title: Simultaneously indexing fields and a slice using `h5py`
body: <p>Given an H5Py file of the following type</p>
  
  <pre><code>In [41]: d.shape
  Out[41]: (37450461,)
  
  In [42]: d.dtype 
  Out[42]: dtype([('transaction', '&lt;i8'), ('sender', '&lt;i8'), ('recipient', '&lt;i8'),
                  ('timestamp', '&lt;i8'), ('value', '&lt;f8')])
  </code></pre>
  
  <p>I would like to get out a few fields over just a few entries.  I'm looking for something like the following:</p>
  
  <pre><code>In [43]: d[['timestamp', 'value'], :5]
  </code></pre>
  
  <p>Sadly this raises an error.  I can break the query up into multiple parts and it works:</p>
  
  <pre><code>In [46]: d[:5][['timestamp', 'value']]
  </code></pre>
  
  <p>But this is inefficient.</p>
  
  <h3>Question</h3>
  
  <p>Is there any way to efficiently select a few fields and a few entries from a structured array stored in HDF5 using <code>h5py</code>?</p>