spaCy/spacy/tests/pipeline/test_lemmatizer.py

import pytest
from spacy import util, registry
from spacy.lang.en import English
from spacy.lookups import Lookups

from ..util import make_tempdir


@pytest.fixture
def nlp():
    return English()


@pytest.fixture
def lemmatizer(nlp):
    @registry.misc("cope_lookups")
    def cope_lookups():
        lookups = Lookups()
        lookups.add_table("lemma_lookup", {"cope": "cope"})
        lookups.add_table("lemma_index", {"verb": ("cope", "cop")})
        lookups.add_table("lemma_exc", {"verb": {"coping": ("cope",)}})
        lookups.add_table("lemma_rules", {"verb": [["ing", ""]]})
        return lookups

    lemmatizer = nlp.add_pipe(
        "lemmatizer", config={"mode": "rule", "lookups": {"@misc": "cope_lookups"}}
    )
    return lemmatizer


def test_lemmatizer_init(nlp):
    @registry.misc("cope_lookups")
    def cope_lookups():
        lookups = Lookups()
        lookups.add_table("lemma_lookup", {"cope": "cope"})
        lookups.add_table("lemma_index", {"verb": ("cope", "cop")})
        lookups.add_table("lemma_exc", {"verb": {"coping": ("cope",)}})
        lookups.add_table("lemma_rules", {"verb": [["ing", ""]]})
        return lookups

    lemmatizer = nlp.add_pipe(
        "lemmatizer", config={"mode": "lookup", "lookups": {"@misc": "cope_lookups"}}
    )
    assert isinstance(lemmatizer.lookups, Lookups)
    assert lemmatizer.mode == "lookup"
    # replace any tables from spacy-lookups-data
    lemmatizer.lookups = Lookups()
    doc = nlp("coping")
    # lookup with no tables sets text as lemma
    assert doc[0].lemma_ == "coping"

    nlp.remove_pipe("lemmatizer")

    @registry.misc("empty_lookups")
    def empty_lookups():
        return Lookups()

    with pytest.raises(ValueError):
        nlp.add_pipe(
            "lemmatizer",
            config={"mode": "lookup", "lookups": {"@misc": "empty_lookups"}},
        )


def test_lemmatizer_config(nlp, lemmatizer):
    doc = nlp.make_doc("coping")
    doc[0].pos_ = "VERB"
    assert doc[0].lemma_ == ""
    doc = lemmatizer(doc)
    assert doc[0].text == "coping"
    assert doc[0].lemma_ == "cope"

    doc = nlp.make_doc("coping")
    doc[0].pos_ = "VERB"
    assert doc[0].lemma_ == ""
    doc = lemmatizer(doc)
    assert doc[0].text == "coping"
    assert doc[0].lemma_ == "cope"


def test_lemmatizer_serialize(nlp, lemmatizer):
    @registry.misc("cope_lookups")
    def cope_lookups():
        lookups = Lookups()
        lookups.add_table("lemma_lookup", {"cope": "cope"})
        lookups.add_table("lemma_index", {"verb": ("cope", "cop")})
        lookups.add_table("lemma_exc", {"verb": {"coping": ("cope",)}})
        lookups.add_table("lemma_rules", {"verb": [["ing", ""]]})
        return lookups

    nlp2 = English()
    lemmatizer2 = nlp2.add_pipe(
        "lemmatizer", config={"mode": "rule", "lookups": {"@misc": "cope_lookups"}}
    )
    lemmatizer2.from_bytes(lemmatizer.to_bytes())
    assert lemmatizer.to_bytes() == lemmatizer2.to_bytes()
    assert lemmatizer.lookups.tables == lemmatizer2.lookups.tables

    # Also test the results are still the same after IO
    with make_tempdir() as tmp_dir:
        nlp.to_disk(tmp_dir)
        nlp2 = util.load_model_from_path(tmp_dir)
        doc2 = nlp2.make_doc("coping")
        doc2[0].pos_ = "VERB"
        assert doc2[0].lemma_ == ""
        doc2 = lemmatizer(doc2)
        assert doc2[0].text == "coping"
        assert doc2[0].lemma_ == "cope"