Merge pull request #2209 from joshmay1/fiss_yield_copy

Add a `__deepcopy__` method to the deplete.FissionYield class

openmc/deplete/nuclide.py

@@ -13,7 +13,7 @@ try:
 except ImportError:
     import xml.etree.ElementTree as ET
 
-from numpy import empty, searchsorted
+import numpy as np
 
 from openmc.checkvalue import check_type
 
@@ -470,7 +470,7 @@ class FissionYieldDistribution(Mapping):
         shared_prod = set.union(*(set(x) for x in fission_yields.values()))
         ordered_prod = sorted(shared_prod)
 
-        yield_matrix = empty((len(energies), len(shared_prod)))
+        yield_matrix = np.empty((len(energies), len(shared_prod)))
 
         for g_index, energy in enumerate(energies):
             prod_map = fission_yields[energy]
@@ -560,7 +560,7 @@ class FissionYieldDistribution(Mapping):
             return None
 
         products = sorted(overlap)
-        indices = searchsorted(self.products, products)
+        indices = np.searchsorted(self.products, products)
 
         # coerce back to dictionary to pass back to __init__
         new_yields = {}
@@ -681,6 +681,11 @@ class FissionYield(Mapping):
         return "<{} containing {} products and yields>".format(
             self.__class__.__name__, len(self))
 
+    def __deepcopy__(self, memo):
+        result = FissionYield(self.products, self.yields.copy())
+        memo[id(self)] = result
+        return result
+
     # Avoid greedy numpy operations like np.float64 * fission_yield
     # converting this to an array on the fly. Force __rmul__ and
     # __radd__. See issue #1492

tests/unit_tests/test_deplete_nuclide.py

@@ -1,7 +1,7 @@
 """Tests for the openmc.deplete.Nuclide class."""
 
 import xml.etree.ElementTree as ET
-
+import copy
 import numpy as np
 import pytest
 from openmc.deplete import nuclide
@@ -335,3 +335,14 @@ def test_validate():
     assert "decay mode" in record[0].message.args[0]
     assert "0 reaction" in record[1].message.args[0]
     assert "1.0" in record[2].message.args[0]
+
+
+def test_deepcopy():
+    """Test deepcopying a FissionYield object"""
+    nuc = nuclide.FissionYield(products=("I129", "Sm149", "Xe135"), yields=np.array((0.001, 0.0003, 0.002)))
+    copied_nuc = copy.deepcopy(nuc)
+    # Check the deepcopy equals the original
+    assert copied_nuc == nuc
+    # Mutate the original and verify the copy remains intact
+    nuc *= 2
+    assert copied_nuc != nuc