[Cython/Reactor] Add Reactor keyword argument 'volume'

interfaces/cython/cantera/reactor.pyx

@@ -12,7 +12,7 @@ cdef class ReactorBase:
         self.rbase = newReactor(stringify(self.reactor_type))
 
     # The signature of this function causes warnings for Sphinx documentation
-    def __init__(self, ThermoPhase contents=None, name=None):
+    def __init__(self, ThermoPhase contents=None, name=None, *, volume=None):
         self._inlets = []
         self._outlets = []
         self._walls = []
@@ -26,6 +26,9 @@ cdef class ReactorBase:
             n = reactor_counts[self.reactor_type]
             self.name = '{0}_{1}'.format(self.reactor_type, n)
 
+        if volume is not None:
+            self.volume = volume
+
     def __dealloc__(self):
         del self.rbase
 

interfaces/cython/cantera/test/test_reactor.py

@@ -50,6 +50,13 @@ class TestReactor(utilities.CanteraTest):
         self.assertNear(R.T, 300)
         self.assertEqual(len(R.kinetics.net_production_rates), g.n_species)
 
+    def test_volume(self):
+        R = self.reactorClass(volume=11)
+        self.assertEqual(R.volume, 11)
+
+        R.volume = 9
+        self.assertEqual(R.volume, 9)
+
     def test_names(self):
         self.make_reactors()