Remove cache in a python HTTP server

Question

I found this server online and I edited it a bit. Here is the code:

from http.server import BaseHTTPRequestHandler, HTTPServer
from xml.dom import minidom
import os


class MyHandler(BaseHTTPRequestHandler):
    def do_POST(self):
        self.data_string = self.rfile.read(int(self.headers['Content-Length']))
        self.send_response(200)
        self.end_headers()
        valore = str(self.data_string)[2:-1]
        response = ["",""]
        response[0],response[1] = processData(valore)
        if response[0] == 1:
            sep = ""
            message = ""
            for res in response[1]:
                message += res
            response = sep.join(message)
            self.wfile.write(bytes(message, "utf-8"))

    def do_GET(self):
        # Send response status code
        self.send_response(200)
        # Send headers
        if self.path.endswith("html"):
            self.send_header('Content-type', 'text/html')
            self.end_headers()
        elif self.path.endswith("css"):
            self.send_header('Content-type', 'text/css')
            self.end_headers()
        elif self.path.endswith("js"):
            self.send_header('Content-type', 'application/javascript')
            self.end_headers()
        elif self.path.endswith(".ico"):
            print(self.rawpath)
        if not self.path.endswith("jpeg") and not self.path.endswith("jpg") and not self.path.endswith("png") and not self.path.endswith("gif"):
            with open(self.path[1:], 'r') as myfile:
                data = myfile.read()
            # Write content as utf-8 data
            self.wfile.write(bytes(data, "utf8"))
        if self.path.endswith("jpeg"):
            f = open(self.path[1:], 'rb')
            self.send_response(200)
            self.send_header('Content-type', 'image/jpeg')
            self.end_headers()
            self.wfile.write(f.read())
            f.close()
        elif self.path.endswith("png"):
            f = open(self.path[1:], 'rb')
            self.send_response(200)
            self.send_header('Content-type', 'image/png')
            self.end_headers()
            self.wfile.write(f.read())
            f.close()
        elif self.path.endswith("gif"):
            f = open(self.path[1:], 'rb')
            self.send_response(200)
            self.send_header('Content-type', 'image/gif')
            self.end_headers()
            self.wfile.write(f.read())
            f.close()
        elif self.path.endswith("jpg"):
            f = open(self.path[1:], 'rb')
            self.send_response(200)
            self.send_header('Content-type', 'image/jpeg')
            self.end_headers()
            self.wfile.write(f.read())
            f.close()
        return

def run():
    print('starting server...')

    # Server settings
    # Choose port 8080, for port 80, which is normally used for a http server, you need root access
    server_address = ('192.168.2.245', 8081)
    httpd = HTTPServer(server_address, MyHandler)
    print('running server...')
    httpd.serve_forever()


def processData(data):
    XMLlist = []
    data = data.split(":")
    if data[0] == "XMLlist":
        path = os.path.realpath(__file__)
        path = os.path.dirname(path)
        for filename in os.listdir(path):
            if filename.endswith('.xml'):
                XMLlist.append(filename[:-3])
        return 1,XMLlist
                #fullname = os.path.join(path, filename)
    else:
        file = open('default.xml', 'r')
        tree = minidom.parse(file)
        tree.getElementsByTagName(data[0])[0].childNodes[0].replaceWholeText(data[1])
        file = open('default.xml', 'w')
        tree.writexml(file)
        file.close()
        return 0, 1


run()

The server works just fine and I need to remove cache. When I try to refresh an Image from the html page with the same name, the server return me the cached image... Do you have any advice?

Thank you and sorry for my english...

Steely Wing · Accepted Answer · 2020-06-20 06:32:19Z

15

http.server does not send "no cache" header, so we need to send "no cache" header

# NoCacheHTTPServer.py

import http.server

PORT = 8000

class NoCacheHTTPRequestHandler(
    http.server.SimpleHTTPRequestHandler
):
    def send_response_only(self, code, message=None):
        super().send_response_only(code, message)
        self.send_header('Cache-Control', 'no-store, must-revalidate')
        self.send_header('Expires', '0')

if __name__ == '__main__':
    http.server.test(
        HandlerClass=NoCacheHTTPRequestHandler,
        port=PORT
    )

Run in CLI

python NoCacheHTTPServer.py

edited Jun 20, 2020 at 6:32

answered Jun 20, 2020 at 5:42

Steely Wing

17.9k10 gold badges63 silver badges55 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

StefansArya · Accepted Answer · 2017-02-20 09:49:10Z

1

Try refresh the browser by pressing Ctrl+F5 or Shift+F5

answered Feb 20, 2017 at 9:49

StefansArya

2,9383 gold badges27 silver badges25 bronze badges

6 Comments

G. Threepwood Over a year ago

Yes, but this doesn't disable the cache from the server...I want that the server doesn't store any cache...is this possible?

StefansArya Over a year ago

self.send_header('Cache-Control', 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0')

StefansArya Over a year ago

it will prevent from caching, I don't think python will cache files.. Have you tried to refresh the server?

G. Threepwood Over a year ago

yes, I refresh the server every change. Maybe I'm wrong and it isn't a server problem. I tell to the image to refresh itself with another image with the same name and the image still the same even if the source image is changed.

G. Threepwood Over a year ago

I solved the problem. It was the browser. I was using Firefox with disabled chaced. I tried with Chrome and everything works! I'm sorry for the taking your time, thank you for the help!

|

Frontendengdev · Accepted Answer · 2024-02-25 18:00:40Z

1

If the purpose of this server is only for the local test (which I think is the most common usecase) you can also disable cache for your Chrome browser.

The detailed instructions to disable cache are here.

answered Feb 25, 2024 at 18:00

Frontendengdev

111 bronze badge

1 Comment

Community Over a year ago

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center.

Collectives™ on Stack Overflow

Remove cache in a python HTTP server

3 Answers 3

Comments

6 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

6 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related