spaCy/spacy/ml/models/textcat.py
Matthew Honnibal 5bebbf7550
Python 3.13 support (#13823)
In order to support Python 3.13, we had to migrate to Cython 3.0. This caused some tricky interaction with our Pydantic usage, because Cython 3 uses the from __future__ import annotations semantics, which causes type annotations to be saved as strings.

The end result is that we can't have Language.factory decorated functions in Cython modules anymore, as the Language.factory decorator expects to inspect the signature of the functions and build a Pydantic model. If the function is implemented in Cython, an error is raised because the type is not resolved.

To address this I've moved the factory functions into a new module, spacy.pipeline.factories. I've added __getattr__ importlib hooks to the previous locations, in case anyone was importing these functions directly. The change should have no backwards compatibility implications.

Along the way I've also refactored the registration of functions for the config. Previously these ran as import-time side-effects, using the registry decorator. I've created instead a new module spacy.registrations. When the registry is accessed it calls a function ensure_populated(), which cases the registrations to occur.

I've made a similar change to the Language.factory registrations in the new spacy.pipeline.factories module.

I want to remove these import-time side-effects so that we can speed up the loading time of the library, which can be especially painful on the CLI. I also find that I'm often working to track down the implementations of functions referenced by strings in the config. Having the registrations all happen in one place will make this easier.

With these changes I've fortunately avoided the need to migrate to Pydantic v2 properly --- we're still using the v1 compatibility shim. We might not be able to hold out forever though: Pydantic (reasonably) aren't actively supporting the v1 shims. I put a lot of work into v2 migration when investigating the 3.13 support, and it's definitely challenging. In any case, it's a relief that we don't have to do the v2 migration at the same time as the Cython 3.0/Python 3.13 support.
2025-05-22 13:47:21 +02:00

