Merge branch 'rjkoch-fix_list_handling'

* adjust for fixup in diffpy.structure
* wrapped dictionary .keys() call in list
* wrapped dictionary .values() call in list

Resolve #60.

Author: pavoljuhas

src/diffpy/srfit/fitbase/fitrecipe.py

@@ -179,7 +179,7 @@ def addContribution(self, con, weight = 1.0):
 
     def setWeight(self, con, weight):
         """Set the weight of a FitContribution."""
-        idx = self._contributions.values().index(con)
+        idx = list(self._contributions.values()).index(con)
         self._weights[idx] = weight
         return
 

src/diffpy/srfit/fitbase/fitresults.py

@@ -349,7 +349,7 @@ def formatResults(self, header = "", footer = "", update = False):
 
         ## Per-FitContribution results
         if len(self.conresults) > 1:
-            keys = self.conresults.keys()
+            keys = list(self.conresults.keys())
             keys.sort(key=numstr)
 
             lines.append("")

src/diffpy/srfit/tests/testpdf.py

@@ -270,11 +270,6 @@ def test_pickling(self):
         self.assertTrue(numpy.array_equal(res1, pc2.residual()))
         return
 
-    # TODO: remove after fixup release of diffpy.structure
-    import sys
-    if sys.version_info >= (3, 7):
-        test_pickling = unittest.expectedFailure(test_pickling)
-
 # End of class TestPDFContribution
 
 # ----------------------------------------------------------------------------