pyserial-asyncio-fast

0.16 verified Fri May 01 auth: no python

Asyncio-based serial port I/O for Python, built on pyserial. Provides async wrappers for serial communication with support for timeouts and cancellation. Current version 0.16 (2024-04-09).

pip install pyserial-asyncio-fast

Common errors

error ModuleNotFoundError: No module named 'serial_asyncio' ↓

cause Installed the wrong package or used the old import path.

fix

Install pyserial-asyncio-fast and use 'import serial_asyncio_fast' (underscores).

error AttributeError: module 'serial_asyncio_fast' has no attribute 'create_serial_connection' ↓

cause Function may be named 'open_serial_connection' in this version.

fix

Use 'serial_asyncio_fast.open_serial_connection' instead.

error NotImplementedError: Event loop is not running ↓

cause Called async function outside of an asyncio event loop.

fix

Wrap the call in asyncio.run() or run within a running loop.

Warnings

deprecated pyserial-asyncio (original) is deprecated. Use pyserial-asyncio-fast (faster, maintained). ↓

fix pip install pyserial-asyncio-fast and change imports from 'serial_asyncio' to 'serial_asyncio_fast'.

gotcha open_serial_connection returns (asyncio.StreamReader, asyncio.StreamWriter), not a custom transport. Writers must be explicitly closed. ↓

fix Always call writer.close() after use, ideally in a try/finally block.

gotcha The package uses 'serial_asyncio_fast' (with underscore), not 'serial-asyncio-fast' (hyphen). Common import error. ↓

fix Use 'import serial_asyncio_fast' (underscores).

Imports

SerialTransport

wrong

from serial_asyncio import SerialTransport

correct

import serial_asyncio_fast as s; s.SerialTransport

Wrong package: pyserial-asyncio (old) vs pyserial-asyncio-fast

create_serial_connection

wrong

from serial_asyncio import create_serial_connection

correct

from serial_asyncio_fast import create_serial_connection

Wrong package: pyserial-asyncio (old) vs pyserial-asyncio-fast

Quickstart

Open a serial connection and read/write asynchronously.

import asyncio
import serial_asyncio_fast

async def main():
    reader, writer = await serial_asyncio_fast.open_serial_connection(url='/dev/ttyUSB0', baudrate=115200)
    writer.write(b'hello')
    data = await reader.read(100)
    print(data)
    writer.close()

asyncio.run(main())