qmd/finetune/rl.py
Tobi Lutke 32706a720f
Refactor finetune folder: train/rl scripts with YAML configs
Major changes:
- train.py: Generic SFT training script using YAML config
- rl.py: Generic GRPO training script using YAML config
- configs/: YAML configs per training run (sft_v4.yaml, grpo_v4.yaml)
- dataset/: Data preparation scripts moved here
- tui.py: Interactive model testing interface

Training results:
- SFT v4: 98.8% avg score (all Excellent)
- GRPO v4: 0% (failed - model drifted to verbose explanations)

Removed per-model scripts (train_0.6B.py, train_1.7B.py, etc)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-24 20:26:46 -05:00

334 lines
10 KiB
Python

# /// script
# requires-python = ">=3.10"
# dependencies = [
# "trl>=0.12.0",
# "peft>=0.7.0",
# "transformers>=4.45.0",
# "accelerate>=0.24.0",
# "huggingface_hub>=0.20.0",
# "trackio",
# "datasets",
# "bitsandbytes",
# "pyyaml",
# ]
# ///
"""
GRPO (Group Relative Policy Optimization) training for QMD query expansion.
Uses the scoring system from SCORING.md as the reward function.
Usage:
uv run rl.py --config configs/grpo_v4.yaml
uv run rl.py --config configs/grpo_v4.yaml --dry-run
"""
import os
import re
import argparse
import yaml
import torch
import trackio
from collections import Counter
from datasets import load_dataset
from huggingface_hub import login
from peft import LoraConfig, PeftModel, get_peft_model
from transformers import AutoModelForCausalLM, AutoTokenizer
from trl import GRPOTrainer, GRPOConfig
STOPWORDS = {'the', 'a', 'an', 'is', 'are', 'to', 'for', 'of', 'in', 'and', 'or', 'it', 'this', 'that', 'be', 'with', 'as', 'on', 'by'}
KEY_TERM_STOPWORDS = {'what', 'is', 'how', 'to', 'the', 'a', 'an', 'in', 'on', 'for', 'of',
'and', 'or', 'with', 'my', 'your', 'do', 'does', 'can', 'i', 'me', 'we'}
def get_key_terms(query: str) -> set:
words = set(query.lower().split())
return words - KEY_TERM_STOPWORDS
def lex_preserves_key_terms(lex_line: str, query: str) -> bool:
key_terms = get_key_terms(query)
if not key_terms:
return True
lex_words = set(lex_line.lower().split())
return bool(key_terms & lex_words)
def parse_expansion(text: str) -> dict:
lines = text.strip().split("\n")
result = {"lex": [], "vec": [], "hyde": [], "invalid": []}
for line in lines:
line = line.strip()
if not line:
continue
if line.startswith("lex:"):
result["lex"].append(line[4:].strip())
elif line.startswith("vec:"):
result["vec"].append(line[4:].strip())
elif line.startswith("hyde:"):
result["hyde"].append(line[5:].strip())
else:
result["invalid"].append(line)
return result
def edit_distance_simple(a: str, b: str) -> int:
words_a = set(a.lower().split())
words_b = set(b.lower().split())
return len(words_a ^ words_b)
def is_diverse(a: str, b: str, min_distance: int = 2) -> bool:
a, b = a.lower().strip(), b.lower().strip()
if a == b:
return False
if a in b or b in a:
return False
return edit_distance_simple(a, b) >= min_distance
def echoes_query(expansion: str, query: str) -> bool:
exp = expansion.lower().strip()
q = query.lower().strip()
if exp == q:
return True
if q in exp and len(exp) < len(q) + 10:
return True
return False
def word_repetition_penalty(text: str) -> int:
words = re.findall(r'\b\w+\b', text.lower())
counts = Counter(words)
penalty = 0
for word, count in counts.items():
if count >= 3 and word not in STOPWORDS and len(word) > 2:
penalty += (count - 2) * 2
return penalty
def score_expansion(query: str, expansion: str) -> float:
"""Score expansion. Returns 0.0-1.0 for RL reward."""
text = expansion.strip()
# HARD FAIL: Must start with valid prefix (prevents verbose explanations)
first_line = text.split("\n")[0].strip() if text else ""
if not first_line.startswith(("lex:", "vec:", "hyde:")):
return 0.0 # Zero reward for wrong format
parsed = parse_expansion(expansion)
# FORMAT (0-30)
format_score = 0
if parsed["lex"]:
format_score += 10
if parsed["vec"]:
format_score += 10
if not parsed["invalid"]:
format_score += 10
else:
format_score += max(0, 10 - len(parsed["invalid"]) * 5)
# DIVERSITY (0-30)
diversity_score = 0
types_present = sum(1 for t in ["lex", "vec"] if parsed[t])
if types_present >= 2:
diversity_score += 10
total_expansions = len(parsed["lex"]) + len(parsed["vec"])
if total_expansions >= 2:
diversity_score += 5
lex_score = 5
for i, a in enumerate(parsed["lex"]):
for b in parsed["lex"][i+1:]:
if not is_diverse(a, b, 2):
lex_score -= 2
diversity_score += max(0, lex_score)
vec_score = 5
for i, a in enumerate(parsed["vec"]):
for b in parsed["vec"][i+1:]:
if not is_diverse(a, b, 3):
vec_score -= 2
diversity_score += max(0, vec_score)
echo_score = 5
for exp in parsed["lex"] + parsed["vec"]:
if echoes_query(exp, query):
echo_score -= 3
diversity_score += max(0, echo_score)
# HYDE (0-20)
hyde_score = 0
if parsed["hyde"]:
hyde_text = parsed["hyde"][0]
hyde_score += 5
hyde_len = len(hyde_text)
