added warning for retrieving from groups

Author: dacoex

doc/source/io.rst

@@ -2812,10 +2812,12 @@ everything in the sub-store and BELOW, so be *careful*.
        /foo/bar/bah (Group) ''
        children := ['block0_items' (Array), 'axis1' (Array), 'axis0' (Array), 'block0_values' (Array)]
        
-       
-       
+    Use explicit string based keys
 
+    .. ipython:: python
     
+       bah = store['foo/bar/bah']
+       
 
 Storing Types
 '''''''''''''