Simple code that checks for changes in a website's HTML

website_diff.py

# coding: utf-8
# (C) Júlio Barreto
# 22/09/2018
'''
Script to monitor any website's HTML changes
'''

import urllib2, smtplib
from getpass import getpass
from time import sleep
from email.MIMEMultipart import MIMEMultipart
from email.MIMEText import MIMEText
from datetime import datetime

previous = None # previous HTML
current = None # current HTML
url = '' # INSERT THE WEBSITE HERE
my_email = raw_input('Insert your email: ') # INSERT YOUR EMAIL HERE
pw = getpass("Insert your email's password: ") # User inputs his email's password

server = smtplib.SMTP('smtp.gmail.com', 587) # Connects to Gmail
# IMPORTANT: gmail often blocks the connection. If you are sure that
# you are typing your password correctly, go to your google account
# settings and allow less secure apps. To connect with hotmail, use
# smtp.live.com instead of smtp.gmail.com
server.starttls()

server.login(my_email, pw)

def download_html(errors=0):
	'''
	Downloads the page's HTML. If it is impossible to download,
	will keep trying during the period of 1 hour. After that,
	will return None.
	'''

	global url
	try:
		html = urllib2.urlopen(url).read()

	# 
	except urllib2.URLError as e:
		if (errors+1 >= 100):
			print url, 'caused an error:'
			print e.reason
			html = None
		else:
			sleep(36)
			html = download_html(errors+1)
	return html

def send_email(first = False):
	e = MIMEMultipart()
	e['From'] = my_email
	e['To'] = my_email
	if first: # Notifies that the scipt is working
		e['Subject'] = 'Script is active'
		content = MIMEText("The script is now active")
		e.attach(content)
		msg = e.as_string()
	else: # Notifies that changes occurred
		e['Subject'] = '' # Email "Subject"
		content = '' # Insert the content of the email here
		e.attach(MIMEText(content))
		msg = e.as_string()
	server.sendmail(my_email, my_email, msg)
	print 'Email sent to %s' % my_email

send_email(True)

while True:
	interval = 60
	sleep(interval) # Verifies every X seconds
	print 'Trying at: ' + str(datetime.now())
	html = download_html()
	if (html is None):
		raise Exception('Could not continue after 1 hour trying')
	elif (previous is None):
		previous = html
	else:
		current = html
		if (previous != current):
			send_email()
			previous = current # updates page version