spaCy/examples/training/train_parser.py
2017-10-27 03:55:04 +02:00

110 lines
3.4 KiB
Python

#!/usr/bin/env python
# coding: utf8
"""
Example of training spaCy dependency parser, starting off with an existing model
or a blank model.
For more details, see the documentation:
* Training: https://alpha.spacy.io/usage/training
* Dependency Parse: https://alpha.spacy.io/usage/linguistic-features#dependency-parse
Developed for: spaCy 2.0.0a18
Last updated for: spaCy 2.0.0a18
"""
from __future__ import unicode_literals, print_function
import plac
import random
from pathlib import Path
import spacy
from spacy.gold import GoldParse
from spacy.tokens import Doc
# training data
TRAIN_DATA = [
(
['They', 'trade', 'mortgage', '-', 'backed', 'securities', '.'],
[1, 1, 4, 4, 5, 1, 1],
['nsubj', 'ROOT', 'compound', 'punct', 'nmod', 'dobj', 'punct']
),
(
['I', 'like', 'London', 'and', 'Berlin', '.'],
[1, 1, 1, 2, 2, 1],
['nsubj', 'ROOT', 'dobj', 'cc', 'conj', 'punct']
)
]
@plac.annotations(
model=("Model name. Defaults to blank 'en' model.", "option", "m", str),
output_dir=("Optional output directory", "option", "o", Path),
n_iter=("Number of training iterations", "option", "n", int))
def main(model=None, output_dir=None, n_iter=1000):
"""Load the model, set up the pipeline and train the parser."""
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 parser to the pipeline if it doesn't exist
# nlp.create_pipe works for built-ins that are registered with spaCy
if 'parser' not in nlp.pipe_names:
parser = nlp.create_pipe('parser')
nlp.add_pipe(parser, first=True)
# otherwise, get it, so we can add labels to it
else:
parser = nlp.get_pipe('parser')
# add labels to the parser
for _, _, deps in TRAIN_DATA:
for dep in deps:
parser.add_label(dep)
# get names of other pipes to disable them during training
other_pipes = [pipe for pipe in nlp.pipe_names if pipe != 'parser']
with nlp.disable_pipes(*other_pipes): # only train parser
optimizer = nlp.begin_training(lambda: [])
for itn in range(n_iter):
random.shuffle(TRAIN_DATA)
losses = {}
for words, heads, deps in TRAIN_DATA:
doc = Doc(nlp.vocab, words=words)
gold = GoldParse(doc, heads=heads, deps=deps)
nlp.update([doc], [gold], sgd=optimizer, losses=losses)
print(losses)
# test the trained model
test_text = "I like securities."
doc = nlp(test_text)
print('Dependencies', [(t.text, t.dep_, t.head.text) for t in doc])
# save model to output directory
if output_dir is not None:
output_dir = Path(output_dir)
if not output_dir.exists():
output_dir.mkdir()
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)
doc = nlp2(test_text)
print('Dependencies', [(t.text, t.dep_, t.head.text) for t in doc])
if __name__ == '__main__':
plac.call(main)
# expected result:
# [
# ('I', 'nsubj', 'like'),
# ('like', 'ROOT', 'like'),
# ('securities', 'dobj', 'like'),
# ('.', 'punct', 'like')
# ]