Merge pull request microsoft#1455 from VandersypenQutech/fix/hdf5

add flush option to hdf5 write_metadata

qcodes/data/hdf5_format.py

@@ -290,6 +290,10 @@ def write_metadata(self, data_set, io_manager=None, location=None, read_first=Tr
         metadata_group = data_set._h5_base_group.create_group('metadata')
         self.write_dict_to_hdf5(data_set.metadata, metadata_group)
 
+        # flush ensures buffers are written to disk
+        # (useful for ensuring openable by other files)
+        data_set._h5_base_group.file.flush()
+
     def _read_list_group(self, entry_point, list_type):
         d = {}
         self.read_dict_from_hdf5(data_dict=d,

qcodes/tests/test_hdf5formatter.py

@@ -218,16 +218,10 @@ def test_dataset_closing(self):
         data = DataSet1D(location=self.loc_provider, name='test_closing')
         self.formatter.write(data, flush=False)
         fp = data._h5_base_group.filename
-        fp2 = fp[:-5]+'_2.hdf5'
-        copy(fp, fp2)
-        # Raises an error because the file was open and not flushed
-        # This tests if this way of testing works
-        with self.assertRaises(OSError):
-            F2 = h5py.File(fp2)
         self.formatter.close_file(data)
         fp3 = fp[:-5]+'_3.hdf5'
         copy(fp, fp3)
-        # Should now not raise an error because the file was properly closed
+        # Should not raise an error because the file was properly closed
         F3 = h5py.File(fp3)
 
     def test_dataset_flush_after_write(self):
@@ -244,11 +238,7 @@ def test_dataset_finalize_closes_file(self):
         # closing before file is written should not raise error
         self.formatter.write(data, flush=False)
         fp = data._h5_base_group.filename
-        fp2 = fp[:-5]+'_2.hdf5'
-        copy(fp, fp2)
-        # Raises an error because the file was still open
-        with self.assertRaises(OSError):
-            F2 = h5py.File(fp2)
+
         # Attaching the formatter like this should not be neccesary
         data.formatter = self.formatter
         data.finalize()