self._entity_vector
-
-    @property
-    def entity_vector(self) -> Iterable[float]:
-        return self.entity_vector
 
     @property
     def prior_prob(self) -> float:
-        return self.prior_prob
+        """RETURNS (float): Prior probability that this alias, which matches one of this entity's synonyms, resolves to
+        this entity."""
+        return self._prior_prob
 
+    @property
+    def alias(self) -> str:
+        """RETURNS (str): Alias."""
+        return self._kb.vocab.strings[self._alias_hash]
 
-def get_candidates(kb: KnowledgeBase, mention: Span) -> Iterable[Candidate]:
+    @property
-    """
+    def entity_id_(self) -> str:
-    Return candidate entities for a given mention and fetching appropriate entries from the index.
+        return self._kb.vocab.strings[self._entity_hash]
-    kb (KnowledgeBase): Knowledge base to query.
-    mention (Span): Entity mention for which to identify candidates.
-    RETURNS (Iterable[Candidate]): Identified candidates.
-    """
-    return kb.get_candidates(mention)
 
-
+    @property
-def get_candidates_batch(kb: KnowledgeBase, mentions: Iterable[Span]) -> Iterable[Iterable[Candidate]]:
+    def entity_freq(self) -> float:
-    """
+        """RETURNS (float): Entity frequency in KB corpus."""
-    Return candidate entities for the given mentions and fetching appropriate entries from the index.
+        return self._entity_freq
-    kb (KnowledgeBase): Knowledge base to query.
-    mention (Iterable[Span]): Entity mentions for which to identify candidates.
-    RETURNS (Iterable[Iterable[Candidate]]): Identified candidates.
-    """
-    return kb.get_candidates_batch(mentions)

spacy/kb/kb.pyx

@@ -32,9 +32,10 @@ cdef class KnowledgeBase:
 
     def get_candidates_batch(self, mentions: Iterable[Span]) -> Iterable[Iterable[Candidate]]:
         """
-        Return candidate entities for specified texts. Each candidate defines the entity, the original alias,
+        Return candidate entities for a specified Span mention. Each candidate defines at least the entity and the
-        and the prior probability of that alias resolving to that entity.
+        entity's embedding vector. Depending on the KB implementation, further properties - such as the prior
-        If no candidate is found for a given text, an empty list is returned.
+        probability of the specified mention text resolving to that entity - might be included.
+        If no candidates are found for a given mention, an empty list is returned.
         mentions (Iterable[Span]): Mentions for which to get candidates.
         RETURNS (Iterable[Iterable[Candidate]]): Identified candidates.
         """
@@ -42,9 +43,10 @@ cdef class KnowledgeBase:
 
     def get_candidates(self, mention: Span) -> Iterable[Candidate]:
         """
-        Return candidate entities for specified text. Each candidate defines the entity, the original alias,
+        Return candidate entities for a specific mention. Each candidate defines at least the entity and the
-        and the prior probability of that alias resolving to that entity.
+        entity's embedding vector. Depending on the KB implementation, further properties - such as the prior
-        If the no candidate is found for a given text, an empty list is returned.
+        probability of the specified mention text resolving to that entity - might be included.
+        If no candidate is found for the given mention, an empty list is returned.
         mention (Span): Mention for which to get candidates.
         RETURNS (Iterable[Candidate]): Identified candidates.
         """
@@ -106,3 +108,10 @@ cdef class KnowledgeBase:
         raise NotImplementedError(
             Errors.E1045.format(parent="KnowledgeBase", method="from_disk", name=self.__name__)
         )
+
+    @property
+    def supports_prior_probs(self) -> bool:
+        """RETURNS (bool): Whether this KB type supports looking up prior probabilities for entity mentions."""
+        raise NotImplementedError(
+            Errors.E1045.format(parent="KnowledgeBase", method="supports_prior_probs", name=self.__name__)
+        )

spacy/kb/kb_in_memory.pyx

@@ -18,7 +18,7 @@ from .. import util
 from ..util import SimpleFrozenList, ensure_path
 from ..vocab cimport Vocab
 from .kb cimport KnowledgeBase
-from .candidate import Candidate as Candidate
+from .candidate import InMemoryCandidate
 
 
 cdef class InMemoryLookupKB(KnowledgeBase):
@@ -226,10 +226,10 @@ cdef class InMemoryLookupKB(KnowledgeBase):
             alias_entry.probs = probs
             self._aliases_table[alias_index] = alias_entry
 
