Write GenericFunction.__init__ in a different way

geoalchemy2/functions.py

@@ -91,22 +91,19 @@ class ST_TransScale(GenericFunction):
 
     def __init__(self, *args, **kwargs):
         expr = kwargs.pop('expr', None)
+        args = list(args)
         if expr is not None:
-            args = (expr,) + args
-        new_args = []
-        for elem in args:
+            args = [expr] + args
+        for idx, elem in enumerate(args):
             if isinstance(elem, elements.HasFunction):
                 if elem.extended:
                     func_name = elem.geom_from_extended_version
                     func_args = [elem.data]
                 else:
                     func_name = elem.geom_from
                     func_args = [elem.data, elem.srid]
-                new_arg = getattr(functions.func, func_name)(*func_args)
-            else:
-                new_arg = elem
-            new_args.append(new_arg)
-        functions.GenericFunction.__init__(self, *new_args, **kwargs)
+                args[idx] = getattr(functions.func, func_name)(*func_args)
+        functions.GenericFunction.__init__(self, *args, **kwargs)
 
 
 # Functions are classified as in the PostGIS doc.