From 3e57a662438383bb52a6cc249b9f87c67de76753 2012-02-08 21:35:24
From: MinRK <benjaminrk@gmail.com>
Date: 2012-02-08 21:35:24
Subject: [PATCH] ignore IOPub messages with no parent.

Generally caused by print statements or warnings from before the first execution.

---

diff --git a/IPython/parallel/client/client.py b/IPython/parallel/client/client.py
index 82e1e0a..e7fd57d 100644
--- a/IPython/parallel/client/client.py
+++ b/IPython/parallel/client/client.py
@@ -726,6 +726,10 @@ class Client(HasTraits):
             if self.debug:
                 pprint(msg)
             parent = msg['parent_header']
+            # ignore IOPub messages with no parent.
+            # Caused by print statements or warnings from before the first execution.
+            if not parent:
+                continue
             msg_id = parent['msg_id']
             content = msg['content']
             header = msg['header']