Merge pull request #2230 from shimwell/adding_material_names_to_DAGMCUniverse

openmc/universe.py

@@ -647,6 +647,11 @@ class DAGMCUniverse(UniverseBase):
     bounding_box : 2-tuple of numpy.array
         Lower-left and upper-right coordinates of an axis-aligned bounding box
         of the universe.
+    material_name : list of str
+        Return a sorted list of materials names that are contained within the
+        DAGMC h5m file. This is useful when naming openmc.Material() objects
+        as each material name present in the DAGMC h5m file must have a
+        matching openmc.Material() with the same name.
 
         .. versionadded:: 0.13.1
     """
@@ -699,6 +704,21 @@ class DAGMCUniverse(UniverseBase):
     def auto_mat_ids(self):
         return self._auto_mat_ids
 
+    @property
+    def material_names(self):
+        dagmc_file_contents = h5py.File(self.filename)
+        material_tags_hex=dagmc_file_contents['/tstt/tags/NAME'].get('values')
+        material_tags_ascii=[]
+        for tag in material_tags_hex:
+            candidate_tag = tag.tobytes().decode().replace('\x00', '')
+            # tags might be for temperature or reflective surfaces
+            if candidate_tag.startswith('mat:'):
+                # removes first 4 characters as openmc.Material name should be
+                # set without the 'mat:' part of the tag
+                material_tags_ascii.append(candidate_tag[4:])
+
+        return sorted(set(material_tags_ascii))
+
     @auto_mat_ids.setter
     def auto_mat_ids(self, val):
         cv.check_type('DAGMC automatic material ids', val, bool)

tests/unit_tests/dagmc/test_bounds.py

@@ -71,3 +71,12 @@ def test_bounded_universe(request):
     surfaces = list(cells[0][1].region.get_surfaces().items())
     assert surfaces[0][1].type == "sphere"
     assert surfaces[0][1].id == 43
+
+
+def test_material_names(request):
+    """Checks that the DAGMCUniverse.material_names() returns a list of the
+    name present in the dagmc.h5m file in the expected order"""
+
+    u = openmc.DAGMCUniverse(Path(request.fspath).parent / "dagmc.h5m")
+
+    assert u.material_names == ['41', 'Graveyard', 'no-void fuel']