Processing javascript requests on the python server

Question

There is a simple web server server in python.

import socket import json dictionary = {'Hello':'World'} dictionary_json = json.dumps(hardware) def parse_request(request): try: parsed = request.split() method = parsed[0] url = parsed[1] return (method, url) except: pass def generate_headers(method, url): if not method == "GET": return ('HTTP/1.1 405 Method not allowed\n\n', 405) return ('HTTP/1.1 200 OK\n\n', 200) def generate_content(code, url): if code == 404: return '<h1>404</h1><p>Not found</p>' if code == 405: return '<h1>405</h1><p>Method not allowed</p>' return dictionary_json def generate_respose(request): method, url = parse_request(request) headers, code = generate_headers(method, url) body = generate_content(code, url) return (headers + body).encode() def run_server(): server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) server_socket.bind(('localhost', 8080)) server_socket.listen() while True: client_socket, addr = server_socket.accept() request = client_socket.recv(1024) print(request) response = generate_respose(request.decode('utf-8')) print(response) client_socket.sendall(response) client_socket.close()

If you open a browser and go to localhost: 8080, then the contents of dictionary_json will be displayed on the screen. I would like the contents of the dictionary displayed on request javascript. That is, a simple html page with a button that, if pressed, would display the contents of the dictionary.

The question is actually how can this be implemented in the simplest way? I understand you need to use ajax requests and so on, but then how to process them by the server?

qwabra qwabra 2,602 four 20 · Accepted Answer · 2019-02-09T16:29:39

There is a simple web server server in python.
 import socket 

A common mistake is not a "websocket".

if you really want to use WS - read on.

Attention, the recommended library, as well as the code I didn’t check, is the first link from Google ( https://pypi.org/project/websockets/ ).

The following text is a free translation of the part of the "Getting started" article , namely the section "Browser-based example".

Requirements

Python ≥ 3.4 (better than Python ≥ 3.6).

Installation

install dependencies with the following command

 pip install websockets

Browser-based example

This is an example of how to start the WebSocket server and connect to it from a browser.

run this script from the console

 #!/usr/bin/env python # WS server that sends messages at random intervals import asyncio import datetime import random import websockets async def time(websocket, path): while True: now = datetime.datetime.utcnow().isoformat() + 'Z' await websocket.send(now) await asyncio.sleep(random.random() * 3) start_server = websockets.serve(time, '127.0.0.1', 5678) asyncio.get_event_loop().run_until_complete(start_server) asyncio.get_event_loop().run_forever()

then create an index.html file with the following content and open it in a browser (eg from lane: just try dragging the file into the browser)

 <!DOCTYPE html> <html> <head> <title>WebSocket demo</title> </head> <body> <script> var ws = new WebSocket("ws://127.0.0.1:5678/"), messages = document.createElement('ul'); ws.onmessage = function (event) { var messages = document.getElementsByTagName('ul')[0], message = document.createElement('li'), content = document.createTextNode(event.data); message.appendChild(content); messages.appendChild(message); }; document.body.appendChild(messages); </script> </body> </html>

Is it possible to establish an ssl connection between the server and the client?
Just if instead of: var ws = new WebSocket ("ws: //127.0.0.1: 5678 /") Write: var ws = new WebSocket ("wss: //127.0.0.1: 5678 /") In the javascript console, an error occurs: index.html: 55 Web connection connection to 'wss: //127.0.0.1: 5678 /' failed: Error in connection establishment: net :: ERR_SSL_PROTOCOL_ERROR
The only problem I have encountered is that the server is shutting down.
asyncio.get_event_loop (). stop () asyncio.get_event_loop (). close () does not complete anything.
sys.exit () also does not help. I would like to somehow shut down the server and the script completely and correctly.
You are trying to call the close method on the helper library and not on the socket.
Try 'start_server.close ()' for more information, see the documentation, on the left is a konopochka api

Processing javascript requests on the python server

1 answer 1

Requirements

Installation

Browser-based example

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