Fixed #4062, added import for _ast.__version__ to ast to match the documented behavior.
diff --git a/Lib/ast.py b/Lib/ast.py
index ab6eed4..6d92edd 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -26,6 +26,7 @@
     :license: Python License.
 """
 from _ast import *
+from _ast import __version__
 
 
 def parse(expr, filename='<unknown>', mode='exec'):