fixed 'if part:' typo, and I added a small hack to make SubpartDef work with a [0] reference (ugg)

direct/src/actor/Actor.py

@@ -79,6 +79,13 @@ class Actor(DirectObject, NodePath):
         def makeCopy(self):
             return Actor.SubpartDef(self.truePartName, PartSubset(self.subset))
 
+        def __getitem__(self,index):
+            if(index==0):
+                return self.truePartName
+            else:
+                return None
+            
+        
         def __repr__(self):
             return 'Actor.SubpartDef(%s, %s)' % (repr(self.truePartName), repr(self.subset))
 
@@ -938,7 +945,7 @@ class Actor(DirectObject, NodePath):
 
         truePartName = self.__subpartDict.get(partName, [partName])[0]
         partDef = partBundleDict.get(truePartName)
-        if part:
+        if partDef:
             bundle = partDef.partBundle.node().getBundle()
         else:
             Actor.notify.warning("no part named %s!" % (partName))