IPython: load extension automatically upon start

Question

In IPython, I can load a custom extension using simple command:

%load_ext physics

This will load the file ~/.ipython/extensions/physics.py.

How can I tell IPython to load the extension automatically on startup?

I have added the line to /.ipython/profile_default/startup/import.py, but that does not work:

from numpy import *

%load_ext physics

When I start IPython, I get folowing error:

File "~/.ipython/profile_default/startup/import.py", line 17
%load_ext physics
^
SyntaxError: invalid syntax

Answer 1

From the IPython documentation:

Using extensions

To load an extension while IPython is running, use the %load_ext magic:

In [1]: %load_ext myextension

To load it each time IPython starts, list it in your configuration file:

c.InteractiveShellApp.extensions = [
    'myextension'
]

Hope that helps