add ZMQShell.set_parent

coalesces all `set_parent` calls into one method.

IPython/kernel/zmq/ipkernel.py

@@ -374,17 +374,7 b' class Kernel(Configurable):'
             __builtin__.input = input
 
         # Set the parent message of the display hook and out streams.
-        shell.displayhook.set_parent(parent)
-        shell.display_pub.set_parent(parent)
-        shell.data_pub.set_parent(parent)
-        try:
-            sys.stdout.set_parent(parent)
-        except AttributeError:
-            pass
-        try:
-            sys.stderr.set_parent(parent)
-        except AttributeError:
-            pass
+        shell.set_parent(parent)
 
         # Re-broadcast our input for the benefit of listening clients, and
         # start computing output
@@ -590,17 +580,7 b' class Kernel(Configurable):'
 
         # Set the parent message of the display hook and out streams.
         shell = self.shell
-        shell.displayhook.set_parent(parent)
-        shell.display_pub.set_parent(parent)
-        shell.data_pub.set_parent(parent)
-        try:
-            sys.stdout.set_parent(parent)
-        except AttributeError:
-            pass
-        try:
-            sys.stderr.set_parent(parent)
-        except AttributeError:
-            pass
+        shell.set_parent(parent)
 
         # pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent)
         # self.iopub_socket.send(pyin_msg)

IPython/kernel/zmq/zmqshell.py

@@ -587,6 +587,20 b' class ZMQInteractiveShell(InteractiveShell):'
         )
         self.payload_manager.write_payload(payload)
     
+    def set_parent(self, parent):
+        """Set the parent header for associating output with its triggering input"""
+        self.displayhook.set_parent(parent)
+        self.display_pub.set_parent(parent)
+        self.data_pub.set_parent(parent)
+        try:
+            sys.stdout.set_parent(parent)
+        except AttributeError:
+            pass
+        try:
+            sys.stderr.set_parent(parent)
+        except AttributeError:
+            pass
+    
     #-------------------------------------------------------------------------
     # Things related to magics
     #-------------------------------------------------------------------------