import re


def make_filename(url):
	"""
		Extracts domain from a url and append '.html'

		:param url: string

		return <domain>.html string
	"""
	rx = re.compile(r'^https?:\/\/(?:www.)?([^\/]+)\/?')
	m = rx.search(url)
	if m:
		return m[1]  + '.html'
	else:
		print(f'Can not get domain from {url}')
		exit(0)