-    def get_candidates(self, mention: Span) -> Iterable[Candidate]:
+    def get_candidates(self, mention: Span) -> Iterable[InMemoryCandidate]:
-        return self.get_alias_candidates(mention.text)  # type: ignore
+        return self._get_alias_candidates(mention.text)  # type: ignore
 
-    def get_alias_candidates(self, str alias) -> Iterable[Candidate]:
+    def _get_alias_candidates(self, str alias) -> Iterable[InMemoryCandidate]:
         """
         Return candidate entities for an alias. Each candidate defines the entity, the original alias,
         and the prior probability of that alias resolving to that entity.
@@ -241,14 +241,18 @@ cdef class InMemoryLookupKB(KnowledgeBase):
         alias_index = <int64_t>self._alias_index.get(alias_hash)
         alias_entry = self._aliases_table[alias_index]
 
-        return [Candidate(kb=self,
+        return [
-                          entity_hash=self._entries[entry_index].entity_hash,
+            InMemoryCandidate(
-                          entity_freq=self._entries[entry_index].freq,
+                kb=self,
-                          entity_vector=self._vectors_table[self._entries[entry_index].vector_index],
+                entity_hash=self._entries[entry_index].entity_hash,
-                          alias_hash=alias_hash,
+                alias_hash=alias_hash,
-                          prior_prob=prior_prob)
+                entity_vector=self._vectors_table[self._entries[entry_index].vector_index],
-                for (entry_index, prior_prob) in zip(alias_entry.entry_indices, alias_entry.probs)
+                prior_prob=prior_prob,
-                if entry_index != 0]
+                entity_freq=self._entries[entry_index].freq
+            )
+            for (entry_index, prior_prob) in zip(alias_entry.entry_indices, alias_entry.probs)
+            if entry_index != 0
+        ]
 
     def get_vector(self, str entity):
         cdef hash_t entity_hash = self.vocab.strings[entity]
@@ -279,6 +283,9 @@ cdef class InMemoryLookupKB(KnowledgeBase):
 
         return 0.0
 
+    def supports_prior_probs(self) -> bool:
+        return True
+
     def to_bytes(self, **kwargs):
         """Serialize the current state to a binary string.
         """

spacy/ml/models/entity_linker.py

@@ -6,7 +6,7 @@ from thinc.api import Model, Maxout, Linear, tuplify, Ragged
 
 from ...util import registry
 from ...kb import KnowledgeBase, InMemoryLookupKB
-from ...kb import Candidate, get_candidates, get_candidates_batch
+from ...kb import Candidate
 from ...vocab import Vocab
 from ...tokens import Span, Doc
 from ..extract_spans import extract_spans
@@ -117,3 +117,25 @@ def create_candidates_batch() -> Callable[
     [KnowledgeBase, Iterable[Span]], Iterable[Iterable[Candidate]]
 ]:
     return get_candidates_batch
+
+
+def get_candidates(kb: KnowledgeBase, mention: Span) -> Iterable[Candidate]:
+    """
+    Return candidate entities for a given mention and fetching appropriate entries from the index.
+    kb (KnowledgeBase): Knowledge base to query.
+    mention (Span): Entity mention for which to identify candidates.
+    RETURNS (Iterable[Candidate]): Identified candidates.
+    """
+    return kb.get_candidates(mention)
+
+
+def get_candidates_batch(
+    kb: KnowledgeBase, mentions: Iterable[Span]
+) -> Iterable[Iterable[Candidate]]:
+    """
+    Return candidate entities for the given mentions and fetching appropriate entries from the index.
+    kb (KnowledgeBase): Knowledge base to query.
+    mentions (Iterable[Span]): Entity mentions for which to identify candidates.
+    RETURNS (Iterable[Iterable[Candidate]]): Identified candidates.
+    """
+    return kb.get_candidates_batch(mentions)