if 50 <= hyde_len <= 200:
hyde_score += 5
elif hyde_len < 50:
hyde_score += 2
if "\n" not in hyde_text:
hyde_score += 5
rep_penalty = word_repetition_penalty(hyde_text)
hyde_score += max(0, 5 - rep_penalty)
# QUALITY (0-20)
quality_score = 5
if parsed["lex"] and parsed["vec"]:
avg_lex = sum(len(l) for l in parsed["lex"]) / len(parsed["lex"])
avg_vec = sum(len(v) for v in parsed["vec"]) / len(parsed["vec"])
if avg_lex <= avg_vec:
quality_score += 5
if parsed["vec"]:
natural = sum(1 for v in parsed["vec"] if " " in v and len(v) > 15)
if natural == len(parsed["vec"]):
quality_score += 5
else:
quality_score += 2
if parsed["lex"]:
lex_with_terms = sum(1 for l in parsed["lex"] if lex_preserves_key_terms(l, query))
if lex_with_terms == len(parsed["lex"]):
quality_score += 5
elif lex_with_terms > 0:
quality_score += 2
total = format_score + diversity_score + hyde_score + quality_score
max_possible = 100 if parsed["hyde"] else 80
return total / max_possible
def extract_query_from_prompt(prompt: str) -> str:
if "Expand this search query:" in prompt:
return prompt.split("Expand this search query:")[-1].strip()
return prompt.strip()
class QMDRewardFunction:
__name__ = "qmd_scoring_reward"
def __call__(self, completions: list[str], prompts: list[str] = None, **kwargs) -> list[float]:
rewards = []
for i, completion in enumerate(completions):
query = ""
if prompts and i < len(prompts):
query = extract_query_from_prompt(prompts[i])
score = score_expansion(query, completion)
rewards.append(score)
return rewards
def main():
parser = argparse.ArgumentParser()
parser.add_argument("--config", type=str, required=True, help="Path to config YAML")
parser.add_argument("--dry-run", action="store_true")
args = parser.parse_args()
with open(args.config) as f:
cfg = yaml.safe_load(f)
if args.dry_run:
print("GRPO Training Configuration:")
print(yaml.dump(cfg, default_flow_style=False))
print("\nTesting reward function...")
test_good = "lex: auth setup\nlex: authentication config\nvec: how to configure authentication\nhyde: Configure auth by setting AUTH_SECRET."
test_bad = "auth is important for security"
print(f" Good output score: {score_expansion('auth', test_good):.2f}")
print(f" Bad output score: {score_expansion('auth', test_bad):.2f}")
return
# Login
hf_token = os.environ.get("HF_TOKEN")
if hf_token:
print("Logging in to HuggingFace Hub...")
login(token=hf_token)
# Load dataset
print("Loading dataset...")
dataset = load_dataset(cfg["dataset"]["name"], split="train")
def extract_prompt(example):
return {"prompt": example[cfg["dataset"]["prompt_field"]][0]["content"]}
dataset = dataset.map(extract_prompt, remove_columns=dataset.column_names)
max_samples = cfg["dataset"].get("max_samples", len(dataset))
dataset = dataset.shuffle(seed=42).select(range(min(max_samples, len(dataset))))
print(f"Using {len(dataset)} prompts for GRPO")
# Load tokenizer and model
print(f"Loading tokenizer from {cfg['model']['base']}...")
tokenizer = AutoTokenizer.from_pretrained(cfg["model"]["base"])
if tokenizer.pad_token is None:
tokenizer.pad_token = tokenizer.eos_token
print(f"Loading SFT model from {cfg['model']['sft']}...")
base_model = AutoModelForCausalLM.from_pretrained(
cfg["model"]["base"],
torch_dtype=torch.bfloat16,
device_map="auto",
)
model = PeftModel.from_pretrained(base_model, cfg["model"]["sft"])
model = model.merge_and_unload()
print("Model loaded and LoRA merged.")
# Add LoRA for GRPO
grpo_lora_config = LoraConfig(
r=cfg["lora"]["rank"],
lora_alpha=cfg["lora"]["alpha"],
lora_dropout=cfg["lora"]["dropout"],
bias="none",
task_type="CAUSAL_LM",
target_modules=cfg["lora"]["target_modules"],
)
model = get_peft_model(model, grpo_lora_config)
model.print_trainable_parameters()
# Reward function
reward_fn = QMDRewardFunction()
# GRPO config
config = GRPOConfig(
output_dir=cfg["model"]["output"].split("/")[-1],
push_to_hub=True,
hub_model_id=cfg["model"]["output"],
num_generations=cfg["grpo"]["num_generations"],
max_completion_length=cfg["grpo"]["max_completion_length"],
num_train_epochs=cfg["training"]["epochs"],
per_device_train_batch_size=cfg["training"]["batch_size"],
gradient_accumulation_steps=cfg["training"]["gradient_accumulation_steps"],
learning_rate=cfg["training"]["learning_rate"],
max_grad_norm=cfg["training"]["max_grad_norm"],
logging_steps=10,
save_strategy="epoch",
report_to="trackio",
project=cfg["tracking"]["project"],
run_name=cfg["tracking"]["run_name"],
)
# Train
print("Initializing GRPO trainer...")
trainer = GRPOTrainer(
model=model,
processing_class=tokenizer,
args=config,
train_dataset=dataset,
reward_funcs=[reward_fn],
)
print("Starting GRPO training...")
trainer.train()
print("Pushing to Hub...")
trainer.push_to_hub()
trackio.finish()
print(f"Done! Model at: https://huggingface.co/{cfg['model']['output']}")
if __name__ == "__main__":
main()