spaCy/spacy/tagger.pyx
2016-02-22 00:15:25 +01:00

373 lines
11 KiB
Cython

from __future__ import unicode_literals
import json
from os import path
from collections import defaultdict
from libc.string cimport memset
from cymem.cymem cimport Pool
from thinc.typedefs cimport atom_t, weight_t
from thinc.extra.eg cimport Example
from thinc.structs cimport ExampleC
from thinc.linear.avgtron cimport AveragedPerceptron
from thinc.linalg cimport VecVec
from .typedefs cimport attr_t
from .tokens.doc cimport Doc
from .attrs cimport TAG
from .parts_of_speech cimport NO_TAG, ADJ, ADV, ADP, CONJ, DET, NOUN, NUM, PRON
from .parts_of_speech cimport VERB, X, PUNCT, EOL, SPACE
from .attrs cimport *
from .util import get_package
cpdef enum:
P2_orth
P2_cluster
P2_shape
P2_prefix
P2_suffix
P2_pos
P2_lemma
P2_flags
P1_orth
P1_cluster
P1_shape
P1_prefix
P1_suffix
P1_pos
P1_lemma
P1_flags
W_orth
W_cluster
W_shape
W_prefix
W_suffix
W_pos
W_lemma
W_flags
N1_orth
N1_cluster
N1_shape
N1_prefix
N1_suffix
N1_pos
N1_lemma
N1_flags
N2_orth
N2_cluster
N2_shape
N2_prefix
N2_suffix
N2_pos
N2_lemma
N2_flags
N_CONTEXT_FIELDS
cdef class TaggerNeuralNet(NeuralNet):
def __init__(self, n_classes,
depth=1, hidden_width=100,
words_width=20, shape_width=5, suffix_width=5, tags_width=5,
learn_rate=0.1):
input_length = 5 * words_width + 5 * shape_width + 5 * suffix_width + 2 * tags_width
widths = [input_length] + [hidden_width] * depth + [n_classes]
vector_widths = [words_width, shape_width, suffix_width, tags_width]
slots = [0] * 5 + [1] * 5 + [2] * 5 + [3] * 2
NeuralNet.__init__(
self,
widths,
embed=(vector_widths, slots),
eta=learn_rate,
rho=1e-6,
update_step='sgd')
cdef void set_featuresC(self, ExampleC* eg, const TokenC* tokens, int i) except *:
eg.nr_feat = self.nr_feat
for j in range(eg.nr_feat):
eg.features[j].value = 1.0
eg.features[j].i = j
eg.features[0].key = tokens[i].lex.lower
eg.features[1].key = tokens[i-1].lex.lower
eg.features[2].key = tokens[i-2].lex.lower
eg.features[3].key = tokens[i+1].lex.lower
eg.features[4].key = tokens[i+2].lex.lower
eg.features[5].key = tokens[i].lex.shape
eg.features[6].key = tokens[i-1].lex.shape
eg.features[7].key = tokens[i-2].lex.shape
eg.features[8].key = tokens[i+1].lex.shape
eg.features[9].key = tokens[i+2].lex.shape
eg.features[10].key = tokens[i].lex.suffix
eg.features[11].key = tokens[i-1].lex.suffix
eg.features[12].key = tokens[i-2].lex.suffix
eg.features[13].key = tokens[i+1].lex.suffix
eg.features[14].key = tokens[i+2].lex.suffix
eg.features[15].key = tokens[i-2].tag
eg.features[16].key = tokens[i-1].tag
def end_training(self):
pass
def dump(self, loc):
pass
property nr_feat:
def __get__(self):
return 17
cdef class CharacterTagger(NeuralNet):
def __init__(self, n_classes,
depth=5, hidden_width=20,
chars_width=10,
words_width=20, shape_width=5, suffix_width=5, tags_width=20,
learn_rate=0.1):
input_length = 5 * chars_width * self.chars_per_word + 2 * tags_width
widths = [input_length] + [hidden_width] * depth + [n_classes]
