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Fast and readable async non-blocking network apps

Netius is a Python network library that can be used for the rapid creation of asynchronous non-blocking servers and clients. It has no dependencies, it's cross-platform, and brings some sample netius-powered servers out of the box, namely a production-ready WSGI server.

Simplicity and performance are the main drivers of this project. The codebase adheres to very strict code standards, and is extensively commented; and as far as performance is concerned, it aims to be up to par with equivalent native implementations, where PyPy can be used to provide the extra boost to raise performance up to these standards.

Bear in mind that although netius is non-blocking, it will naturally still block if the operations performed within the event loop are blocking, like reading or writing a file, which are both blocking operations in the Python standard library. Running multiple netius instances in parallel, and having a fast server like NGINX act as their reverse proxy, is one way of minimising the perceptibility of such blockages.


pip install netius

Or download the source from GitHub.

Netius has no dependencies, and is therefore cross-platform. It's compatible with PyPy, with which it benefits of performance increases up to 1.5x - 2.5x faster in most environments, when compared with running it with the cPython interpreter.


WSGI Server

import netius.servers

def app(environ, start_response):
    status = "200 OK"
    contents = "Hello World"
    content_l = len(contents)
    headers = (
        ("Content-Length", content_l),
        ("Content-Type", "text/plain"),
        ("Connection", "keep-alive")
    start_response(status, headers)
    yield contents

server = netius.servers.WSGIServer(app = app)
server.serve(port = 8080)

HTTP Client

Synchronous usage

import netius.clients
result = netius.clients.HTTPClient.get_s(
    asynchronous = False

Asynchronous usage

import netius.clients

def on_partial(client, parser, data):

def on_message(client, parser, message):

    callback = on_message,
    on_data = on_partial

Test servers

The servers that come with netius out-of-the-box, can be tested through the command line:

WSGIServerpython -m netius.servers.wsgi
FTPServerpython -m netius.servers.ftp
HelloServerMESSAGE="Hello Netius" python -m netius.extra.hello
FileServerBASE_PATH=/ python -m netius.extra.file
SMTPServerpython -m netius.servers.smtp
RelaySMTPServerpython -m netius.extra.smtp_r

Learn more


Advanced topics

More information can be found in the Advanced Topics page.


Netius is currently licensed under the Apache License, Version 2.0.

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