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import os
import torch
import inspect
from datasets import load_from_disk
from transformers import (
AutoTokenizer,
AutoModelForSequenceClassification,
TrainingArguments,
Trainer
)
from peft import LoraConfig, get_peft_model, TaskType
from sklearn.metrics import accuracy_score, f1_score
# ✅ Hugging Face Token
hf_token = "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"
# ✅ 检查 TrainingArguments 来源
from transformers import TrainingArguments
print("🧠 当前 TrainingArguments 来源:", inspect.getfile(TrainingArguments))
# ✅ 模型与 LoRA 配置
base_model = "Qwen/Qwen2-0.5B-Instruct"
output_dir = "./qwen_lora_checkpoint"
lora_config = LoraConfig(
r=8,
lora_alpha=16,
lora_dropout=0.05,
bias="none",
task_type=TaskType.SEQ_CLS,
target_modules=["q_proj", "v_proj"]
)
# ✅ 加载 tokenizer并设置 pad_token
tokenizer = AutoTokenizer.from_pretrained(
base_model,
token=hf_token,
trust_remote_code=True
)
tokenizer.pad_token = tokenizer.eos_token
pad_token_id = tokenizer.pad_token_id
# ✅ 加载模型(只加载一次),并设置 pad_token_id
base = AutoModelForSequenceClassification.from_pretrained(
base_model,
token=hf_token,
trust_remote_code=True,
num_labels=2
)
base.config.pad_token_id = pad_token_id
# ✅ 应用 LoRA
model = get_peft_model(base, lora_config)
# ✅ 加载数据
dataset = load_from_disk("./qwen_classification_dataset")
def preprocess(example):
return tokenizer(example["text"], truncation=True, padding="max_length", max_length=512)
tokenized_dataset = dataset.map(preprocess, batched=True)
tokenized_dataset = tokenized_dataset.rename_column("label", "labels")
tokenized_dataset.set_format(type="torch", columns=["input_ids", "attention_mask", "labels"])
# ✅ 训练参数(自动使用 GPU / fp16
training_args = TrainingArguments(
output_dir=output_dir,
per_device_train_batch_size=8,
per_device_eval_batch_size=8,
learning_rate=2e-5,
num_train_epochs=3,
evaluation_strategy="epoch",
save_strategy="epoch",
logging_dir=f"{output_dir}/logs",
save_total_limit=2,
load_best_model_at_end=True,
metric_for_best_model="accuracy",
remove_unused_columns=False,
report_to="none",
fp16=torch.cuda.is_available(), # 自动开启 fp16
gradient_accumulation_steps=2,
dataloader_pin_memory=True,
)
# ✅ 评估函数
def compute_metrics(eval_pred):
logits, labels = eval_pred
preds = torch.argmax(torch.tensor(logits), dim=1)
acc = accuracy_score(labels, preds)
f1 = f1_score(labels, preds)
return {"accuracy": acc, "f1": f1}
# ✅ 构建 Trainer
trainer = Trainer(
model=model,
tokenizer=tokenizer,
args=training_args,
train_dataset=tokenized_dataset["train"],
eval_dataset=tokenized_dataset["validation"],
compute_metrics=compute_metrics,
)
# ✅ 开始训练
trainer.train()
# ✅ 保存模型和 tokenizer
model.save_pretrained(output_dir)
tokenizer.save_pretrained(output_dir)
print(f"✅ 微调完成,模型保存在 {output_dir}")