Index: Lib/ast.py
===================================================================
--- Lib/ast.py	(revision 68482)
+++ Lib/ast.py	(working copy)
@@ -64,6 +64,13 @@
         elif isinstance(node, Name):
             if node.id in _safe_names:
                 return _safe_names[node.id]
+        elif isinstance(node, BinOp) and \
+             isinstance(node.op, Add):
+            left = _convert(node.left)
+            right = _convert(node.right)
+            if isinstance(left, (int, long, float)) and \
+               isinstance(right, complex):
+                return left + right
         raise ValueError('malformed string')
     return _convert(node_or_string)