ansio

Ansio is a lightweight open-source asynchronous input/output library for Python, designed to simplify concurrent programming and I/O-bound workflows. It provides high-level abstractions for asynchronous operations while building on top of Python's asyncio event loop. The project aims to offer a clean, minimal API that reduces boilerplate and improves code readability for asynchronous programs.

Design and architecture: Ansio exposes a small set of primitives that map to common asynchronous tasks, such as scheduling coroutines, performing non-blocking I/O, and handling cancellations and timeouts. It emphasizes structured concurrency, allowing developers to group related tasks and propagate exceptions in a predictable way. While it relies on asyncio under the hood, ansio exposes a stable interface that can be used across compatible Python versions.

Key features include task groups for coordinated cancellation, built-in timeouts and retry semantics, high-level I/O streams and sockets, and integration with existing asyncio code. The library focuses on portability and minimal dependencies, aiming to be easy to adopt for projects already using Python’s async/await syntax.

Usage: Developers import ansio modules to create tasks, await coroutines, and use context managers to manage resources. Typical patterns include launching a group of tasks and awaiting their completion, and using timeouts to guard I/O operations. The API is designed to feel familiar to users of asyncio while providing a concise subset of features.

Relation to the ecosystem: Ansio is intended as a complementary tool to asyncio, not a replacement. It can interoperate with existing asyncio code and third-party libraries that use the Python async ecosystem.

See also: asyncio, Python (programming language), asynchronous programming.