I’m reading the book, Web Scraping with Python which has the following function to retrieve external links found on a page:
#Retrieves a list of all external links found on a page
def getExternalLinks(bs, excludeUrl):
externalLinks = []
#Finds all links that start with "http" that do
#not contain the current URL
for link in bs.find_all('a', {'href' : re.compile('^(http|www)((?!'+excludeUrl+').)*$')}):
if link.attrs['href'] is not None:
if link.attrs['href'] not in externalLinks:
externalLinks.append(link.attrs['href'])
return externalLinks
The problem is that it does not work the way it should. When i run it using the URL: http://www.oreilly.com, it returns this:
bs = makeSoup('https://www.oreilly.com') # Makes a BeautifulSoup Object
getExternalLinks(bs, 'https://www.oreilly.com')
Output:
['https://www.oreilly.com',
'https://oreilly.com/sign-in.html',
'https://oreilly.com/online-learning/try-now.html',
'https://oreilly.com/online-learning/index.html',
'https://oreilly.com/online-learning/individuals.html',
'https://oreilly.com/online-learning/teams.html',
'https://oreilly.com/online-learning/enterprise.html',
'https://oreilly.com/online-learning/government.html',
'https://oreilly.com/online-learning/academic.html',
'https://oreilly.com/online-learning/pricing.html',
'https://www.oreilly.com/partner/reseller-program.html',
'https://oreilly.com/conferences/',
'https://oreilly.com/ideas/',
'https://oreilly.com/about/approach.html',
'https://www.oreilly.com/conferences/',
'https://conferences.oreilly.com/velocity/vl-ny',
'https://conferences.oreilly.com/artificial-intelligence/ai-eu',
'https://www.safaribooksonline.com/public/free-trial/',
'https://www.safaribooksonline.com/team-setup/',
'https://www.oreilly.com/online-learning/enterprise.html',
'https://www.oreilly.com/about/approach.html',
'https://conferences.oreilly.com/software-architecture/sa-eu',
'https://conferences.oreilly.com/velocity/vl-eu',
'https://conferences.oreilly.com/software-architecture/sa-ny',
'https://conferences.oreilly.com/strata/strata-ca',
'http://shop.oreilly.com/category/customer-service.do',
'https://twitter.com/oreillymedia',
'https://www.facebook.com/OReilly/',
'https://www.linkedin.com/company/oreilly-media',
'https://www.youtube.com/user/OreillyMedia',
'https://www.oreilly.com/emails/newsletters/',
'https://itunes.apple.com/us/app/safari-to-go/id881697395',
'https://play.google.com/store/apps/details?id=com.safariflow.queue']
Question:
Why are the first 16-17 entries considered “external links”? They belong to the same domain of http://www.oreilly.com.
2
Answers
there is a difference between these two:
hope you got my point.