fixed readability of shallow dict copy
@@ -136,7 +136,7 @@ class Descriptor(collections.MutableMapping):
def _remove_none_keys(desc):
- for key in {k: v for k, v in desc.items()}:
+ for key in dict(desc.items()):
if isinstance(desc[key], Descriptor):
desc[key].remove_none_keys()
if isinstance(desc[key], list):
