title: bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?
body: <pre><code>...
  soup = BeautifulSoup(html, "lxml")
  File "/Library/Python/2.7/site-packages/bs4/__init__.py", line 152, in __init__
  % ",".join(features))
  bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?
  </code></pre>
  
  <p>The above outputs on my Terminal. I am on Mac OS 10.7.x. I have Python 2.7.1, and followed <a href="http://www.gregreda.com/2013/03/03/web-scraping-101-with-python/">this tutorial</a> to get Beautiful Soup and lxml, which both installed successfully and work with a separate test file <a href="http://web.engr.illinois.edu/~shauk2/testWebScrape.py">located here</a>. In the Python script that causes this error, I have included this line:
      <code>from pageCrawler import comparePages</code>
  And in the pageCrawler file I have included the following two lines:
      <code>from bs4 import BeautifulSoup</code>
      <code>from urllib2 import urlopen</code></p>
  
  <p>Any help in figuring out what the problem is and how it can be solved would much be appreciated.</p>