spacy/pipeline/entity_linker.py

@@ -1,5 +1,5 @@
-from typing import Optional, Iterable, Callable, Dict, Sequence, Union, List, Any
+import warnings
-from typing import cast
+from typing import Optional, Iterable, Callable, Dict, Sequence, Union, List, Any, cast
 from numpy import dtype
 from thinc.types import Floats1d, Floats2d, Ints1d, Ragged
 from pathlib import Path
@@ -10,14 +10,13 @@ from thinc.api import CosineDistance, Model, Optimizer, Config
 from thinc.api import set_dropout_rate
 
 from ..kb import KnowledgeBase, Candidate
-from ..ml import empty_kb
 from ..tokens import Doc, Span
 from .pipe import deserialize_config
 from .trainable_pipe import TrainablePipe
 from ..language import Language
 from ..vocab import Vocab
 from ..training import Example, validate_examples, validate_get_examples
-from ..errors import Errors
+from ..errors import Errors, Warnings
 from ..util import SimpleFrozenList, registry
 from .. import util
 from ..scorer import Scorer
@@ -240,6 +239,8 @@ class EntityLinker(TrainablePipe):
 
         if candidates_batch_size < 1:
             raise ValueError(Errors.E1044)
+        if self.incl_prior and not self.kb.supports_prior_probs:
+            warnings.warn(Warnings.W401)
 
     def set_kb(self, kb_loader: Callable[[Vocab], KnowledgeBase]):
         """Define the KB of this pipe by providing a function that will
@@ -522,18 +523,19 @@ class EntityLinker(TrainablePipe):
                             )
                         elif len(candidates) == 1 and self.threshold is None:
                             # shortcut for efficiency reasons: take the 1 candidate
-                            final_kb_ids.append(candidates[0].entity_)
+                            final_kb_ids.append(candidates[0].entity_id_)
                             self._add_activations(
                                 doc_scores=doc_scores,
                                 doc_ents=doc_ents,
                                 scores=[1.0],
-                                ents=[candidates[0].entity_],
+                                ents=[candidates[0].entity_id],
                             )
                         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 self.incl_prior and self.kb.supports_prior_probs:
-                            if not self.incl_prior:
+                                prior_probs = xp.asarray([c.prior_prob for c in candidates])  # type: ignore
+                            else:
                                 prior_probs = xp.asarray([0.0 for _ in candidates])
                             scores = prior_probs
                             # add in similarity from the context
@@ -557,7 +559,7 @@ class EntityLinker(TrainablePipe):
                                     raise ValueError(Errors.E161)
                                 scores = prior_probs + sims - (prior_probs * sims)
                             final_kb_ids.append(
-                                candidates[scores.argmax().item()].entity_
+                                candidates[scores.argmax().item()].entity_id_
                                 if self.threshold is None
                                 or scores.max() >= self.threshold
                                 else EntityLinker.NIL
@@ -566,7 +568,7 @@ class EntityLinker(TrainablePipe):
                                 doc_scores=doc_scores,
                                 doc_ents=doc_ents,
                                 scores=scores,
-                                ents=[c.entity for c in candidates],
+                                ents=[c.entity_id for c in candidates],
                             )
             self._add_doc_activations(
                 docs_scores=docs_scores,