vector_widths = [chars_width, tags_width]
slots = [0] * 5 * self.chars_per_word + [1] * 2
NeuralNet.__init__(
self,
widths,
embed=(vector_widths, slots),
eta=learn_rate,
rho=1e-6,
update_step='sgd')
cdef void set_featuresC(self, ExampleC* eg, const TokenC* tokens, object strings, int i) except *:
oov = '_' * self.chars_per_word
p2 = strings[i-2] if i >= 2 else oov
p1 = strings[i-1] if i >= 1 else oov
w = strings[i]
n1 = strings[i+1] if (i+1) < len(strings) else oov
n2 = strings[i+2] if (i+2) < len(strings) else oov
cdef int p = 0
cdef int c
cdef int chars_per_word = self.chars_per_word
cdef unicode string
for string in (p2, p1, w, n1, n2):
for c in range(chars_per_word / 2):
eg.features[p].i = p
eg.features[p].key = ord(string[c])
eg.features[p].value = 1.0 if string[c] != u'_' else 0.0
p += 1
eg.features[p].i = p
eg.features[p].key = ord(string[-(c+1)])
eg.features[p].value = 1.0 if string[-(c+1)] != u'_' else 0.0
p += 1
eg.features[p].key = tokens[i-1].tag
eg.features[p].value = 1.0
eg.features[p].i = p
p += 1
eg.features[p].key = tokens[i-2].tag
eg.features[p].value = 1.0
eg.features[p].i = p
eg.nr_feat = p+1
def end_training(self):
pass
def dump(self, loc):
pass
property nr_feat:
def __get__(self):
return self.chars_per_word * 5 + 2
property chars_per_word:
def __get__(self):
return 16
def _pad(word, nr_char):
if len(word) == nr_char:
pass
elif len(word) > nr_char:
split = nr_char / 2
word = word[:split] + word[-split:]
else:
word = word.ljust(nr_char, '_')
assert len(word) == nr_char, repr(word)
return word
cdef inline void _fill_from_token(atom_t* context, const TokenC* t) nogil:
context[0] = t.lex.lower
context[1] = t.lex.cluster
context[2] = t.lex.shape
context[3] = t.lex.prefix
context[4] = t.lex.suffix
context[5] = t.tag
context[6] = t.lemma
if t.lex.flags & (1 << IS_ALPHA):
context[7] = 1
elif t.lex.flags & (1 << IS_PUNCT):
context[7] = 2
elif t.lex.flags & (1 << LIKE_URL):
context[7] = 3
elif t.lex.flags & (1 << LIKE_NUM):
context[7] = 4
else:
context[7] = 0
cdef class Tagger:
"""A part-of-speech tagger for English"""
@classmethod
def read_config(cls, data_dir):
return json.load(open(path.join(data_dir, 'pos', 'config.json')))
@classmethod
def default_templates(cls):
return (
(W_orth,),
(P1_lemma, P1_pos),
(P2_lemma, P2_pos),
(N1_orth,),
(N2_orth,),
(W_suffix,),
(W_prefix,),
(P1_pos,),
(P2_pos,),
(P1_pos, P2_pos),
(P1_pos, W_orth),
(P1_suffix,),
(N1_suffix,),
(W_shape,),
(W_cluster,),
(N1_cluster,),
(N2_cluster,),
(P1_cluster,),
(P2_cluster,),
(W_flags,),
(N1_flags,),
(N2_flags,),
(P1_flags,),
(P2_flags,),
)
@classmethod
def blank(cls, vocab, templates, learn_rate=0.005):
model = CharacterTagger(vocab.morphology.n_tags, learn_rate=learn_rate)
return cls(vocab, model)
@classmethod
def load(cls, data_dir, vocab):
return cls.from_package(get_package(data_dir), vocab=vocab)
@classmethod
def from_package(cls, pkg, vocab):
# TODO: templates.json deprecated? not present in latest package
templates = cls.default_templates()
