None is represented differently in <3.4

Author: dflook

src/python_minifier/transforms/implicit_return_none.py

@@ -1,13 +1,19 @@
 import ast
+import sys
 
 from python_minifier.util import is_ast_node
 
 
 def implicit_return_none(node):
 
-    if isinstance(node, ast.Return) and is_ast_node(node.value, 'NameConstant') and node.value.value is None:
-        # explicit return None
-        node.value = None
+    if isinstance(node, ast.Return):
+        if sys.version_info < (3, 4) and is_ast_node(node.value, 'Name') and node.value.id == 'None':
+            # explicit return None
+            node.value = None
+
+        elif sys.version_info >= (3, 4) and is_ast_node(node.value, 'NameConstant') and node.value.value is None:
+            # explicit return None
+            node.value = None
 
     for child in ast.iter_child_nodes(node):
         implicit_return_none(child)