spacy/tests/pipeline/test_entity_linker.py

@@ -7,10 +7,10 @@ from thinc.types import Ragged
 from spacy import registry, util
 from spacy.attrs import ENT_KB_ID
 from spacy.compat import pickle
-from spacy.kb import Candidate, InMemoryLookupKB, get_candidates, KnowledgeBase
+from spacy.kb import Candidate, InMemoryLookupKB, KnowledgeBase
 from spacy.lang.en import English
 from spacy.ml import load_kb
-from spacy.ml.models.entity_linker import build_span_maker
+from spacy.ml.models.entity_linker import build_span_maker, get_candidates
 from spacy.pipeline import EntityLinker, TrainablePipe
 from spacy.pipeline.tok2vec import DEFAULT_TOK2VEC_MODEL
 from spacy.scorer import Scorer
@@ -465,16 +465,17 @@ def test_candidate_generation(nlp):
     mykb.add_alias(alias="adam", entities=["Q2"], probabilities=[0.9])
 
     # test the size of the relevant candidates
+    adam_ent_cands = get_candidates(mykb, adam_ent)
     assert len(get_candidates(mykb, douglas_ent)) == 2
-    assert len(get_candidates(mykb, adam_ent)) == 1
+    assert len(adam_ent_cands) == 1
     assert len(get_candidates(mykb, Adam_ent)) == 0  # default case sensitive
     assert len(get_candidates(mykb, shrubbery_ent)) == 0
 
     # test the content of the candidates
-    assert get_candidates(mykb, adam_ent)[0].entity_ == "Q2"
+    assert adam_ent_cands[0].entity_id_ == "Q2"
-    assert get_candidates(mykb, adam_ent)[0].alias_ == "adam"
+    assert adam_ent_cands[0].alias == "adam"
-    assert_almost_equal(get_candidates(mykb, adam_ent)[0].entity_freq, 12)
+    assert_almost_equal(adam_ent_cands[0].entity_freq, 12)
-    assert_almost_equal(get_candidates(mykb, adam_ent)[0].prior_prob, 0.9)
+    assert_almost_equal(adam_ent_cands[0].prior_prob, 0.9)
 
 
 def test_el_pipe_configuration(nlp):
@@ -502,7 +503,7 @@ def test_el_pipe_configuration(nlp):
     assert doc[2].ent_kb_id_ == "Q2"
 
     def get_lowercased_candidates(kb, span):
-        return kb.get_alias_candidates(span.text.lower())
+        return kb._get_alias_candidates(span.text.lower())
 
     def get_lowercased_candidates_batch(kb, spans):
         return [get_lowercased_candidates(kb, span) for span in spans]
@@ -561,24 +562,22 @@ def test_vocab_serialization(nlp):
     mykb.add_alias(alias="douglas", entities=["Q2", "Q3"], probabilities=[0.4, 0.1])
     adam_hash = mykb.add_alias(alias="adam", entities=["Q2"], probabilities=[0.9])
 
-    candidates = mykb.get_alias_candidates("adam")
+    candidates = mykb._get_alias_candidates("adam")
     assert len(candidates) == 1
-    assert candidates[0].entity == q2_hash
+    assert candidates[0].entity_id == q2_hash
-    assert candidates[0].entity_ == "Q2"
+    assert candidates[0].entity_id_ == "Q2"
-    assert candidates[0].alias == adam_hash
+    assert candidates[0].alias == "adam"
-    assert candidates[0].alias_ == "adam"
 
     with make_tempdir() as d:
         mykb.to_disk(d / "kb")
         kb_new_vocab = InMemoryLookupKB(Vocab(), entity_vector_length=1)
         kb_new_vocab.from_disk(d / "kb")
 
