title: Moving files under python
body: <p>I'm confused with file moving under python.
  Under windows commandline, if i have directory c:\a and a directory c:\b, i can do</p>
  
  <pre><code>move c:\a c:\b
  </code></pre>
  
  <p>which moves a to b result is directory structure c:\b\a</p>
  
  <p>If I try this with os.rename or shutil.move:</p>
  
  <pre><code>os.rename("c:/a", "c:/b")
  </code></pre>
  
  <p>I get </p>
  
  <pre><code>WindowsError: [Error 17] Cannot create a file when that file already exists
  </code></pre>
  
  <p>If I move a single file under c:\a, it works.</p>
  
  <p>In python how do i move a directory to another existing directory?</p>