python-scripts/08_basic_email_web_crawler.py

import requests
import re
try:
    from urllib.parse import urljoin
except ImportError:
    from urlparse import urljoin

# regex
email_re = re.compile(r'([\w\.,]+@[\w\.,]+\.\w+)')
link_re = re.compile(r'href="(.*?)"')


def crawl(url):

    result = set()

    req = requests.get(url)

    # Check if successful
    if(req.status_code != 200):
        return []

    # Find links
    links = link_re.findall(req.text)

    print("\nFound {} links".format(len(links)))

    # Search links for emails
    for link in links:

        # Get an absolute URL for a link
        link = urljoin(url, link)

        # Find all emails on current page
        result.update(email_re.findall(req.text))

    return result

if __name__ == '__main__':
    emails = crawl('http://www.realpython.com')

    print("\nScrapped e-mail addresses:")
    for email in emails:
        print(email)
    print("\n")