Interactive Python: cannot get `%lprun` to work, although line_profiler is imported properly

To make %lprun work, you need to load the extension into your session, using this command:

In [1]: %load_ext line_profiler

Check out this notebook to see some examples that use the magic.

Besides, if you are working with Spyder, there is also a third-party line_profiler plugin, which you can find here.