Python developer tools
Every listing tagged python, A to Z: 5 tools across 1 category. Listed in alphabetical order, not ranked.
Axolotl
Free, open-source (Apache-2.0) fine-tuning framework: one YAML config covers dataset prep, training, evaluation and quantization. Full fine-tuning, LoRA, QLoRA, DPO, KTO, ORPO and GRPO on NVIDIA or AMD GPUs, multi-GPU with FSDP2 or DeepSpeed and multi-node with Torchrun or Ray.
capo-s3
Typed, async-first Python SDK for Amazon S3 and S3-compatible storage (RustFS, MinIO, Cloudflare R2), with asyncio and trio support, a matching sync client, multipart transfers and presigned URLs. Part of capo, an MIT-licensed community alternative to boto3 built on its own HTTP stack.
Guardrails AI
Open-source (Apache-2.0) Python framework for LLM guardrails: wrap model calls in Guards that run validators on input and output, from PII and toxicity checks to your own rules, and get structured data back. Validators come from Guardrails Hub as pip packages, and it runs in your code or as a REST server with guardrails start.
NVIDIA NeMo Guardrails
NVIDIA's open-source (Apache-2.0) toolkit for programmable guardrails on LLM apps: input, output, dialog and retrieval rails that keep a bot on topic, detect jailbreaks and prompt injection, fact-check and moderate output. Configured in YAML and Colang, Python 3.10 to 3.13, works with LangChain.
Unsloth
Open-source fine-tuning library and desktop app for your own GPU or a free Colab notebook: LoRA, QLoRA, full fine-tuning, GRPO, DPO and FP8 for LLMs, vision, TTS and embedding models, which Unsloth says train 2x faster with 70% less VRAM. Exports to GGUF. Core Apache-2.0, Studio UI AGPL-3.0; Windows, Linux and macOS.