Fix Python 3 compatibility of PageIterator#key_names (pynamodb#535)

zetaben · garrettheel · commit ed7f205ea0b4 · 2018-08-30T14:47:10.000+10:00
diff --git a/pynamodb/pagination.py b/pynamodb/pagination.py
@@ -1,4 +1,5 @@
 import time
+import six
 from pynamodb.constants import (CAMEL_COUNT, ITEMS, LAST_EVALUATED_KEY, SCANNED_COUNT,
                                 CONSUMED_CAPACITY, TOTAL, CAPACITY_UNITS)
 
@@ -119,7 +120,7 @@ def key_names(self):
             return self._last_evaluated_key.keys()
 
         # Use the table meta data to determine the key attributes
-        table_meta = self._operation.im_self.get_meta_table()
+        table_meta = six.get_method_self(self._operation).get_meta_table()
         return table_meta.get_key_names(self._kwargs.get('index_name'))
 
     @property
