huggingface-transformers - 如何在 Pytorch Lightning 中进行微调之前测试模型？
问题描述
在 Google Colab 上做事。
- 变压器：4.10.2
- 火炬闪电：1.2.7
import torch
from torch.utils.data import DataLoader
from transformers import BertJapaneseTokenizer, BertForSequenceClassification
import pytorch_lightning as pl
dataset_for_loader = [
{'data':torch.tensor([0,1]), 'labels':torch.tensor(0)},
{'data':torch.tensor([2,3]), 'labels':torch.tensor(1)},
{'data':torch.tensor([4,5]), 'labels':torch.tensor(2)},
{'data':torch.tensor([6,7]), 'labels':torch.tensor(3)},
]
loader = DataLoader(dataset_for_loader, batch_size=2)
for idx, batch in enumerate(loader):
print(f'# batch {idx}')
print(batch)
category_list = [
'dokujo-tsushin',
'it-life-hack',
'kaden-channel',
'livedoor-homme',
'movie-enter',
'peachy',
'smax',
'sports-watch',
'topic-news'
]
tokenizer = BertJapaneseTokenizer.from_pretrained(MODEL_NAME)
max_length = 128
dataset_for_loader = []
for label, category in enumerate(tqdm(category_list)):
# file ./text has lots of articles, categorized by category
# and they are just plain texts, whose content begins from forth line
for file in glob.glob(f'./text/{category}/{category}*'):
lines = open(file).read().splitlines()
text = '\n'.join(lines[3:])
encoding = tokenizer(
text,
max_length=max_length,
padding='max_length',
truncation=True
)
encoding['labels'] = label
encoding = { k: torch.tensor(v) for k, v in encoding.items() }
dataset_for_loader.append(encoding)
SEED=lambda:0.0
# random.shuffle(dataset_for_loader) # ランダムにシャッフル
random.shuffle(dataset_for_loader,SEED)
n = len(dataset_for_loader)
n_train = int(0.6*n)
n_val = int(0.2*n)
dataset_train = dataset_for_loader[:n_train]
dataset_val = dataset_for_loader[n_train:n_train+n_val]
dataset_test = dataset_for_loader[n_train+n_val:]
dataloader_train = DataLoader(
dataset_train, batch_size=32, shuffle=True
)
dataloader_val = DataLoader(dataset_val, batch_size=256)
dataloader_test = DataLoader(dataset_test, batch_size=256)
class BertForSequenceClassification_pl(pl.LightningModule):
def __init__(self, model_name, num_labels, lr):
super().__init__()
self.save_hyperparameters()
self.bert_sc = BertForSequenceClassification.from_pretrained(
model_name,
num_labels=num_labels
)
def training_step(self, batch, batch_idx):
output = self.bert_sc(**batch)
loss = output.loss
self.log('train_loss', loss)
return loss
def validation_step(self, batch, batch_idx):
output = self.bert_sc(**batch)
val_loss = output.loss
self.log('val_loss', val_loss)
def test_step(self, batch, batch_idx):
labels = batch.pop('labels')
output = self.bert_sc(**batch)
labels_predicted = output.logits.argmax(-1)
num_correct = ( labels_predicted == labels ).sum().item()
accuracy = num_correct/labels.size(0)
self.log('accuracy', accuracy)
def configure_optimizers(self):
return torch.optim.Adam(self.parameters(), lr=self.hparams.lr)
checkpoint = pl.callbacks.ModelCheckpoint(
monitor='val_loss',
mode='min',
save_top_k=1,
save_weights_only=True,
dirpath='model/',
)
trainer = pl.Trainer(
gpus=1,
max_epochs=10,
callbacks = [checkpoint]
)
model = BertForSequenceClassification_pl(
MODEL_NAME, num_labels=9, lr=1e-5
)
### (a) ###
# I think this is where I am doing fine-tuning
trainer.fit(model, dataloader_train, dataloader_val)
# this is to score after fine-tuning
test = trainer.test(test_dataloaders=dataloader_test)
print(f'Accuracy: {test[0]["accuracy"]:.2f}')
但是我不太确定在微调之前如何进行测试，以便比较微调前后的两个模型，以显示微调的效果。
将以下两行插入### (a) ###：
test = trainer.test(test_dataloaders=dataloader_test)
print(f'Accuracy: {test[0]["accuracy"]:.2f}')
我得到了这个结果：
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
<ipython-input-13-c8b2c67f2d5c> in <module>()
9
10 # 6-19
---> 11 test = trainer.test(test_dataloaders=dataloader_test)
12 print(f'Accuracy: {test[0]["accuracy"]:.2f}')
13
/usr/local/lib/python3.7/dist-packages/pytorch_lightning/trainer/trainer.py in test(self, model, test_dataloaders, ckpt_path, verbose, datamodule)
896 self.verbose_test = verbose
897
--> 898 self._set_running_stage(RunningStage.TESTING, model or self.lightning_module)
899
900 # If you supply a datamodule you can't supply train_dataloader or val_dataloaders
/usr/local/lib/python3.7/dist-packages/pytorch_lightning/trainer/trainer.py in _set_running_stage(self, stage, model_ref)
563 the trainer and the model
564 """
--> 565 model_ref.running_stage = stage
566 self._running_stage = stage
567
AttributeError: 'NoneType' object has no attribute 'running_stage'
我注意到它Trainer.fit()可以None作为除 之外的参数model，所以我尝试了这个：
trainer.fit(model)
test=trainer.test(test_dataloaders=dataloader_test)
print(f'Accuracy: {test[0]["accuracy"]:.2f}')
结果：
MisconfigurationException: No `train_dataloader()` method defined. Lightning `Trainer` expects as minimum a `training_step()`, `train_dataloader()` and `configure_optimizers()` to be defined.
谢谢。
解决方案
Trainer需要调用它.fit()才能设置很多东西然后只有你可以做或.test()其他方法。
你在.fit()前面放一个是对的，.test()但是 fit 调用需要一个有效的调用。您必须为其提供数据加载器/数据模块。但是由于您不想在这个 fit 调用中进行训练/验证，所以limit_[train/val]_batches=0在 Trainer 构建时通过。
trainer = Trainer(gpus=..., ..., limit_train_batches=0, limit_val_batches=0)
trainer.fit(model, dataloader_train, dataloader_val)
trainer.test(model, dataloader_test) # without fine-tuning
这里的 fit 调用只会为您设置好东西并跳过培训/验证。然后进行测试。下次运行相同的代码但没有limit_[train/val]_batches，这将为您进行预训练
trainer = Trainer(gpus=..., ...)
trainer.fit(model, dataloader_train, dataloader_val)
trainer.test(model, dataloader_test) # with fine-tuning
澄清一下除了模型之外的所有内容：它并不完全正确 - 您必须提供.fit()DataLoader或DataModule。None