“Grastrando correos electrónicos con Python” Código de respuesta

Grastrando correos electrónicos con Python

import re
import requests
import requests.exceptions
from urllib.parse import urlsplit
from collections import deque
from bs4 import BeautifulSoup

# starting url. replace google with your own url.
starting_url = 'http://www.miet.ac.in'

# a queue of urls to be crawled
unprocessed_urls = deque([starting_url])

# set of already crawled urls for email
processed_urls = set()

# a set of fetched emails
emails = set()

# process urls one by one from unprocessed_url queue until queue is empty
while len(unprocessed_urls):

    # move next url from the queue to the set of processed urls
    url = unprocessed_urls.popleft()
    processed_urls.add(url)

    # extract base url to resolve relative links
    parts = urlsplit(url)
    base_url = "{0.scheme}://{0.netloc}".format(parts)
    path = url[:url.rfind('/')+1] if '/' in parts.path else url

    # get url's content
    print("Crawling URL %s" % url)
    try:
        response = requests.get(url)
    except (requests.exceptions.MissingSchema, requests.exceptions.ConnectionError):
        # ignore pages with errors and continue with next url
        continue

    # extract all email addresses and add them into the resulting set
    # You may edit the regular expression as per your requirement
    new_emails = set(re.findall(r"[a-z0-9\.\-+_]+@[a-z0-9\.\-+_]+\.[a-z]+", response.text, re.I))
    emails.update(new_emails)
    print(emails)
    # create a beutiful soup for the html document
    soup = BeautifulSoup(response.text, 'lxml')

    # Once this document is parsed and processed, now find and process all the anchors i.e. linked urls in this document
    for anchor in soup.find_all("a"):
        # extract link url from the anchor
        link = anchor.attrs["href"] if "href" in anchor.attrs else ''
        # resolve relative links (starting with /)
        if link.startswith('/'):
            link = base_url + link
        elif not link.startswith('http'):
            link = path + link
        # add the new url to the queue if it was not in unprocessed list nor in processed list yet
        if not link in unprocessed_urls and not link in processed_urls:
            unprocessed_urls.append(link)