ThunderWiring/jsfile.js

## jsfile.js
const onLoadClick = () => {
    console.log('Load click')
    var xmlHttp = new XMLHttpRequest();
    xmlHttp.open("GET", '/serve_load', false); // false for synchronous request
    xmlHttp.send(null);
}

## py_server.py
import os
import http.server
from http.server import HTTPServer, SimpleHTTPRequestHandler
from pyscript import save_pic

class ImageRequestHandler(SimpleHTTPRequestHandler):
    def do_GET(self):
        if self.path == '/':
            self.path = '/webviewer.html'
        elif self.path == '/serve_load':
            save_pic()
        return http.server.SimpleHTTPRequestHandler.do_GET(self)

server_object = HTTPServer(server_address=('', 8080), RequestHandlerClass=ImageRequestHandler)
server_object.serve_forever()

## pyscript.py
import requests
import os

class MyBusinessLogic:
    def __init__(self):
        self.urls = [
            'https://i.cbc.ca/1.5256404.1566499707!/fileImage/httpImage/image.jpg_gen/derivatives/16x9_780/cat-behaviour.jpg',
            'https://ichef.bbci.co.uk/news/976/cpsprodpb/12A9B/production/_111434467_gettyimages-1143489763.jpg',
        ]
        self.filename = 'cat_pic.jpg'
        self.idx = 0
        self.pic_url = self.urls[0]

    def do_something(self):
        self.idx += 1
        self.pic_url = self.urls[self.idx % len(self.urls)]
        try:
            os.remove(self.filename)
        except OSError as e:
            print('excep', e)
        with open(self.filename, 'wb') as handle:
            response = requests.get(self.pic_url, stream=True)

            if not response.ok:
                print(response)

            for block in response.iter_content(1024):
                if not block:
                    break

                handle.write(block)

logic = MyBusinessLogic()

def save_pic():
    logic.do_something()

## webviewer.html
<!DOCTYPE html>
<html>
    <script src="jsfile.js"></script>
  <head>
    Demo
  </head>

  <body>
    <div>
    Click to load an Image
    <div>
    <button onclick="onLoadClick()">Load Image</button>
    <div>
        <img id="my_image_id" src="cat_pic.jpg" />
    </div>
  </body>
</html>
	const onLoadClick = () => {
	console.log('Load click')
	var xmlHttp = new XMLHttpRequest();
	xmlHttp.open("GET", '/serve_load', false); // false for synchronous request
	xmlHttp.send(null);
	}
	import os
	import http.server
	from http.server import HTTPServer, SimpleHTTPRequestHandler
	from pyscript import save_pic

	class ImageRequestHandler(SimpleHTTPRequestHandler):
	def do_GET(self):
	if self.path == '/':
	self.path = '/webviewer.html'
	elif self.path == '/serve_load':
	save_pic()
	return http.server.SimpleHTTPRequestHandler.do_GET(self)

	server_object = HTTPServer(server_address=('', 8080), RequestHandlerClass=ImageRequestHandler)
	server_object.serve_forever()
	import requests
	import os

	class MyBusinessLogic:
	def __init__(self):
	self.urls = [
	'https://i.cbc.ca/1.5256404.1566499707!/fileImage/httpImage/image.jpg_gen/derivatives/16x9_780/cat-behaviour.jpg',
	'https://ichef.bbci.co.uk/news/976/cpsprodpb/12A9B/production/_111434467_gettyimages-1143489763.jpg',
	]
	self.filename = 'cat_pic.jpg'
	self.idx = 0
	self.pic_url = self.urls[0]

	def do_something(self):
	self.idx += 1
	self.pic_url = self.urls[self.idx % len(self.urls)]
	try:
	os.remove(self.filename)
	except OSError as e:
	print('excep', e)
	with open(self.filename, 'wb') as handle:
	response = requests.get(self.pic_url, stream=True)

	if not response.ok:
	print(response)

	for block in response.iter_content(1024):
	if not block:
	break

	handle.write(block)

	logic = MyBusinessLogic()

	def save_pic():
	logic.do_something()
	<!DOCTYPE html>
	<html>
	<script src="jsfile.js"></script>
	<head>
	Demo
	</head>

	<body>
	<div>
	Click to load an Image
	<div>
	<button onclick="onLoadClick()">Load Image</button>
	<div>
	<img id="my_image_id" src="cat_pic.jpg" />
	</div>
	</body>
	</html>