365 lines
12 KiB
Python

from functools import partial
from typing import List, Optional, Tuple, cast
from thinc.api import (
Dropout,
Gelu,
LayerNorm,
Linear,
Logistic,
Maxout,
Model,
ParametricAttention,
ParametricAttention_v2,
Relu,
Softmax,
SparseLinear,
SparseLinear_v2,
chain,
clone,
concatenate,
list2ragged,
reduce_first,
reduce_last,
reduce_max,
reduce_mean,
reduce_sum,
residual,
resizable,
softmax_activation,
with_cpu,
)
from thinc.layers.chain import init as init_chain
from thinc.layers.resizable import resize_linear_weighted, resize_model
from thinc.types import ArrayXd, Floats2d
from ...attrs import ORTH
from ...errors import Errors
from ...tokens import Doc
from ...util import registry
from ..extract_ngrams import extract_ngrams
from ..staticvectors import StaticVectors
from .tok2vec import get_tok2vec_width
NEG_VALUE = -5000
def build_simple_cnn_text_classifier(
tok2vec: Model, exclusive_classes: bool, nO: Optional[int] = None
) -> Model[List[Doc], Floats2d]:
"""
Build a simple CNN text classifier, given a token-to-vector model as inputs.
If exclusive_classes=True, a softmax non-linearity is applied, so that the
outputs sum to 1. If exclusive_classes=False, a logistic non-linearity
is applied instead, so that outputs are in the range [0, 1].
"""
return build_reduce_text_classifier(
tok2vec=tok2vec,
exclusive_classes=exclusive_classes,
use_reduce_first=False,
use_reduce_last=False,
use_reduce_max=False,
use_reduce_mean=True,
nO=nO,
)
def resize_and_set_ref(model, new_nO, resizable_layer):
resizable_layer = resize_model(resizable_layer, new_nO)
model.set_ref("output_layer", resizable_layer.layers[0])
model.set_dim("nO", new_nO, force=True)
return model
def build_bow_text_classifier(
exclusive_classes: bool,
ngram_size: int,
no_output_layer: bool,
nO: Optional[int] = None,
) -> Model[List[Doc], Floats2d]:
return _build_bow_text_classifier(
exclusive_classes=exclusive_classes,
ngram_size=ngram_size,
no_output_layer=no_output_layer,
nO=nO,
sparse_linear=SparseLinear(nO=nO),
)
def build_bow_text_classifier_v3(
exclusive_classes: bool,
ngram_size: int,
no_output_layer: bool,
length: int = 262144,
nO: Optional[int] = None,
) -> Model[List[Doc], Floats2d]:
if length < 1:
raise ValueError(Errors.E1056.format(length=length))
# Find k such that 2**(k-1) < length <= 2**k.
length = 2 ** (length - 1).bit_length()
return _build_bow_text_classifier(
exclusive_classes=exclusive_classes,
ngram_size=ngram_size,
no_output_layer=no_output_layer,
nO=nO,
sparse_linear=SparseLinear_v2(nO=nO, length=length),
)
def _build_bow_text_classifier(
exclusive_classes: bool,
ngram_size: int,
no_output_layer: bool,
sparse_linear: Model[Tuple[ArrayXd, ArrayXd, ArrayXd], ArrayXd],
nO: Optional[int] = None,
) -> Model[List[Doc], Floats2d]:
fill_defaults = {"b": 0, "W": 0}
with Model.define_operators({">>": chain}):
output_layer = None
if not no_output_layer:
fill_defaults["b"] = NEG_VALUE
output_layer = softmax_activation() if exclusive_classes else Logistic()
resizable_layer: Model[Floats2d, Floats2d] = resizable(
sparse_linear,
resize_layer=partial(resize_linear_weighted, fill_defaults=fill_defaults),
)
model = extract_ngrams(ngram_size, attr=ORTH) >> resizable_layer
model = with_cpu(model, model.ops)
if output_layer:
model = model >> with_cpu(output_layer, output_layer.ops)
if nO is not None:
model.set_dim("nO", cast(int, nO))
model.set_ref("output_layer", sparse_linear)
model.attrs["multi_label"] = not exclusive_classes
model.attrs["resize_output"] = partial(
resize_and_set_ref, resizable_layer=resizable_layer
)
return model
def build_text_classifier_v2(
tok2vec: Model[List[Doc], List[Floats2d]],
linear_model: Model[List[Doc], Floats2d],
nO: Optional[int] = None,
) -> Model[List[Doc], Floats2d]:
# TODO: build the model with _build_parametric_attention_with_residual_nonlinear
# in spaCy v4. We don't do this in spaCy v3 to preserve model
# compatibility.
exclusive_classes = not linear_model.attrs["multi_label"]
with Model.define_operators({">>": chain, "|": concatenate}):
width = tok2vec.maybe_get_dim("nO")
attention_layer = ParametricAttention(width)
maxout_layer = Maxout(nO=width, nI=width)
norm_layer = LayerNorm(nI=width)
cnn_model = (
tok2vec
>> list2ragged()
>> attention_layer
>> reduce_sum()
>> residual(maxout_layer >> norm_layer >> Dropout(0.0))
)
nO_double = nO * 2 if nO else None
if exclusive_classes:
output_layer = Softmax(nO=nO, nI=nO_double)
else:
output_layer = Linear(nO=nO, nI=nO_double) >> Logistic()
model = (linear_model | cnn_model) >> output_layer
model.set_ref("tok2vec", tok2vec)
if model.has_dim("nO") is not False and nO is not None:
model.set_dim("nO", cast(int, nO))
model.set_ref("output_layer", linear_model.get_ref("output_layer"))
model.set_ref("attention_layer", attention_layer)
model.set_ref("maxout_layer", maxout_layer)
model.set_ref("norm_layer", norm_layer)
model.attrs["multi_label"] = not exclusive_classes
model.init = init_ensemble_textcat # type: ignore[assignment]
return model
def init_ensemble_textcat(model, X, Y) -> Model:
# When tok2vec is lazily initialized, we need to initialize it before
# the rest of the chain to ensure that we can get its width.
tok2vec = model.get_ref("tok2vec")
tok2vec.initialize(X)
tok2vec_width = get_tok2vec_width(model)
model.get_ref("attention_layer").set_dim("nO", tok2vec_width)
model.get_ref("maxout_layer").set_dim("nO", tok2vec_width)
model.get_ref("maxout_layer").set_dim("nI", tok2vec_width)
