fix test order dependence in pymatgen/analysis/tests/test_graphs.py

seems to have been caused by test_edge_editing(), now using deep copy instead in-place edit

Author: janosh

pymatgen/analysis/tests/test_graphs.py

@@ -528,12 +528,7 @@ def setUp(self):
         self.cyclohexene.add_edge(5, 14, weight=1.0)
         self.cyclohexene.add_edge(5, 15, weight=1.0)
 
-        butadiene = Molecule.from_file(
-            os.path.join(
-                PymatgenTest.TEST_FILES_DIR,
-                "graphs/butadiene.xyz",
-            )
-        )
+        butadiene = Molecule.from_file(os.path.join(PymatgenTest.TEST_FILES_DIR, "graphs/butadiene.xyz"))
         self.butadiene = MoleculeGraph.with_empty_graph(butadiene, edge_weight_name="strength", edge_weight_units="")
         self.butadiene.add_edge(0, 1, weight=2.0)
         self.butadiene.add_edge(1, 2, weight=1.0)
@@ -545,12 +540,7 @@ def setUp(self):
         self.butadiene.add_edge(3, 8, weight=1.0)
         self.butadiene.add_edge(3, 9, weight=1.0)
 
-        ethylene = Molecule.from_file(
-            os.path.join(
-                PymatgenTest.TEST_FILES_DIR,
-                "graphs/ethylene.xyz",
-            )
-        )
+        ethylene = Molecule.from_file(os.path.join(PymatgenTest.TEST_FILES_DIR, "graphs/ethylene.xyz"))
         self.ethylene = MoleculeGraph.with_empty_graph(ethylene, edge_weight_name="strength", edge_weight_units="")
         self.ethylene.add_edge(0, 1, weight=2.0)
         self.ethylene.add_edge(0, 2, weight=1.0)
@@ -669,16 +659,17 @@ def test_coordination(self):
         assert self.cyclohexene.get_coordination_of_site(0) == 4
 
     def test_edge_editing(self):
-        self.cyclohexene.alter_edge(0, 1, new_weight=0.0, new_edge_properties={"foo": "bar"})
-        new_edge = self.cyclohexene.graph.get_edge_data(0, 1)[0]
+        cyclohexene = copy.deepcopy(self.cyclohexene)
+        cyclohexene.alter_edge(0, 1, new_weight=0.0, new_edge_properties={"foo": "bar"})
+        new_edge = cyclohexene.graph.get_edge_data(0, 1)[0]
         assert new_edge["weight"] == 0.0
         assert new_edge["foo"] == "bar"
 
-        self.cyclohexene.break_edge(0, 1)
-        assert self.cyclohexene.graph.get_edge_data(0, 1) is None
+        cyclohexene.break_edge(0, 1)
+        assert cyclohexene.graph.get_edge_data(0, 1) is None
 
         # Replace the now-broken edge
-        self.cyclohexene.add_edge(0, 1, weight=1.0)
+        cyclohexene.add_edge(0, 1, weight=1.0)
 
     def test_insert_remove(self):
         mol_copy = copy.deepcopy(self.ethylene.molecule)