added function and corresponding test for getting fractional occupancy from file.

solventmapcreator/io/solventxmlreader.py

@@ -23,6 +23,13 @@ PHASE_NAMESPACE_DICT = {"phase":"http://www-hunter.ch.cam.ac.uk/PhaseSchema",
 
 IDEAL_MAX_SSIP_CONCENTRATION_MOLAR = 300.0
 
+def get_fractional_occupancy_for_solvent_from_file(solvent_filename, solvent_id):
+    """This reads inthe file and extracts the solvent information, and returns
+    the fractional occupancy contribution from the solvent.
+    """
+    solvent_list_element = read_element_tree(solvent_filename)
+    return get_fractional_occupancy_for_solvent(solvent_list_element, solvent_id)
+
 def get_fractional_occupancy_for_solvent(solvent_list_element, solvent_id):
     """This extracts the solvent XML, and calculates the fractional occupancy
     contribution for the solvent.

solventmapcreator/test/iotest/solventxmlreadertest.py

@@ -31,6 +31,12 @@ class SolventXMLReaderTestCase(unittest.TestCase):
         del self.solvent_list_xml
         del self.water_solvent_element
         del self.water_molecule_element
+    def test_get_fractional_occupancy_for_solvent_from_file(self):
+        """Test to see if expected value is returned.
+        """
+        expected_value = 55.35 * 4.0 /300.0
+        actual_value = solventxmlreader.get_fractional_occupancy_for_solvent_from_file("resources/watersolvent.xml", "water")
+        self.assertAlmostEqual(expected_value, actual_value)
     def test_get_fractional_occupancy_for_solvent(self):
         """Test to see if expected fractional occupancy is returned.
         """