如何调用checkpoint文件，测试训练效果？

可以使用以下代码调用checkpoint文件，测试训练效果：

from transformers import GPT2LMHeadModel, GPT2Tokenizer

# Load pre-trained model and tokenizer
tokenizer = GPT2Tokenizer.from_pretrained('model_checkpoint_directory')
model = GPT2LMHeadModel.from_pretrained('model_checkpoint_directory')

# Choose a prompt for generation
prompt = "Hello, how are you today?"

# Encode the prompt
input_ids = tokenizer.encode(prompt, return_tensors='pt')

# Generate text using the model
generated_text = model.generate(
    input_ids=input_ids,
    max_length=50,
    top_k=0,
    top_p=0.9,
    temperature=0.8
)

# Decode the generated text
decoded_text = tokenizer.decode(generated_text[0], skip_special_tokens=True)

print(decoded_text)