model.get_ref("norm_layer").set_dim("nI", tok2vec_width)
model.get_ref("norm_layer").set_dim("nO", tok2vec_width)
init_chain(model, X, Y)
return model
def build_text_classifier_lowdata(
width: int, dropout: Optional[float], nO: Optional[int] = None
) -> Model[List[Doc], Floats2d]:
# Don't document this yet, I'm not sure it's right.
# Note, before v.3, this was the default if setting "low_data" and "pretrained_dims"
with Model.define_operators({">>": chain, "**": clone}):
model = (
StaticVectors(width)
>> list2ragged()
>> ParametricAttention(width)
>> reduce_sum()
>> residual(Relu(width, width)) ** 2
>> Linear(nO, width)
)
if dropout:
model = model >> Dropout(dropout)
model = model >> Logistic()
return model
def build_textcat_parametric_attention_v1(
tok2vec: Model[List[Doc], List[Floats2d]],
exclusive_classes: bool,
nO: Optional[int] = None,
) -> Model[List[Doc], Floats2d]:
width = tok2vec.maybe_get_dim("nO")
parametric_attention = _build_parametric_attention_with_residual_nonlinear(
tok2vec=tok2vec,
nonlinear_layer=Maxout(nI=width, nO=width),
key_transform=Gelu(nI=width, nO=width),
)
with Model.define_operators({">>": chain}):
if exclusive_classes:
output_layer = Softmax(nO=nO)
else:
output_layer = Linear(nO=nO) >> Logistic()
model = parametric_attention >> output_layer
if model.has_dim("nO") is not False and nO is not None:
model.set_dim("nO", cast(int, nO))
model.set_ref("output_layer", output_layer)
model.attrs["multi_label"] = not exclusive_classes
return model
def _build_parametric_attention_with_residual_nonlinear(
*,
tok2vec: Model[List[Doc], List[Floats2d]],
nonlinear_layer: Model[Floats2d, Floats2d],
key_transform: Optional[Model[Floats2d, Floats2d]] = None,
) -> Model[List[Doc], Floats2d]:
with Model.define_operators({">>": chain, "|": concatenate}):
width = tok2vec.maybe_get_dim("nO")
attention_layer = ParametricAttention_v2(nO=width, key_transform=key_transform)
norm_layer = LayerNorm(nI=width)
parametric_attention = (
tok2vec
>> list2ragged()
>> attention_layer
>> reduce_sum()
>> residual(nonlinear_layer >> norm_layer >> Dropout(0.0))
)
parametric_attention.init = _init_parametric_attention_with_residual_nonlinear
parametric_attention.set_ref("tok2vec", tok2vec)
parametric_attention.set_ref("attention_layer", attention_layer)
parametric_attention.set_ref("key_transform", key_transform)
parametric_attention.set_ref("nonlinear_layer", nonlinear_layer)
parametric_attention.set_ref("norm_layer", norm_layer)
return parametric_attention
def _init_parametric_attention_with_residual_nonlinear(model, X, Y) -> Model:
# When tok2vec is lazily initialized, we need to initialize it before
# the rest of the chain to ensure that we can get its width.
tok2vec = model.get_ref("tok2vec")
tok2vec.initialize(X)
tok2vec_width = get_tok2vec_width(model)
model.get_ref("attention_layer").set_dim("nO", tok2vec_width)
model.get_ref("key_transform").set_dim("nI", tok2vec_width)
model.get_ref("key_transform").set_dim("nO", tok2vec_width)
model.get_ref("nonlinear_layer").set_dim("nI", tok2vec_width)
model.get_ref("nonlinear_layer").set_dim("nO", tok2vec_width)
model.get_ref("norm_layer").set_dim("nI", tok2vec_width)
model.get_ref("norm_layer").set_dim("nO", tok2vec_width)
init_chain(model, X, Y)
return model
def build_reduce_text_classifier(
tok2vec: Model,
exclusive_classes: bool,
use_reduce_first: bool,
use_reduce_last: bool,
use_reduce_max: bool,
use_reduce_mean: bool,
nO: Optional[int] = None,
) -> Model[List[Doc], Floats2d]:
"""Build a model that classifies pooled `Doc` representations.
Pooling is performed using reductions. Reductions are concatenated when
multiple reductions are used.
tok2vec (Model): the tok2vec layer to pool over.
exclusive_classes (bool): Whether or not classes are mutually exclusive.
use_reduce_first (bool): Pool by using the hidden representation of the
first token of a `Doc`.
use_reduce_last (bool): Pool by using the hidden representation of the
last token of a `Doc`.
use_reduce_max (bool): Pool by taking the maximum values of the hidden
representations of a `Doc`.
use_reduce_mean (bool): Pool by taking the mean of all hidden
representations of a `Doc`.
nO (Optional[int]): Number of classes.
"""
fill_defaults = {"b": 0, "W": 0}
reductions = []
if use_reduce_first:
reductions.append(reduce_first())
if use_reduce_last:
reductions.append(reduce_last())
if use_reduce_max:
reductions.append(reduce_max())
if use_reduce_mean:
reductions.append(reduce_mean())
if not len(reductions):
raise ValueError(Errors.E1057)
with Model.define_operators({">>": chain}):
cnn = tok2vec >> list2ragged() >> concatenate(*reductions)
nO_tok2vec = tok2vec.maybe_get_dim("nO")
nI = nO_tok2vec * len(reductions) if nO_tok2vec is not None else None
if exclusive_classes:
output_layer = Softmax(nO=nO, nI=nI)
fill_defaults["b"] = NEG_VALUE
resizable_layer: Model = resizable(
output_layer,
resize_layer=partial(
resize_linear_weighted, fill_defaults=fill_defaults
),
)
model = cnn >> resizable_layer
else:
output_layer = Linear(nO=nO, nI=nI)
resizable_layer = resizable(
output_layer,
resize_layer=partial(
resize_linear_weighted, fill_defaults=fill_defaults
),
)
model = cnn >> resizable_layer >> Logistic()
model.set_ref("output_layer", output_layer)
model.attrs["resize_output"] = partial(
resize_and_set_ref,
resizable_layer=resizable_layer,
)
model.set_ref("tok2vec", tok2vec)
if nO is not None:
model.set_dim("nO", cast(int, nO))
model.attrs["multi_label"] = not exclusive_classes
return model