def main(model=None, output_dir=None, n_iter=20, n_texts=2000, init_tok2vec=None, plot=False):
if output_dir is not None:
output_dir = Path(output_dir)
if not output_dir.exists():
output_dir.mkdir()
if model is not None:
nlp = spacy.load(model) # load existing spaCy model
print("Loaded model '%s'" % model)
else:
nlp = spacy.blank("en") # create blank Language class
print("Created blank 'en' model")
# add the text classifier to the pipeline if it doesn't exist
# nlp.create_pipe works for built-ins that are registered with spaCy
if "textcat" not in nlp.pipe_names:
textcat = nlp.create_pipe(
"textcat", config={"exclusive_classes": True, "architecture": "simple_cnn"}
)
nlp.add_pipe(textcat, last=True)
# otherwise, get it, so we can add labels to it
else:
textcat = nlp.get_pipe("textcat")
# add label to text classifier
textcat.add_label("POSITIVE")
textcat.add_label("NEGATIVE")
# load the IMDB dataset
print("Loading IMDB data...")
(train_texts, train_cats), (dev_texts, dev_cats) = load_data()
train_texts = train_texts[:n_texts]
train_cats = train_cats[:n_texts]
print(
"Using {} examples ({} training, {} evaluation)".format(
n_texts, len(train_texts), len(dev_texts)
)
)
train_data = list(zip(train_texts, [{"cats": cats} for cats in train_cats]))
dev_data = list(zip(dev_texts, [{"cats": cats} for cats in dev_cats]))
# get names of other pipes to disable them during training
pipe_exceptions = ["textcat", "trf_wordpiecer", "trf_tok2vec"]
other_pipes = [pipe for pipe in nlp.pipe_names if pipe not in pipe_exceptions]
with nlp.disable_pipes(*other_pipes): # only train textcat
optimizer = nlp.begin_training()
if init_tok2vec is not None:
with init_tok2vec.open("rb") as file_:
textcat.model.tok2vec.from_bytes(file_.read())
print("Training the model...")
print("{:^5}\t{:^5}\t{:^5}\t{:^5}".format("LOSS", "P", "R", "F"))
# Set-up the plotter:
if plot:
plotter = Plotter(
title='IMDB Text categorisation training',
ylabels=["Train-loss", "Dev-loss", "Precision", "Recall", "F-score"],
iterations=n_iter,
figsize=(8, 10))
batch_sizes = compounding(4.0, 32.0, 1.001)
for i in range(n_iter):
losses = {}
# batch up the examples using spaCy's minibatch
random.shuffle(train_data)
batches = minibatch(train_data, size=batch_sizes)
for batch in batches:
texts, annotations = zip(*batch)
nlp.update(texts, annotations, sgd=optimizer, drop=0.2, losses=losses)
with textcat.model.use_params(optimizer.averages):
# evaluate on the dev data split off in load_data()
scores = evaluate(nlp.tokenizer, textcat, dev_texts, dev_cats)
dev_losses = {}
random.shuffle(dev_data)
batches = minibatch(dev_data, size=batch_sizes)
for batch in batches:
texts, annotations = zip(*batch)
nlp.update(texts, annotations, sgd=None, losses=dev_losses)
print(
"{0:.3f}\t{1:.3f}\t{2:.3f}\t{3:.3f}".format( # print a simple table
losses["textcat"],
dev_losses["textcat"],
scores["textcat_p"],
scores["textcat_r"],
scores["textcat_f"],
)
)
# Update the plot:
if plot:
plotter.update(y=[
losses["textcat"],
dev_losses["textcat"],
scores["textcat_p"],
scores["textcat_r"],
scores["textcat_f"],
])
# test the trained model
test_text = "This movie sucked"
doc = nlp(test_text)
print(test_text, doc.cats)
if output_dir is not None:
with nlp.use_params(optimizer.averages):
nlp.to_disk(output_dir)
print("Saved model to", output_dir)
# test the saved model
print("Loading from", output_dir)
nlp2 = spacy.load(output_dir)
doc2 = nlp2(test_text)
print(test_text, doc2.cats)
# Keep showing the plot until the plotting window is closed.
if plot:
plotter.keep()
