Merge pull request #1625 from dota17/issue#1540

Fix creating attribute with Empty

h5py/_hl/base.py

@@ -481,7 +481,7 @@ class Empty(object):
     size = None
 
     def __init__(self, dtype):
-        self.dtype = dtype
+        self.dtype = np.dtype(dtype)
 
     def __eq__(self, other):
         if isinstance(other, Empty) and self.dtype == other.dtype:

h5py/tests/test_attrs.py

@@ -194,6 +194,15 @@ def test_named(self):
         self.assertEqual(htype, htype2)
         self.assertTrue(htype.committed())
 
+    def test_empty(self):
+        # https://github.com/h5py/h5py/issues/1540
+        """ Create attribute with h5py.Empty value
+        """
+        self.f.attrs.create('empty', h5py.Empty('f'))
+        self.assertEqual(self.f.attrs['empty'], h5py.Empty('f'))
+
+        self.f.attrs.create('empty', h5py.Empty(None))
+        self.assertEqual(self.f.attrs['empty'], h5py.Empty(None))
 
 class TestMutableMapping(BaseAttrs):
     '''Tests if the registration of AttributeManager as a MutableMapping

news/empty-constructor.rst

@@ -0,0 +1,29 @@
+New features
+------------
+
+* <news item>
+
+Deprecations
+------------
+
+* <news item>
+
+Exposing HDF5 functions
+-----------------------
+
+* <news item>
+
+Bug fixes
+---------
+
+* Fix creating attribute with Empty by converting its dtype to a numpy dtype.
+
+Building h5py
+-------------
+
+* <news item>
+
+Development
+-----------
+
+* <news item>