numpy - Automatically import modules when entering the python or ipython interpreter

Question

I find myself typing import numpy as np almost every single time I fire up the python interpreter. How do I set up the python or ipython interpreter so that numpy is automatically imported?

Answer 1

For ipython, there are two ways to achieve this. Both involve ipython's configuration directory which is located in ~/.ipython.

1. Create a custom ipython profile.
2. Or you can add a startup file to ~/.ipython/profile_default/startup/

For simplicity, I'd use option 2. All you have to do is place a .py or .ipy file in the ~/.ipython/profile_default/startup directory and it will automatically be executed. So you could simple place import numpy as np in a simple file and you'll have np in the namespace of your ipython prompt.

Option 2 will actually work with a custom profile, but using a custom profile will allow you to change the startup requirements and other configuration based on a particular case. However, if you'd always like np to be available to you then by all means put it in the startup directory.

For more information on ipython configuration. The docs have a much more complete explanation.