new_contents: '''
  This script helps you download pdf files from remote destinations
  @author Gan Tu
  @version python 2
  '''
  
  import urllib
  import re
  
  # change this to the source url you are scrapping from
  source = 'http://inst.eecs.berkeley.edu/~ee16a/fa16/dis/'
  
  html = urllib.urlopen(source).read()
  
  # change this to your target regex
  regex = '<a href="(ans.+?.pdf)">.+</a>'
  pattern = re.compile(regex)
  titles = re.findall(pattern, html)
  
  for pdf in titles:
      url = source + pdf
      print "downloading " + pdf + "..."
      file = open(pdf, "w")
      file.write(urllib.urlopen(url).read())
      file.close()
      print "success."
subject: add tool for batch downloading pdfs