-        candidates = kb_new_vocab.get_alias_candidates("adam")
+        candidates = kb_new_vocab._get_alias_candidates("adam")
         assert len(candidates) == 1
-        assert candidates[0].entity == q2_hash
+        assert candidates[0].entity_id == q2_hash
-        assert candidates[0].entity_ == "Q2"
+        assert candidates[0].entity_id_ == "Q2"
-        assert candidates[0].alias == adam_hash
+        assert candidates[0].alias == "adam"
-        assert candidates[0].alias_ == "adam"
 
         assert kb_new_vocab.get_vector("Q2") == [2]
         assert_almost_equal(kb_new_vocab.get_prior_prob("Q2", "douglas"), 0.4)
@@ -598,20 +597,20 @@ def test_append_alias(nlp):
     mykb.add_alias(alias="adam", entities=["Q2"], probabilities=[0.9])
 
     # test the size of the relevant candidates
-    assert len(mykb.get_alias_candidates("douglas")) == 2
+    assert len(mykb._get_alias_candidates("douglas")) == 2
 
     # append an alias
     mykb.append_alias(alias="douglas", entity="Q1", prior_prob=0.2)
 
     # test the size of the relevant candidates has been incremented
-    assert len(mykb.get_alias_candidates("douglas")) == 3
+    assert len(mykb._get_alias_candidates("douglas")) == 3
 
     # append the same alias-entity pair again should not work (will throw a warning)
     with pytest.warns(UserWarning):
         mykb.append_alias(alias="douglas", entity="Q1", prior_prob=0.3)
 
     # test the size of the relevant candidates remained unchanged
-    assert len(mykb.get_alias_candidates("douglas")) == 3
+    assert len(mykb._get_alias_candidates("douglas")) == 3
 
 
 @pytest.mark.filterwarnings("ignore:\\[W036")
@@ -908,11 +907,11 @@ def test_kb_to_bytes():
     assert kb_2.contains_alias("Russ Cochran")
     assert kb_1.get_size_aliases() == kb_2.get_size_aliases()
     assert kb_1.get_alias_strings() == kb_2.get_alias_strings()
-    assert len(kb_1.get_alias_candidates("Russ Cochran")) == len(
+    assert len(kb_1._get_alias_candidates("Russ Cochran")) == len(
-        kb_2.get_alias_candidates("Russ Cochran")
+        kb_2._get_alias_candidates("Russ Cochran")
     )
-    assert len(kb_1.get_alias_candidates("Randomness")) == len(
+    assert len(kb_1._get_alias_candidates("Randomness")) == len(
-        kb_2.get_alias_candidates("Randomness")
+        kb_2._get_alias_candidates("Randomness")
     )
 
 

spacy/tests/serialize/test_serialize_kb.py

@@ -66,19 +66,21 @@ def _check_kb(kb):
         assert alias_string not in kb.get_alias_strings()
 
     # check candidates & probabilities
-    candidates = sorted(kb.get_alias_candidates("double07"), key=lambda x: x.entity_)
+    candidates = sorted(
+        kb._get_alias_candidates("double07"), key=lambda x: x.entity_id_
+    )
     assert len(candidates) == 2
 
-    assert candidates[0].entity_ == "Q007"
+    assert candidates[0].entity_id_ == "Q007"
     assert 6.999 < candidates[0].entity_freq < 7.01
     assert candidates[0].entity_vector == [0, 0, 7]
-    assert candidates[0].alias_ == "double07"
+    assert candidates[0].alias == "double07"
     assert 0.899 < candidates[0].prior_prob < 0.901
 
-    assert candidates[1].entity_ == "Q17"
+    assert candidates[1].entity_id_ == "Q17"
     assert 1.99 < candidates[1].entity_freq < 2.01
     assert candidates[1].entity_vector == [7, 1, 0]
-    assert candidates[1].alias_ == "double07"
+    assert candidates[1].alias == "double07"
     assert 0.099 < candidates[1].prior_prob < 0.101
 
 

website/docs/api/inmemorylookupkb.mdx

@@ -10,9 +10,9 @@ version: 3.5
 
 The `InMemoryLookupKB` class inherits from [`KnowledgeBase`](/api/kb) and
 implements all of its methods. It stores all KB data in-memory and generates
-[`Candidate`](/api/kb#candidate) objects by exactly matching mentions with
+[`InMemoryCandidate`](/api/kb#candidate) objects by exactly matching mentions
-entity names. It's highly optimized for both a low memory footprint and speed of
+with entity names. It's highly optimized for both a low memory footprint and
-retrieval.
+speed of retrieval.
 
