How to use Llama for code generation
Quick answer
Use the
llama_cpp Python package to load a Llama GGUF model locally and generate code by calling create_chat_completion with a code prompt. This approach enables efficient, offline code generation with Llama models like llama-3.1-8b-instruct.PREREQUISITES
Python 3.8+pip install llama-cpp-pythonDownload a Llama GGUF model file (e.g., llama-3.1-8b-instruct.gguf)Basic Python knowledge
Setup
Install the llama-cpp-python package and download a Llama GGUF model from Hugging Face or a trusted source. Ensure you have Python 3.8 or higher.
pip install llama-cpp-python Step by step
Load the Llama model locally and generate code by sending a prompt in chat format. The example below uses llama-3.1-8b-instruct.gguf and generates Python code for a factorial function.
from llama_cpp import Llama
# Initialize the Llama model with the local GGUF file
llm = Llama(model_path="./llama-3.1-8b-instruct.gguf", n_ctx=2048)
# Create a chat completion with a code generation prompt
response = llm.create_chat_completion(messages=[
{"role": "user", "content": "Write a Python function to compute factorial recursively."}
], max_tokens=256)
print(response["choices"][0]["message"]["content"]) output
def factorial(n):
if n == 0:
return 1
else:
return n * factorial(n - 1) Common variations
- Async usage: The
llama-cpp-pythonpackage currently does not support async calls natively; wrap calls in async functions if needed. - Streaming output: Streaming is not supported in the Python API; generate full completions instead.
- Different models: Use other GGUF Llama models like
llama-3.3-70b.gguffor larger capacity, adjustingmodel_pathaccordingly.
Troubleshooting
- If you see
FileNotFoundError, verify themodel_pathpoints to the correct GGUF model file. - If memory errors occur, reduce
n_ctxor use a smaller model. - For slow inference, ensure you have GPU support configured or use a smaller model.
Key Takeaways
- Use
llama-cpp-pythonwith GGUF models for local, efficient code generation. - Call
create_chat_completionwith a code prompt to generate code snippets. - Adjust model size and context length based on hardware capabilities.
- Streaming and async are not currently supported in the official Python API.
- Ensure correct model file path and sufficient memory to avoid errors.