Pass history request keys as **kwargs

IPython/kernel/zmq/kernelbase.py

@@ -416,19 +416,9 b' class KernelBase(Configurable):'
         return {'status': 'ok', 'data':{}, 'metadata':{}, 'found':False}
 
     def history_request(self, stream, ident, parent):
-        # We need to pull these out, as passing **kwargs doesn't work with
-        # unicode keys before Python 2.6.5.
         content = parent['content']
 
-        reply_content = self.do_history(content['hist_access_type'],
-                                        content['output'], content['raw'],
-                                        content.get('session', None),
-                                        content.get('start', None),
-                                        content.get('stop', None),
-                                        content.get('n', None),
-                                        content.get('pattern', None),
-                                        content.get('unique', False),
-                                       )
+        reply_content = self.do_history(**content)
 
         reply_content = json_clean(reply_content)
         msg = self.session.send(stream, 'history_reply',

docs/source/development/wrapperkernels.rst

@@ -128,7 +128,9 b' relevant section of the :doc:`messaging spec <messaging>`.'
 
    .. method:: do_history(hist_access_type, output, raw, session=None, start=None, stop=None, n=None, pattern=None, unique=False)
 
-     History access
+     History access. Only the relevant parameters for the type of history
+     request concerned will be passed, so your method definition must have defaults
+     for all the arguments shown with defaults here.
 
      .. seealso::