title: Using help and pydoc to list python modules not working
body: <p>I'm trying to find out what modules I have installed for python</p>
  
  <p>from: <a href="https://stackoverflow.com/questions/739993/get-a-list-of-installed-python-modules">this thread</a>  </p>
  
  <p>I've tried </p>
  
  <pre><code>&gt;&gt;&gt; help('modules')
  no Python documentation found for 'modules'
  
  &gt;&gt;&gt; pydoc modules
    File "&lt;stdin&gt;", line 1
      pydoc modules
                  ^
  SyntaxError: invalid syntax
  </code></pre>
  
  <p>However, this works</p>
  
  <pre><code>&gt;&gt;&gt; help('numpy')
  </code></pre>
  
  <p>along with any other module I know I have installed.</p>
  
  <p>This <em>does</em> return the modules, but <strong>is there a way to fix my help documentation?</strong></p>
  
  <pre><code>from pkgutil import iter_modules
  for a in iter_modules():
      print a
  </code></pre>
  
  <p><strong>Edit</strong></p>
  
  <p>I installed the 64 bit python 2.7 through the enthought python distribution on Mac OS mtn lion</p>
  
  <p>running pydoc in shell:</p>
  
  <pre><code>$ pydoc modules
  no Python documentation found for 'modules'
  </code></pre>