 ## InMemoryLookupKB.\_\_init\_\_ {id="init",tag="method"}
 
@@ -156,7 +156,7 @@ Get a list of all aliases in the knowledge base.
 ## InMemoryLookupKB.get_candidates {id="get_candidates",tag="method"}
 
 Given a certain textual mention as input, retrieve a list of candidate entities
-of type [`Candidate`](/api/kb#candidate). Wraps
+of type [`InMemoryCandidate`](/api/kb#candidate). Wraps
 [`get_alias_candidates()`](/api/inmemorylookupkb#get_alias_candidates).
 
 > #### Example
@@ -168,10 +168,10 @@ of type [`Candidate`](/api/kb#candidate). Wraps
 > candidates = kb.get_candidates(doc[0:2])
 > ```
 
-| Name        | Description                                                          |
+| Name        | Description                                                                          |
-| ----------- | -------------------------------------------------------------------- |
+| ----------- | ------------------------------------------------------------------------------------ |
-| `mention`   | The textual mention or alias. ~~Span~~                               |
+| `mention`   | The textual mention or alias. ~~Span~~                                               |
-| **RETURNS** | An iterable of relevant `Candidate` objects. ~~Iterable[Candidate]~~ |
+| **RETURNS** | An iterable of relevant `InMemoryCandidate` objects. ~~Iterable[InMemoryCandidate]~~ |
 
 ## InMemoryLookupKB.get_candidates_batch {id="get_candidates_batch",tag="method"}
 
@@ -194,26 +194,10 @@ to you.
 > candidates = kb.get_candidates((doc[0:2], doc[3:]))
 > ```
 
-| Name        | Description                                                                                  |
+| Name        | Description                                                                                                  |
-| ----------- | -------------------------------------------------------------------------------------------- |
+| ----------- | ------------------------------------------------------------------------------------------------------------ |
-| `mentions`  | The textual mention or alias. ~~Iterable[Span]~~                                             |
+| `mentions`  | The textual mentions. ~~Iterable[Span]~~                                                                     |
-| **RETURNS** | An iterable of iterable with relevant `Candidate` objects. ~~Iterable[Iterable[Candidate]]~~ |
+| **RETURNS** | An iterable of iterable with relevant `InMemoryCandidate` objects. ~~Iterable[Iterable[InMemoryCandidate]]~~ |
-
-## InMemoryLookupKB.get_alias_candidates {id="get_alias_candidates",tag="method"}
-
-Given a certain textual mention as input, retrieve a list of candidate entities
-of type [`Candidate`](/api/kb#candidate).
-
-> #### Example
->
-> ```python
-> candidates = kb.get_alias_candidates("Douglas")
-> ```
-
-| Name        | Description                                                   |
-| ----------- | ------------------------------------------------------------- |
-| `alias`     | The textual mention or alias. ~~str~~                         |
-| **RETURNS** | The list of relevant `Candidate` objects. ~~List[Candidate]~~ |
 
 ## InMemoryLookupKB.get_vector {id="get_vector",tag="method"}
 

website/docs/api/kb.mdx

@@ -103,23 +103,6 @@ to you.
 | `mentions`  | The textual mention or alias. ~~Iterable[Span]~~                                             |
 | **RETURNS** | An iterable of iterable with relevant `Candidate` objects. ~~Iterable[Iterable[Candidate]]~~ |
 
