def __init__ ( self, filename=None ):

    if filename==None:
      #self.fd = tempfile.NamedTemporaryFile( 'w+b', bufsize=-1, suffix=".hdf5", dir=ocpcaprivate.ssd_log_location, delete="False" )
      self.fd.close()
    else:
      self.fd = open('filename', 'rb+')
   
    try :
      self.h5fd = h5py.File( str(self.fd.name), mode='a', driver="core", backing_store=True )
    except IOError,e:
      print "File Does not Exist. {}".format(e)
Intiliaze the Data Structure
dataset/ETHPy150Open neurodata/ndstore/ocpca/datastream.py/DataStream.__init__