Shorter Hacks 16: IPython Autoreload

When developing some python code and testing it in IPython, I love the autoreload feature of IPython. When enabled it will reload imported modules automatically. So you will always use the newest version of your code. It even patches modifications on class methods into existing class instances. To enable it first load it with %load_ext autoreload, then enable it with %autoreload 2 – See the documentation for explanations of the options and how to autoreload only selected imports. Here is a code sniped to demonstrate its power:

In [1]: %load_ext autoreload

In [2]: %autoreload 2

In [3]: from test import Foo

In [4]: foo = Foo()

In [5]: foo.bar()
1

# Edit the code
In [6]: foo.bar()
2

You can put the following into your ipython_config¹ to load and enable the autoreload extension automatically on startup (I only use the first line):

c.InteractiveShellApp.extensions.append("autoreload")
c.InteractiveShellApp.exec_lines = ["%autoreload 2"]

1: Ether

• ~/.ipython/profile_default/ipython_config.py or
• ~/.config/ipython/profile_default/ipython_config.py

en shorterhacks python ipython