misc: sort categories using key function (#36515)

wcs/categories.py

@@ -66,21 +66,8 @@ class Category(XmlStorableObject):
 
     @classmethod
     def sort_by_position(cls, categories):
-        def cmp_position(x, y):
-            if x is None and y is None:
-                return 0
-            if y is None:
-                return -1
-            if x is None:
-                return 1
-            if x.position == y.position:
-                return 0
-            if x.position is None:
-                return 1
-            if y.position is None:
-                return -1
-            return cmp(x.position, y.position)
-        categories.sort(cmp_position)
+        # move categories with no defined position to the end
+        categories.sort(key=lambda x: x.position if x and x.position is not None else 10000)
 
     def remove_self(self):
         from .formdef import FormDef