aiohttp

aiohttp is an asynchronous HTTP client/server framework for Python's `asyncio` library. It allows you to build highly concurrent web applications (servers) and make efficient HTTP requests (clients) without blocking the main thread, making it ideal for I/O-bound tasks like web servers, API clients, and long-polling applications.

Key features include:
- Asynchronous Nature: Fully leverages `async`/`await` for non-blocking operations, enabling high concurrency.
- Client and Server: Provides comprehensive APIs for both creating HTTP servers and making HTTP requests.
- WebSockets: Full support for WebSocket communication, allowing for real-time applications.
- Middlewares: Allows injecting logic into the request/response cycle, useful for authentication, logging, etc.
- Routing: Powerful and flexible URL routing system for defining API endpoints.
- Pluggable: Highly extensible architecture that supports custom components and extensions.
- Streaming: Efficient handling of large data streams for both requests and responses.

aiohttp is particularly popular for building high-performance REST APIs, microservices, and web applications where low latency and high concurrency are critical. By using an event loop, aiohttp can manage many simultaneous connections efficiently, switching between tasks whenever an I/O operation (like network communication or database query) is waiting, instead of blocking the main execution flow. This non-blocking nature significantly improves throughput and responsiveness compared to traditional blocking frameworks for I/O-bound workloads.

import aiohttp.web

async def hello_handler(request):
    """An asynchronous request handler."""
     Get a 'name' from the URL path parameters, default to 'World'
    name = request.match_info.get('name', "World")
    text_response = f"Hello, {name}! This is an aiohttp server."
    return aiohttp.web.Response(text=text_response)

async def create_app():
    """Creates and configures the aiohttp web application."""
    app = aiohttp.web.Application()
     Add routes to the application
    app.router.add_get('/', hello_handler)           e.g., GET / 
    app.router.add_get('/{name}', hello_handler)     e.g., GET /John
    return app

if __name__ == '__main__':
     Run the aiohttp application
     This will start the server on http://localhost:8080 by default
    print("Starting aiohttp server on http://localhost:8080")
    print("Try accessing: http://localhost:8080/ or http://localhost:8080/Alice")
    aiohttp.web.run_app(create_app())