# templates = package.load_utf8(json.load,
# 'pos', 'templates.json',
# default=cls.default_templates())
model = TaggerNeuralNet()
if pkg.has_file('pos', 'model'):
model.load(pkg.file_path('pos', 'model'))
return cls(vocab, model)
def __init__(self, Vocab vocab, CharacterTagger model):
self.vocab = vocab
self.model = model
# TODO: Move this to tag map
self.freqs = {TAG: defaultdict(int)}
for tag in self.tag_names:
self.freqs[TAG][self.vocab.strings[tag]] = 1
self.freqs[TAG][0] = 1
@property
def tag_names(self):
return self.vocab.morphology.tag_names
def __reduce__(self):
return (self.__class__, (self.vocab, self.model), None, None)
def tag_from_strings(self, Doc tokens, object tag_strs):
cdef int i
for i in range(tokens.length):
self.vocab.morphology.assign_tag(&tokens.c[i], tag_strs[i])
tokens.is_tagged = True
tokens._py_tokens = [None] * tokens.length
def __call__(self, Doc tokens):
"""Apply the tagger, setting the POS tags onto the Doc object.
Args:
tokens (Doc): The tokens to be tagged.
"""
if tokens.length == 0:
return 0
cdef Pool mem = Pool()
cdef int i, tag
cdef Example eg = Example(nr_atom=N_CONTEXT_FIELDS,
widths=self.model.widths,
nr_class=self.vocab.morphology.n_tags,
nr_feat=self.model.nr_feat)
strings = [_pad(tok.text, self.model.chars_per_word) for tok in tokens]
for i in range(tokens.length):
eg.reset()
if tokens.c[i].pos == 0:
self.model.set_featuresC(&eg.c, tokens.c, strings, i)
self.model.predict_example(eg)
#self.model.set_scoresC(eg.c.scores,
# eg.c.features, eg.c.nr_feat)
guess = VecVec.arg_max_if_true(eg.c.scores, eg.c.is_valid, eg.c.nr_class)
self.vocab.morphology.assign_tag(&tokens.c[i], guess)
tokens.is_tagged = True
tokens._py_tokens = [None] * tokens.length
def pipe(self, stream, batch_size=1000, n_threads=2):
for doc in stream:
self(doc)
yield doc
def train(self, Doc tokens, object gold_tag_strs):
assert len(tokens) == len(gold_tag_strs)
for tag in gold_tag_strs:
if tag not in self.tag_names:
msg = ("Unrecognized gold tag: %s. tag_map.json must contain all"
"gold tags, to maintain coarse-grained mapping.")
raise ValueError(msg % tag)
golds = [self.tag_names.index(g) if g is not None else -1 for g in gold_tag_strs]
strings = [_pad(tok.text, self.model.chars_per_word) for tok in tokens]
cdef int correct = 0
cdef Pool mem = Pool()
cdef Example eg = Example(
nr_atom=N_CONTEXT_FIELDS,
nr_class=self.vocab.morphology.n_tags,
widths=self.model.widths,
nr_feat=self.model.nr_feat)
for i in range(tokens.length):
eg.reset()
self.model.set_featuresC(&eg.c, tokens.c, strings, i)
eg.costs = [golds[i] not in (j, -1) for j in range(eg.c.nr_class)]
self.model.train_example(eg)
#self.model.set_scoresC(eg.c.scores,
# eg.c.features, eg.c.nr_feat)
#
#self.model.updateC(&eg.c)
self.vocab.morphology.assign_tag(&tokens.c[i], eg.guess)
correct += eg.cost == 0
self.freqs[TAG][tokens.c[i].tag] += 1
tokens.is_tagged = True
tokens._py_tokens = [None] * tokens.length
return correct