View the original notebook on nbviewer
Connecting to an existing IPython kernel using the Qt Console¶
The Frontend/Kernel Model¶
The traditional IPython (ipython) consists of a single process that
combines a terminal based UI with the process that runs the users code.
While this traditional application still exists, the modern Jupyter consists of two processes:
- Kernel: this is the process that runs the users code.
- Frontend: this is the process that provides the user interface where the user types code and sees results.
Jupyter currently has 3 frontends:
- Terminal Console (
ipython console) - Qt Console (
ipython qtconsole) - Notebook (
ipython notebook)
The Kernel and Frontend communicate over a ZeroMQ/JSON based messaging
protocol, which allows multiple Frontends (even of different types) to
communicate with a single Kernel. This opens the door for all sorts of
interesting things, such as connecting a Console or Qt Console to a
Notebook’s Kernel. For example, you may want to connect a Qt console to
your Notebook’s Kernel and use it as a help browser, calling ?? on
objects in the Qt console (whose pager is more flexible than the one in
the notebook).
This Notebook describes how you would connect another Frontend to a Kernel that is associated with a Notebook.
Manual connection¶
To connect another Frontend to a Kernel manually, you first need to find
out the connection information for the Kernel using the
%connect_info magic:
%connect_info
You can see that this magic displays everything you need to connect to this Notebook’s Kernel.
Automatic connection using a new Qt Console¶
You can also start a new Qt Console connected to your current Kernel by
using the %qtconsole magic. This will detect the necessary
connection information and start the Qt Console for you automatically.
a = 10
%qtconsole