To disable the browser cache on Python's simple HTTP server

Simple HTTP server http.server

A simple HTTP server for accessing local HTML files from a browser can be started with the following command if you have Python.

$ python -m http.server 8080
Serving HTTP on 0.0.0.0 port 8080 (http://0.0.0.0:8080/) ...

If you execute this command and access http: // localhost: 8080 / with a browser on the same PC, index.html in the current directory will be displayed.

trouble

Even if the cache is effective in the browser and reloading, the browser may not make a request to the simple HTTP server, and even if you edit the local file, you may not be able to check it with the browser. You can clear the cache from your browser, but it's a hassle.

Therefore, the cache expiration date of 0 is included in the response from the simple HTTP server.

Cache-disabled Python script

import http.server
import sys

port = int(sys.argv[1])

class NoCacheHTTPRequestHandler(http.server.SimpleHTTPRequestHandler):
    def end_headers(self):
        self.send_header('Cache-Control', 'max-age=0')
        self.send_header('Expires', '0')
        super().end_headers()

httpServer = http.server.HTTPServer(('', port), NoCacheHTTPRequestHandler)
httpServer.serve_forever()

If you save this script with a name such as server.py, the following command will start the server.

$ python server.py 8080

You can also check the response header with the curl command. Open another terminal and run it.

$ curl -I http://localhost:8080/
HTTP/1.0 200 OK
Server: SimpleHTTP/0.6 Python/3.8.3
Date: Thu, 12 Nov 2020 13:31:44 GMT
Content-type: text/html
Content-Length: 1178
Last-Modified: Thu, 12 Nov 2020 13:21:38 GMT
Cache-Control: max-age=0
Expires: 0

Your browser will now send you a request every time, and any changes to your local file will take effect immediately.

version information

$ python --version
Python 3.8.3