import torch
from transformers import AutoModelForCausalLM, AutoTokenizer, BitsAndBytesConfig
from peft import PeftModel
base_model_id = "Qwen/Qwen3-1.7B"
adapter_id = "ehzawad/qwen3-1.7b-gsm8k-grpo"
bnb_config = BitsAndBytesConfig(
load_in_4bit=True,
bnb_4bit_quant_type="nf4",
bnb_4bit_compute_dtype=torch.bfloat16,
)
base_model = AutoModelForCausalLM.from_pretrained(
base_model_id,
quantization_config=bnb_config,
device_map="auto",
)
tokenizer = AutoTokenizer.from_pretrained(adapter_id)
hf_model = PeftModel.from_pretrained(base_model, adapter_id, is_trainable=False)
hf_model.eval()
prompt = "Janet has 3 bags with 4 apples each. She gives away 5 apples. How many remain?"
system_prompt = (
"You are a careful math reasoning assistant. "
"Solve the problem step by step, but keep the solution concise. "
"End with exactly one final answer in the form \boxed{answer}."
)
messages = [
{"role": "system", "content": system_prompt},
{"role": "user", "content": prompt}
]
inputs = tokenizer.apply_chat_template(
messages,
tokenize=True,
add_generation_prompt=True,
return_tensors="pt",
return_dict=True
).to(hf_model.device)
with torch.inference_mode():
outputs = hf_model.generate(
**inputs,
max_new_tokens=512,
temperature=0.6,
do_sample=True,
)
response = tokenizer.decode(outputs[0][inputs["input_ids"].shape[-1]:], skip_special_tokens=True)
print(response)