18.5. asyncio — Asynchronous I/O, event loop, coroutines and tasks

Source code:

This module provides infrastructure for writing single-threaded concurrent code using coroutines, multiplexing I/O access over sockets and other resources, running network clients and servers, and other related primitives. Here is a more detailed list of the package contents:

• a pluggable event loop with various system-specific implementations;

• and protocol abstractions (similar to those in );

• a Future class that mimics the one in the module, but adapted for use with the event loop;

• coroutines and tasks based on (PEP 380), to help write concurrent code in a sequential fashion;

• cancellation support for s and coroutines;

• synchronization primitives for use between coroutines in a single thread, mimicking those in the module;

Asynchronous programming is more complex than classical “sequential” programming: see the Develop with asyncio page which lists common traps and explains how to avoid them. during development to detect common issues.

Table of contents:

• 18.5.1. Base Event Loop
  • 18.5.1.2. Calls
  • 18.5.1.4. Futures
  • 18.5.1.6. Creating connections
  • 18.5.1.8. Watch file descriptors
  • 18.5.1.10. Resolve host name
  • 18.5.1.12. UNIX signals
  • 18.5.1.14. 错误处理API
  • 18.5.1.16. Server
  • 18.5.1.18. Event loop examples
    • 18.5.1.18.2. 使用 call_later() 来展示当前的日期
    • 18.5.1.18.4. 为SIGINT和SIGTERM设置信号处理器
• • 18.5.2.1. 事件循环函数
  • 18.5.2.3. 平台支持
    • 18.5.2.3.2. Mac OS X
  • 18.5.2.5. 事件循环策略接口
• 18.5.3. Tasks and coroutines
  • • 18.5.3.1.1. Example: Hello World coroutine
    • 18.5.3.1.3. Example: Chain coroutines
  • 18.5.3.3. TimeoutError
  • • 18.5.3.4.1. Example: Future with run_until_complete()
  • 18.5.3.5. Task
  • 18.5.3.6. Task functions
• • 18.5.4.1. 传输
    • 18.5.4.1.2. ReadTransport
    • 18.5.4.1.4. DatagramTransport
  • 18.5.4.2. 协议
    • 18.5.4.2.2. Connection callbacks
    • 18.5.4.2.4. Datagram protocols
    • 18.5.4.2.6. Coroutines and protocols
  • • 18.5.4.3.1. TCP echo client protocol
    • 18.5.4.3.3. UDP echo client protocol
    • 18.5.4.3.5. Register an open socket to wait for data using a protocol
• • 18.5.5.1. Stream functions
  • 18.5.5.3. StreamWriter
  • 18.5.5.6. LimitOverrunError
  • • 18.5.5.7.1. 使用流的 TCP 回显客户端
    • 18.5.5.7.3. 获取 HTTP 标头
• 18.5.6. Subprocess
  • 18.5.6.2. Create a subprocess: high-level API using Process
  • 18.5.6.4. 常量
  • 18.5.6.6. Subprocess and threads
  • • 18.5.6.7.1. Subprocess using transport and protocol
• 18.5.7. Synchronization primitives
  • • 18.5.7.1.1. Lock
    • 18.5.7.1.3. Condition
  • • 18.5.7.2.1. Semaphore
• 18.5.8. 队列集
  • 18.5.8.2. PriorityQueue
  • • 18.5.8.3.1. 异常
• • 18.5.9.1. Debug mode of asyncio
  • 18.5.9.3. Concurrency and multithreading
  • 18.5.9.5. 日志记录
  • 18.5.9.7. Detect exceptions never consumed
  • 18.5.9.9. Pending task destroyed

参见

The module was designed in PEP 3156. For a motivational primer on transports and protocols, see .