spaCy/spacy/tests/pipeline/test_textcat.py

import pytest
import random
import numpy.random

from spacy import util
from spacy.lang.en import English
from spacy.language import Language
from spacy.pipeline import TextCategorizer
from spacy.tokens import Doc
from spacy.gold import GoldParse
from spacy.util import fix_random_seed

from ..util import make_tempdir
from spacy.pipeline.defaults import default_tok2vec

TRAIN_DATA = [
    ("I'm so happy.", {"cats": {"POSITIVE": 1.0, "NEGATIVE": 0.0}}),
    ("I'm so angry", {"cats": {"POSITIVE": 0.0, "NEGATIVE": 1.0}}),
]


@pytest.mark.skip(reason="Test is flakey when run with others")
def test_simple_train():
    nlp = Language()
    nlp.add_pipe(nlp.create_pipe("textcat"))
    nlp.get_pipe("textcat").add_label("answer")
    nlp.begin_training()
    for i in range(5):
        for text, answer in [
            ("aaaa", 1.0),
            ("bbbb", 0),
            ("aa", 1.0),
            ("bbbbbbbbb", 0.0),
            ("aaaaaa", 1),
        ]:
            nlp.update((text, {"cats": {"answer": answer}}))
    doc = nlp("aaa")
    assert "answer" in doc.cats
    assert doc.cats["answer"] >= 0.5


@pytest.mark.skip(reason="Test is flakey when run with others")
def test_textcat_learns_multilabel():
    random.seed(5)
    numpy.random.seed(5)
    docs = []
    nlp = Language()
    letters = ["a", "b", "c"]
    for w1 in letters:
        for w2 in letters:
            cats = {letter: float(w2 == letter) for letter in letters}
            docs.append((Doc(nlp.vocab, words=["d"] * 3 + [w1, w2] + ["d"] * 3), cats))
    random.shuffle(docs)
    model = TextCategorizer(nlp.vocab, width=8)
    for letter in letters:
        model.add_label(letter)
    optimizer = model.begin_training()
    for i in range(30):
        losses = {}
        Ys = [GoldParse(doc, cats=cats) for doc, cats in docs]
        Xs = [doc for doc, cats in docs]
        model.update(Xs, Ys, sgd=optimizer, losses=losses)
        random.shuffle(docs)
    for w1 in letters:
        for w2 in letters:
            doc = Doc(nlp.vocab, words=["d"] * 3 + [w1, w2] + ["d"] * 3)
            truth = {letter: w2 == letter for letter in letters}
            model(doc)
            for cat, score in doc.cats.items():
                if not truth[cat]:
                    assert score < 0.5
                else:
                    assert score > 0.5


def test_label_types():
    nlp = Language()
    nlp.add_pipe(nlp.create_pipe("textcat"))
    nlp.get_pipe("textcat").add_label("answer")
    with pytest.raises(ValueError):
        nlp.get_pipe("textcat").add_label(9)


def test_overfitting_IO():
    # Simple test to try and quickly overfit the textcat component - ensuring the ML models work correctly
    fix_random_seed(0)
    nlp = English()
    textcat = nlp.create_pipe("textcat")
    for _, annotations in TRAIN_DATA:
        for label, value in annotations.get("cats").items():
            textcat.add_label(label)
    nlp.add_pipe(textcat)
    optimizer = nlp.begin_training()

    for i in range(50):
        losses = {}
        nlp.update(TRAIN_DATA, sgd=optimizer, losses=losses)
    assert losses["textcat"] < 0.01

    # test the trained model
    test_text = "I am happy."
    doc = nlp(test_text)
    cats = doc.cats
    # note that by default, exclusive_classes = false so we need a bigger error margin
    assert cats["POSITIVE"] > 0.9
    assert cats["POSITIVE"] + cats["NEGATIVE"] == pytest.approx(1.0, 0.1)

    # 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(test_text)
        cats2 = doc2.cats
        assert cats2["POSITIVE"] > 0.9
        assert cats2["POSITIVE"] + cats2["NEGATIVE"] == pytest.approx(1.0, 0.1)


# fmt: off
@pytest.mark.parametrize(
    "textcat_config",
    [
        {"@architectures": "spacy.TextCatBOW.v1", "exclusive_classes": False, "ngram_size": 1, "no_output_layer": False},
        {"@architectures": "spacy.TextCatBOW.v1", "exclusive_classes": True, "ngram_size": 4, "no_output_layer": False},
        {"@architectures": "spacy.TextCatBOW.v1", "exclusive_classes": False, "ngram_size": 3, "no_output_layer": True},
        {"@architectures": "spacy.TextCatBOW.v1", "exclusive_classes": True, "ngram_size": 2, "no_output_layer": True},
        {"@architectures": "spacy.TextCat.v1", "exclusive_classes": False, "ngram_size": 1, "pretrained_vectors": False, "width": 64, "conv_depth": 2, "embed_size": 2000, "window_size": 2, "dropout": None},
        {"@architectures": "spacy.TextCat.v1", "exclusive_classes": True, "ngram_size": 5, "pretrained_vectors": False, "width": 128, "conv_depth": 2, "embed_size": 2000, "window_size": 1, "dropout": None},
        {"@architectures": "spacy.TextCat.v1", "exclusive_classes": True, "ngram_size": 2, "pretrained_vectors": False, "width": 32, "conv_depth": 3, "embed_size": 500, "window_size": 3, "dropout": None},
        {"@architectures": "spacy.TextCatCNN.v1", "tok2vec": default_tok2vec(), "exclusive_classes": True},
        {"@architectures": "spacy.TextCatCNN.v1", "tok2vec": default_tok2vec(), "exclusive_classes": False},
    ],
)
# fmt: on
def test_textcat_configs(textcat_config):
    pipe_config = {"model": textcat_config}
    nlp = English()
    textcat = nlp.create_pipe("textcat", pipe_config)
    for _, annotations in TRAIN_DATA:
        for label, value in annotations.get("cats").items():
            textcat.add_label(label)
    nlp.add_pipe(textcat)
    optimizer = nlp.begin_training()
    for i in range(5):
        losses = {}
        nlp.update(TRAIN_DATA, sgd=optimizer, losses=losses)