spaCy/spacy/lang/fr/lemmatizer.py
Adriane Boyd e962784531
Add Lemmatizer and simplify related components (#5848)
* Add Lemmatizer and simplify related components

* Add `Lemmatizer` pipe with `lookup` and `rule` modes using the
`Lookups` tables.
* Reduce `Tagger` to a simple tagger that sets `Token.tag` (no pos or lemma)
* Reduce `Morphology` to only keep track of morph tags (no tag map, lemmatizer,
or morph rules)
* Remove lemmatizer from `Vocab`
* Adjust many many tests

Differences:

* No default lookup lemmas
* No special treatment of TAG in `from_array` and similar required
* Easier to modify labels in a `Tagger`
* No extra strings added from morphology / tag map

* Fix test

* Initial fix for Lemmatizer config/serialization

* Adjust init test to be more generic

* Adjust init test to force empty Lookups

* Add simple cache to rule-based lemmatizer

* Convert language-specific lemmatizers

Convert language-specific lemmatizers to component lemmatizers. Remove
previous lemmatizer class.

* Fix French and Polish lemmatizers

* Remove outdated UPOS conversions

* Update Russian lemmatizer init in tests

* Add minimal init/run tests for custom lemmatizers

* Add option to overwrite existing lemmas

* Update mode setting, lookup loading, and caching

* Make `mode` an immutable property
* Only enforce strict `load_lookups` for known supported modes
* Move caching into individual `_lemmatize` methods

* Implement strict when lang is not found in lookups

* Fix tables/lookups in make_lemmatizer

* Reallow provided lookups and allow for stricter checks

* Add lookups asset to all Lemmatizer pipe tests

* Rename lookups in lemmatizer init test

* Clean up merge

* Refactor lookup table loading

* Add helper from `load_lemmatizer_lookups` that loads required and
optional lookups tables based on settings provided by a config.

Additional slight refactor of lookups:

* Add `Lookups.set_table` to set a table from a provided `Table`
* Reorder class definitions to be able to specify type as `Table`

* Move registry assets into test methods

* Refactor lookups tables config

Use class methods within `Lemmatizer` to provide the config for
particular modes and to load the lookups from a config.

* Add pipe and score to lemmatizer

* Simplify Tagger.score

* Add missing import

* Clean up imports and auto-format

* Remove unused kwarg

* Tidy up and auto-format

* Update docstrings for Lemmatizer

Update docstrings for Lemmatizer.

Additionally modify `is_base_form` API to take `Token` instead of
individual features.

* Update docstrings

* Remove tag map values from Tagger.add_label

* Update API docs

* Fix relative link in Lemmatizer API docs
2020-08-07 15:27:13 +02:00

88 lines
2.9 KiB
Python

from typing import List, Dict
from ...pipeline import Lemmatizer
from ...tokens import Token
class FrenchLemmatizer(Lemmatizer):
"""
French language lemmatizer applies the default rule based lemmatization
procedure with some modifications for better French language support.
The parts of speech 'ADV', 'PRON', 'DET', 'ADP' and 'AUX' are added to use
the rule-based lemmatization. As a last resort, the lemmatizer checks in
the lookup table.
"""
@classmethod
def get_lookups_config(cls, mode: str) -> Dict:
if mode == "rule":
return {
"required_tables": [
"lemma_lookup",
"lemma_rules",
"lemma_exc",
"lemma_index",
],
"optional_tables": [],
}
else:
return super().get_lookups_config(mode)
def rule_lemmatize(self, token: Token) -> List[str]:
cache_key = (token.orth, token.pos)
if cache_key in self.cache:
return self.cache[cache_key]
string = token.text
univ_pos = token.pos_.lower()
if univ_pos in ("", "eol", "space"):
return [string.lower()]
elif "lemma_rules" not in self.lookups or univ_pos not in (
"noun",
"verb",
"adj",
"adp",
"adv",
"aux",
"cconj",
"det",
"pron",
"punct",
"sconj",
):
return self.lookup_lemmatize(token)
index_table = self.lookups.get_table("lemma_index", {})
exc_table = self.lookups.get_table("lemma_exc", {})
rules_table = self.lookups.get_table("lemma_rules", {})
lookup_table = self.lookups.get_table("lemma_lookup", {})
index = index_table.get(univ_pos, {})
exceptions = exc_table.get(univ_pos, {})
rules = rules_table.get(univ_pos, [])
string = string.lower()
forms = []
if string in index:
forms.append(string)
self.cache[cache_key] = forms
return forms
forms.extend(exceptions.get(string, []))
oov_forms = []
if not forms:
for old, new in rules:
if string.endswith(old):
form = string[: len(string) - len(old)] + new
if not form:
pass
elif form in index or not form.isalpha():
forms.append(form)
else:
oov_forms.append(form)
if not forms:
forms.extend(oov_forms)
if not forms and string in lookup_table.keys():
forms.append(self.lookup_lemmatize(token)[0])
if not forms:
forms.append(string)
forms = list(set(forms))
self.cache[cache_key] = forms
return forms