Please copy and paste the following code in Data Science Experience's notebook.
# Import libraries
import urllib2
import re
# Pull html
website = urllib2.urlopen("http://clasificados.eltiempo.com/avisos/vivienda?query=Apartamento")
html = website.read()
# Extract all the links
links = re.findall('href=.(/anuncio/aviso-vivienda.*?)"', html)
print links[1]