Copying URL parameters from referrer

referrer.py

@app.before_request
def prepare_private_key():
	
	# Done if private_key in args
	key_from_args = request.args.get('private_key')
	if key_from_args:
		return

	# Check referrer for private key
	parsed_referrer = urllib.urlparse(request.referrer)
	referrer_args = dict(urllib.parse_qsl(parsed_referrer.query))
	key_from_referrer = referrer_args.get('private_key')

	# Update URL and redirect
	if key_from_referrer:
		parsed_path = urllib.urlparse(request.path)
		path_args = dict(urllib.parse_qsl(parsed_path.query))
		path_args['private_key'] = key_from_referrer
		new_parsed_path = parsed_path._replace(query=urllib.urlencode(path_args))
		new_path = urlparse.urlunparse(new_parsed_path)
		return redirect(new_path, code=307)