title: how do I add a pandas object (e.g. DataFrame) to a group within an HDF file?
body: <p>Suppose I have an HDF5 file (myHDF.h5) with a hierarchy of groups, something like:</p>
  
  <pre><code>/root/groupA
       /groupB
  </code></pre>
  
  <p>Now I want to add a <code>DataFrame</code> (myFrame) to the groupA (along with some other objects such as dictionaries). How do I do that? If I open my HDF.h5 with <code>pandas.io.HDFStore</code>: </p>
  
  <pre><code>store = pandas.io.HDFStore('myHDF.h5')
  </code></pre>
  
  <p>and then try:</p>
  
  <pre><code>store['groupA']['myFrame'] = myFrame
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>AttributeError: Attribute 'pandas_type' does not exist in node: '/groupA'
  </code></pre>
  
  <p>What is the proper way to do this? </p>