Python 3 preparation: update calls to dict methods. Tool-assisted patch. Changes of iterkeys / itervalues / iteritems to keys / values / items are fully automated, but may make things less efficient in Python 2. Automated tools want to add list() around many calls to keys / values / items, but I thought most such list() additions were unnecessary because it seemed the result of keys / values / items was just iterated over while the set of dict keys remained unchanged, rather than used in a way requiring an actual list, or used while the set of keys in the dict could change. It's quite possible I missed some cases where list() was really needed, or left in some unnecessary list() calls. In cases where list() was only needed because the resulting list was then sorted in-place, I changed the code to use calls to sorted().

--- a/test/memorydb.py	Tue Jul 24 23:03:35 2018 +0000
+++ b/test/memorydb.py	Tue Jul 24 23:04:42 2018 +0000
@@ -134,7 +134,7 @@
     def set(self, infoid, **newvalues):
         self[infoid].update(newvalues)
     def list(self):
-        return self.keys()
+        return list(self.keys())
     def destroy(self, infoid):
         del self[infoid]
     def commit(self):
@@ -290,9 +290,7 @@
 
     def getclasses(self):
         """Return a list of the names of all existing classes."""
-        l = self.classes.keys()
-        l.sort()
-        return l
+        return sorted(self.classes.keys())
 
     def getclass(self, classname):
         """Get the Class object representing a particular class.