SNISS

import re
import requests

requisicao = requests.get(input('enter the entire website link: '))
padrao = re.findall(r'[\w\.]+@[\w-]+\.[\w\.-]+', requisicao.text)

if padrao:
    print (padrao)
else:
    print ('emails not found ')

SNISS

import urllib
import urllib.request
from time import sleep

try:

    print ('Se vc estiver sem conexão o site não estará acessivel')
    sleep(1)
    site = urllib.request.urlopen(input('Digite o link do site com http Ex(https://www.youtube.com/): '))