QLoRA Advanced: Continual Learning - Qwen3-4B-Thinking¶

# Environment Setup
import os
from dotenv import load_dotenv
load_dotenv()

# Force text-based progress instead of HTML widgets
os.environ["TQDM_NOTEBOOK"] = "false"

# CRITICAL: Import unsloth FIRST for proper TRL patching
import unsloth
from unsloth import FastLanguageModel, is_bf16_supported

import torch
import gc

# Environment summary
gpu = torch.cuda.get_device_name(0) if torch.cuda.is_available() else "CPU"
print(f"Environment: unsloth {unsloth.__version__}, PyTorch {torch.__version__}, {gpu}")
print(f"HF_TOKEN loaded: {'Yes' if os.environ.get('HF_TOKEN') else 'No'}")

# Helper Functions

def cleanup_memory():
    """Force garbage collection and clear CUDA cache"""
    gc.collect()
    if torch.cuda.is_available():
        torch.cuda.empty_cache()
        torch.cuda.synchronize()

def count_parameters(model):
    """Count trainable vs total parameters"""
    trainable = sum(p.numel() for p in model.parameters() if p.requires_grad)
    total = sum(p.numel() for p in model.parameters())
    return {"trainable": trainable, "total": total, "pct": 100 * trainable / total}

print("Helper functions defined.")

# Domain-Specific Datasets (5 samples each)
from datasets import Dataset

# Stage 1: Medical Terminology
medical_data = [
    {
        "instruction": "Define myocardial infarction.",
        "thinking": "Medical term for heart attack. What's the precise definition? It's about blood flow blockage to the heart muscle. Include the key mechanism.",
        "response": "Myocardial infarction (heart attack) is the death of heart muscle tissue due to prolonged lack of blood supply, typically caused by a blocked coronary artery."
    },
    {
        "instruction": "What is hypertension?",
        "thinking": "Common medical condition. High blood pressure. What are the clinical thresholds? 140/90 is typically the cutoff. Mention risks.",
        "response": "Hypertension is persistently elevated blood pressure (typically >140/90 mmHg). It increases risk of heart disease, stroke, and kidney damage."
    },
    {
        "instruction": "Explain diabetes mellitus.",
        "thinking": "Metabolic disorder. Two types: Type 1 (autoimmune) and Type 2 (resistance). Focus on the core issue: blood sugar regulation.",
        "response": "Diabetes mellitus is a metabolic disorder where the body cannot properly regulate blood glucose due to insufficient insulin production (Type 1) or insulin resistance (Type 2)."
    },
    {
        "instruction": "What is anemia?",
        "thinking": "Blood condition. Reduced red blood cells or hemoglobin. What are the symptoms? Fatigue, weakness. Mention causes.",
        "response": "Anemia is a condition with insufficient red blood cells or hemoglobin to carry adequate oxygen. It causes fatigue, weakness, and pallor. Common causes include iron deficiency and blood loss."
    },
    {
        "instruction": "Define tachycardia.",
        "thinking": "Heart rate term. Fast heart rate. What's the threshold? >100 bpm at rest. Can be normal or pathological.",
        "response": "Tachycardia is a heart rate exceeding 100 beats per minute at rest. It can result from exercise, stress, fever, or underlying cardiac conditions."
    },
]

# Stage 2: Legal Terminology
legal_data = [
    {
        "instruction": "Define tort law.",
        "thinking": "Civil law area. Deals with wrongful acts causing harm. Not criminal. What's the key purpose? Compensation for victims.",
        "response": "Tort law is civil law governing wrongful acts that cause harm to others. It allows injured parties to seek compensation from those responsible, covering negligence, defamation, and intentional wrongs."
    },
    {
        "instruction": "What is due process?",
        "thinking": "Constitutional principle. Fair treatment through legal system. Two types: procedural and substantive. Fundamental right.",
        "response": "Due process is the constitutional guarantee that legal proceedings will be fair and follow established rules. It ensures notice, hearing, and impartial decision-making before depriving rights."
    },
    {
        "instruction": "Explain habeas corpus.",
        "thinking": "Latin: 'produce the body.' Protection against unlawful detention. Court order to bring detained person before judge.",
        "response": "Habeas corpus is a legal action requiring authorities to bring a detained person before a court to determine if their imprisonment is lawful. It protects against arbitrary detention."
    },
    {
        "instruction": "What is legal precedent?",
        "thinking": "Stare decisis principle. Past decisions guide future cases. Creates consistency in law. Binding vs persuasive precedent.",
        "response": "Legal precedent (stare decisis) is the principle that courts should follow previous decisions in similar cases. It creates predictability and consistency in legal interpretation."
    },
    {
        "instruction": "Define liability.",
        "thinking": "Legal responsibility. Can be civil or criminal. Obligation arising from wrongful act. Leads to damages or penalties.",
        "response": "Liability is legal responsibility for one's actions or omissions. In civil law, it typically means obligation to pay damages. In criminal law, it can mean facing penalties."
    },
]

# Stage 3: Technical Terminology
technical_data = [
    {
        "instruction": "Explain API endpoints.",
        "thinking": "Web development concept. URLs that accept requests. Part of REST APIs. Each endpoint serves a specific function.",
        "response": "API endpoints are specific URLs where an API receives requests. Each endpoint corresponds to a resource or action, like '/users' for user data or '/posts' for content."
    },
    {
        "instruction": "What is REST?",
        "thinking": "Architectural style for web services. Stateless, uses HTTP methods. Resources identified by URIs. Widely adopted.",
        "response": "REST (Representational State Transfer) is an architectural style for web APIs using HTTP methods (GET, POST, PUT, DELETE) to perform stateless operations on resources identified by URIs."
    },
    {
        "instruction": "Define microservices.",
        "thinking": "Software architecture. Small, independent services. Each handles specific function. Contrast with monolith.",
        "response": "Microservices is an architecture where applications are built as collections of small, independent services. Each service handles a specific function and communicates via APIs."
    },
    {
        "instruction": "What is containerization?",
        "thinking": "Deployment technology. Packages app with dependencies. Docker is common example. Lighter than VMs.",
        "response": "Containerization packages applications with their dependencies into isolated containers. Unlike VMs, containers share the host OS kernel, making them lightweight and portable."
    },
    {
        "instruction": "Explain CI/CD.",
        "thinking": "DevOps practice. Continuous Integration, Continuous Deployment. Automate testing and deployment. Speed up releases.",
        "response": "CI/CD (Continuous Integration/Continuous Deployment) automates code integration, testing, and deployment. CI merges code changes frequently; CD automatically deploys tested code to production."
    },
]

TRAINING_STAGES = [
    ("medical", medical_data),
    ("legal", legal_data),
    ("technical", technical_data),
]

# Test prompts for retention testing
RETENTION_TESTS = {
    "medical": "What is hypertension?",
    "legal": "What is due process?",
    "technical": "What is REST?",
}

print(f"Training stages prepared:")
for name, data in TRAINING_STAGES:
    print(f"  - {name}: {len(data)} samples")

# Final cleanup
del model, tokenizer
cleanup_memory()
print("Model unloaded and memory cleared.")

# Shutdown kernel to release all GPU memory
import IPython
print("Shutting down kernel to release GPU memory...")
app = IPython.Application.instance()
app.kernel.do_shutdown(restart=False)