[Thermo] Fix slicing of SolutionArray objects

ischoegl · ischoegl · commit 2f8f68554758 · 2020-02-26T21:10:33.000-06:00
Fixes issue #804
diff --git a/interfaces/cython/cantera/composite.py b/interfaces/cython/cantera/composite.py
@@ -535,8 +535,12 @@ def __init__(self, phase, shape=(0,), states=None, extra=None):
 
     def __getitem__(self, index):
         states = self._states[index]
-        shape = states.shape[:-1]
-        return SolutionArray(self._phase, shape, states)
+        if isinstance(states, list):
+            rows = len(states)
+            return SolutionArray(self._phase, rows, states)
+        else:
+            shape = states.shape[:-1]
+            return SolutionArray(self._phase, shape, states)
 
     def __getattr__(self, name):
         if name in self._extra:
diff --git a/interfaces/cython/cantera/test/test_thermo.py b/interfaces/cython/cantera/test/test_thermo.py
@@ -1665,6 +1665,11 @@ def test_append(self):
         self.assertNear(states.P[-1], 1e4)
         self.assertNear(states.T[-1], 300)
 
+    def test_slice(self):
+        states = ct.SolutionArray(self.gas, 10)
+        arr = states[::2]
+        self.assertEqual(len(arr.T), 5)
+
     def test_purefluid(self):
         water = ct.Water()
         states = ct.SolutionArray(water, 5)
