[Python] Add access to input data for Reaction objects

interfaces/cython/cantera/_cantera.pxd

@@ -358,6 +358,8 @@ cdef extern from "cantera/kinetics/Reaction.h" namespace "Cantera":
         string equation()
         string type()
         void validate() except +translate_exception
+        void getParameters(CxxAnyMap&) except +translate_exception
+        int reaction_type
         Composition reactants
         Composition products
         Composition orders
@@ -366,6 +368,7 @@ cdef extern from "cantera/kinetics/Reaction.h" namespace "Cantera":
         cbool duplicate
         cbool allow_nonreactant_orders
         cbool allow_negative_orders
+        CxxAnyMap input
 
     cdef cppclass CxxReaction2 "Cantera::Reaction2" (CxxReaction):
         CxxReaction2()

interfaces/cython/cantera/reaction.pyx

@@ -320,6 +320,17 @@ cdef class Reaction:
         def __set__(self, allow):
             self.reaction.allow_negative_orders = allow
 
+    property input_data:
+        """
+        Get input data for this reaction with its current parameter values,
+        along with any user-specified data provided with its input (YAML)
+        definition.
+        """
+        def __get__(self):
+            cdef CxxAnyMap params
+            self.reaction.getParameters(params)
+            return mergeAnyMap(params, self.reaction.input)
+
     def __repr__(self):
         return '<{}: {}>'.format(self.__class__.__name__, self.equation)
 

interfaces/cython/cantera/test/test_kinetics.py

@@ -842,6 +842,24 @@ class TestReaction(utilities.CanteraTest):
         self.assertIn('HO2', R[2].products)
         self.assertEqual(R[0].rate.temperature_exponent, 2.7)
 
+    def test_input_data_from_file(self):
+        R = self.gas.reaction(0)
+        data = R.input_data
+        self.assertEqual(data['type'], 'three-body')
+        self.assertEqual(data['efficiencies'],
+                         {'H2': 2.4, 'H2O': 15.4, 'AR': 0.83})
+        self.assertEqual(data['equation'], R.equation)
+
+    def test_input_data_from_scratch(self):
+        r = ct.ElementaryReaction({'O':1, 'H2':1}, {'H':1, 'OH':1})
+        r.rate = ct.Arrhenius(3.87e1, 2.7, 2.6e7)
+        data = r.input_data
+        self.assertEqual(data['rate-constant'],
+                         {'A': 3.87e1, 'b': 2.7, 'Ea': 2.6e7})
+        terms = data['equation'].split()
+        self.assertIn('O', terms)
+        self.assertIn('OH', terms)
+
     def test_elementary(self):
         r = ct.ElementaryReaction({'O':1, 'H2':1}, {'H':1, 'OH':1})
         r.rate = ct.Arrhenius(3.87e1, 2.7, 6260*1000*4.184)