-## KnowledgeBase.get_alias_candidates {id="get_alias_candidates",tag="method"}
-
-<Infobox variant="warning">
-  This method is _not_ available from spaCy 3.5 onwards.
-</Infobox>
-
-From spaCy 3.5 on `KnowledgeBase` is an abstract class (with
-[`InMemoryLookupKB`](/api/inmemorylookupkb) being a drop-in replacement) to
-allow more flexibility in customizing knowledge bases. Some of its methods were
-moved to [`InMemoryLookupKB`](/api/inmemorylookupkb) during this refactoring,
-one of those being `get_alias_candidates()`. This method is now available as
-[`InMemoryLookupKB.get_alias_candidates()`](/api/inmemorylookupkb#get_alias_candidates).
-Note:
-[`InMemoryLookupKB.get_candidates()`](/api/inmemorylookupkb#get_candidates)
-defaults to
-[`InMemoryLookupKB.get_alias_candidates()`](/api/inmemorylookupkb#get_alias_candidates).
-
 ## KnowledgeBase.get_vector {id="get_vector",tag="method"}
 
 Given a certain entity ID, retrieve its pretrained entity vector.
@@ -190,25 +173,27 @@ Restore the state of the knowledge base from a given directory. Note that the
 | `exclude`   | List of components to exclude. ~~Iterable[str]~~                                                |
 | **RETURNS** | The modified `KnowledgeBase` object. ~~KnowledgeBase~~                                          |
 
-## Candidate {id="candidate",tag="class"}
+## InMemoryCandidate {id="candidate",tag="class"}
 
-A `Candidate` object refers to a textual mention (alias) that may or may not be
+An `InMemoryCandidate` object refers to a textual mention (alias) that may or
-resolved to a specific entity from a `KnowledgeBase`. This will be used as input
+may not be resolved to a specific entity from a `KnowledgeBase`. This will be
-for the entity linking algorithm which will disambiguate the various candidates
+used as input for the entity linking algorithm which will disambiguate the
-to the correct one. Each candidate `(alias, entity)` pair is assigned to a
+various candidates to the correct one. Each candidate `(alias, entity)` pair is
-certain prior probability.
+assigned to a certain prior probability.
 
-### Candidate.\_\_init\_\_ {id="candidate-init",tag="method"}
+### InMemoryCandidate.\_\_init\_\_ {id="candidate-init",tag="method"}
 
-Construct a `Candidate` object. Usually this constructor is not called directly,
+Construct an `InMemoryCandidate` object. Usually this constructor is not called
-but instead these objects are returned by the `get_candidates` method of the
+directly, but instead these objects are returned by the `get_candidates` method
-[`entity_linker`](/api/entitylinker) pipe.
+of the [`entity_linker`](/api/entitylinker) pipe.
 
-> #### Example
+> #### Example```python
+>
+> from spacy.kb import InMemoryCandidate candidate = InMemoryCandidate(kb,
+> entity_hash, entity_freq, entity_vector, alias_hash, prior_prob)
+>
+> ```
 >
-> ```python
-> from spacy.kb import Candidate
-> candidate = Candidate(kb, entity_hash, entity_freq, entity_vector, alias_hash, prior_prob)
 > ```
 
 | Name          | Description                                                               |
@@ -216,10 +201,10 @@ but instead these objects are returned by the `get_candidates` method of the
 | `kb`          | The knowledge base that defined this candidate. ~~KnowledgeBase~~         |
 | `entity_hash` | The hash of the entity's KB ID. ~~int~~                                   |
 | `entity_freq` | The entity frequency as recorded in the KB. ~~float~~                     |
-| `alias_hash`  | The hash of the textual mention or alias. ~~int~~                         |
+| `alias_hash`  | The hash of the entity alias. ~~int~~                                     |
 | `prior_prob`  | The prior probability of the `alias` referring to the `entity`. ~~float~~ |
 
-## Candidate attributes {id="candidate-attributes"}
+## InMemoryCandidate attributes {id="candidate-attributes"}
 
 | Name            | Description                                                              |
 | --------------- | ------------------------------------------------------------------------ |