use 16 length key

Author: jreback

pandas/tools/hashing.py

@@ -78,7 +78,7 @@ def hash_array(vals):
 
         # we want to stringify
         # then apply a consistent hashing scheme
-        vals = _hash.hash_object_array(vals, 'foo')
+        vals = _hash.hash_object_array(vals, '0123456789123456')
 
     # Then, redistribute these 64-bit ints within the space of 64-bit ints
     vals ^= vals >> 30