D.6 Verifying Your Setup

After completing the installation steps, run this verification script to confirm everything is working. Save it as verify_setup.py and run it in your activated environment.

"""
LLM Environment Verification Script
Run this to confirm your setup is ready for the textbook exercises.
"""
import sys

def check_python():
    v = sys.version_info
    assert v.major == 3 and v.minor >= 10, f"Need Python 3.10+, got {v.major}.{v.minor}"
    print(f"[OK] Python {v.major}.{v.minor}.{v.micro}")

def check_torch():
    import torch
    print(f"[OK] PyTorch {torch.__version__}")
    if torch.cuda.is_available():
        print(f"[OK] CUDA {torch.version.cuda}, GPU: {torch.cuda.get_device_name(0)}")
        vram = torch.cuda.get_device_properties(0).total_mem / 1e9
        print(f"     VRAM: {vram:.1f} GB")
    else:
        print("[WARN] No CUDA GPU detected. CPU-only mode.")

def check_transformers():
    import transformers
    print(f"[OK] Transformers {transformers.__version__}")

def check_optional(name):
    try:
        mod = __import__(name)
        version = getattr(mod, "__version__", "installed")
        print(f"[OK] {name} {version}")
    except ImportError:
        print(f"[SKIP] {name} not installed (optional)")

def test_inference():
    """Quick smoke test: load a tiny model and generate one token."""
    from transformers import pipeline
    gen = pipeline("text-generation", model="sshleifer/tiny-gpt2", device="cpu")
    output = gen("Hello", max_new_tokens=5)
    assert len(output[0]["generated_text"]) > 0
    print("[OK] Inference smoke test passed")

if __name__ == "__main__":
    print("=== LLM Environment Check ===")
    check_python()
    check_torch()
    check_transformers()

    for lib in ["datasets", "peft", "trl", "bitsandbytes", "wandb", "vllm"]:
        check_optional(lib)

    print("\n=== Smoke Test ===")
    test_inference()

    print("\n=== All checks complete! ===")

Expected output on a properly configured machine with an NVIDIA GPU:

# Experiment tracking setup
# Key operations: experiment tracking, dependency installation
=== LLM Environment Check ===
[OK] Python 3.11.7
[OK] PyTorch 2.5.1
[OK] CUDA 12.4, GPU: NVIDIA GeForce RTX 4090
     VRAM: 24.0 GB
[OK] Transformers 4.47.0
[OK] datasets 3.2.0
[OK] peft 0.14.0
[OK] trl 0.13.0
[OK] bitsandbytes 0.45.0
[OK] wandb 0.19.1
[SKIP] vllm not installed (optional)

=== Smoke Test ===
[OK] Inference smoke test passed

=== All checks complete!