title: Close an open h5py data file
body: <p>In our lab we store our data in <code>hdf5</code> files trough the python package <code>h5py</code>.</p>
  
  <p>At the beginning of an experiment we create an <code>hdf5</code> file and store array after array of array of data in the file (among other things). When an experiment fails or is interrupted the file is not correctly closed. 
  Because our experiments run from <code>iPython</code> the reference to the data object remains (somewhere) in memory. </p>
  
  <p>Is there a way to scan for all open h5py data objects and close them? </p>