asyncio — Asynchronous I/O¶
Hello World!
importasyncioasyncdefmain():print('Hello ...')awaitasyncio.sleep(1)print('... World!')# Python 3.7+asyncio.run(main())
asyncio is a library to writeconcurrent code usingtheasync/await syntax.
asyncio is used as a foundation for multiple Python asynchronousframeworks that provide high-performance network and web-servers,database connection libraries, distributed task queues, etc.
asyncio is often a perfect fit for IO-bound and high-levelstructured network code.
asyncio provides a set ofhigh-level APIs to:
run Python coroutines concurrently andhave full control over their execution;
performnetwork IO and IPC;
controlsubprocesses;
distribute tasks viaqueues;
synchronize concurrent code;
Additionally, there arelow-level APIs forlibrary and framework developers to:
create and manageevent loops, whichprovide asynchronous APIs for
networking,runningsubprocesses,handlingOSsignals, etc;implement efficient protocols usingtransports;
bridge callback-based libraries and codewith async/await syntax.
Reference
Guides and Tutorials
Note
The source code for asyncio can be found inLib/asyncio/.