title: How to read HDF5 files that have only datasets (no groups) using h5py?
body: <p>I have HDF5 files that I would like to open using the Python module h5py (in Python 2.7). </p>
  
  <p>This is easy when I have a file with groups and datasets:</p>
  
  <pre><code>import h5py as hdf
  
  with hdf.File(relative_path_to_file, 'r') as f:
      my_data = f['a_group']['a_dataset'].value
  </code></pre>
  
  <p>However, in my current situation I do not have groups. There are only datasets. Unfortunately, I cannot access my data no matter what I try. None of the following work (all break with KeyErrors or ValueErrors):</p>
  
  <pre><code>my_data = f['a_dataset'].value #KeyError
  
  my_data = f['/a_dataset'].value #KeyError
  
  my_data = f['/']['a_dataset'].value #KeyError
  
  my_data = f['']['a_dataset'].value #ValueError
  
  my_data = f['.']['a_dataset'].value #KeyError
  </code></pre>
  
  <p>I can remake my files to have a group if there is no solution. It really seems like there should be a solution, though...</p>
  
  <p>It seems like h5py is not seeing any keys:</p>
  
  <pre><code>f.keys()
  []
  </code></pre>