Merge pull request #2200 from shimwell/adding_element_filter_to_get_nuclides_without_sorting

added element filter to get_nuclide

openmc/material.py

@@ -795,16 +795,33 @@ class Material(IDManagerMixin):
 
         return sorted({re.split(r'(\d+)', i)[0] for i in self.get_nuclides()})
 
-    def get_nuclides(self):
-        """Returns all nuclides in the material
+    def get_nuclides(self, element: Optional[str] = None):
+        """Returns a list of all nuclides in the material, if the element
+        argument is specified then just nuclides of that element are returned.
+
+        Parameters
+        ----------
+        element : str
+            Specifies the element to match when searching through the nuclides
 
         Returns
         -------
         nuclides : list of str
             List of nuclide names
-
         """
-        return [x.name for x in self._nuclides]
+
+        matching_nuclides = []
+        if element:
+            for nuclide in self._nuclides:
+                if re.split(r'(\d+)', nuclide.name)[0] == element:
+                    if nuclide.name not in matching_nuclides:
+                        matching_nuclides.append(nuclide.name)
+        else:
+            for nuclide in self._nuclides:
+                if nuclide.name not in matching_nuclides:
+                    matching_nuclides.append(nuclide.name)
+                        
+        return matching_nuclides
 
     def get_nuclide_densities(self):
         """Returns all nuclides in the material and their densities

tests/unit_tests/test_material.py

@@ -299,6 +299,23 @@ def test_isotropic():
     assert m2.isotropic == ['H1']
 
 
+def test_get_nuclides():
+    mat = openmc.Material()
+
+    mat.add_nuclide('Li6', 1.0)
+    assert mat.get_nuclides() == ['Li6']
+    assert mat.get_nuclides(element='Li') == ['Li6']
+    assert mat.get_nuclides(element='Be') == []
+
+    mat.add_element('Li', 1.0)
+    assert mat.get_nuclides() == ['Li6', 'Li7']
+    assert mat.get_nuclides(element='Be') == []
+
+    mat.add_element('Be', 1.0)
+    assert mat.get_nuclides() == ['Li6', 'Li7', 'Be9']
+    assert mat.get_nuclides(element='Be') == ['Be9']
+
+
 def test_get_elements():
     # test that zero elements exist on creation
     m = openmc.Material()