Merge pull request #93 from JoonaTuovinen/master

Addresses #86

pysd/pysd.py

@@ -107,16 +107,22 @@ def __init__(self, components):
         self.components = components
 
     def __str__(self):
-
         """ Return model source file """
 
-        # rename the python file to have the original mdl extension.
-        # This needs to be changed should the python file name generation
-        # (from the Vensim model filename) change
-        # JPH: Maybe we should attach the original and the python filenames
-        # to the model object as attributes?
-        fn = str(self.components.__file__).split('.')[0] + '.mdl'
-        return fn
+        # JT: Might be helpful to return not only the source file, but
+        # also how the instance differs from that source file. This
+        # would give a more accurate view of the current model.
+        return self.mdl_file
+
+    @property
+    def py_model_file(self):
+        """ Return model's python file """
+        return str(self.components.__file__)
+
+    @property
+    def mdl_file(self):
+        """ Return model's vensim source file """
+        return self.py_model_file.replace('.py', '.mdl')
 
     def run(self, params=None, return_columns=None, return_timestamps=None,
             initial_condition='original'):

tests/unit_test_pysd.py

@@ -362,5 +362,15 @@ def test_restart_cache(self):
         self.assertEqual(new, 345)
         self.assertNotEqual(old, new)
 
+    def test_py_model_file(self):
+        """Addresses https://github.com/JamesPHoughton/pysd/issues/86"""
+        import pysd
+        model = pysd.read_vensim(test_model)
+        self.assertEqual(model.py_model_file, test_model.replace('.mdl', '.py'))
 
+    def test_mdl_file(self):
+        """Relates to https://github.com/JamesPHoughton/pysd/issues/86"""
+        import pysd
+        model = pysd.read_vensim(test_model)
+        self.assertEqual(model.mdl_file, test_model)