```
As we can see, we have loaded the module from site_packages as expected - and our build and installation is successful!
Note: Python prepends the empty string to sys.path to represent the current working directory - making it the first place we search for a module. So if we run Python from the pytorch directory, we would accidentally load the local version of PyTorch rather than our installed version. This is something to watch out for.
Addendum - Developer Efficiency, 3rd Party Libraries, Things I Didn't Cover
The entire installation loop for PyTorch can be quite time-consuming. On my devserver, it takes around 5 minutes for an installation from source. Often times, when developing PyTorch, we only want to work on a subset of the entire project, and re-build only that subset in order to test changes. Fortunately, our build system enables this.
Setuptools Develop Mode
The main tool that supports this is Setuptools develop command. The documentation states that: