HMR
Enables real-time hot module reloading for Python applications, reactively triggering side effects gracefully without full restarts.
About
HMR brings the efficiency of Hot Module Reload (HMR) to Python development, a feature common in frontend frameworks. Unlike traditional Python reloaders that restart the entire application upon any code change, HMR intelligently updates only the necessary parts. This drastically reduces development time by avoiding lengthy initialization processes, such as loading large machine learning models, ensuring changes take effect instantly. It operates by treating the codebase as a dependency graph, rerunning only affected modules, and is robust enough to handle complex Python patterns like lazy imports and circular dependencies, making development smoother and more productive.
Key Features
- Fine-grained Hot Module Reloading for Python
- Supports lazy imports, circular dependencies, and dynamic imports
- 31 GitHub stars
- Production-ready and robust
- Intelligent dependency graph-based updates
- Reactive side effect triggering
Use Cases
- Accelerating development of ML services built with frameworks like FastAPI by avoiding full restarts
- Creating a Vite-like development experience when paired with Uvicorn
- Enabling Vitest-like on-demand testing updates with Pytest
