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2026-07-13 12:37:18 +08:00

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3.1 KiB
Python

# -*- coding:utf-8 -*-
# Author: hankcs
# Date: 2022-09-28 13:31
import os
import sys
from typing import List, Union
import fasttext
from fasttext.FastText import _FastText
import hanlp
from hanlp.common.component import Component
from hanlp.utils.io_util import get_resource, stdout_redirected
from hanlp_common.io import load_json
from hanlp_common.reflection import classpath_of
from hanlp_common.structure import SerializableDict
class FastTextClassifier(Component):
def __init__(self) -> None:
super().__init__()
self._model: _FastText = None
self.config = SerializableDict({
'classpath': classpath_of(self),
'hanlp_version': hanlp.__version__,
})
def load(self, save_dir, model_path=None, **kwargs):
config_path = os.path.join(save_dir, 'config.json')
if os.path.isfile(config_path):
self.config: dict = load_json(config_path)
model_path = self.config.get('model_path', model_path)
else:
model_path = model_path or save_dir
self.config['model_path'] = model_path
filepath = get_resource(model_path)
with stdout_redirected(to=os.devnull, stdout=sys.stderr):
self._model = fasttext.load_model(filepath)
def predict(self, text: Union[str, List[str]], topk=False, prob=False, max_len=None, **kwargs):
"""
Classify text.
Args:
text: A document or a list of documents.
topk: ``True`` or ``int`` to return the top-k labels.
prob: Return also probabilities.
max_len: Strip long document into ``max_len`` characters for faster prediction.
**kwargs: Not used
Returns:
Classification results.
"""
num_labels = len(self._model.get_labels())
flat = isinstance(text, str)
if flat:
text = [text]
if not isinstance(topk, list):
topk = [topk] * len(text)
if not isinstance(prob, list):
prob = [prob] * len(text)
if max_len:
text = [x[:max_len] for x in text]
text = [x.replace('\n', ' ') for x in text]
batch_labels, batch_probs = self._model.predict(text, k=num_labels)
results = []
for labels, probs, k, p in zip(batch_labels, batch_probs, topk, prob):
labels = [self._strip_prefix(x) for x in labels]
if k is False:
labels = labels[0]
elif k is True:
pass
elif k:
labels = labels[:k]
if p:
probs = probs.tolist()
if k is False:
result = labels, probs[0]
else:
result = dict(zip(labels, probs))
else:
result = labels
results.append(result)
if flat:
results = results[0]
return results
@property
def labels(self):
return [self._strip_prefix(x) for x in self._model.get_labels()]
@staticmethod
def _strip_prefix(label: str):
return label[len('__label__'):]