"Building" the Pure Python Modules
Now that we have built the backend libraries (the "dependencies") we can move forward with building the actual PyTorch code. The next Setuptools command that runs is build_py, which is used to build all the "Pure" python modules in our library. These are the "packages" passed to setup.py.
The packages are found using the Setuptools' utility function find_packages():
```python
packages = find_packages(exclude=('tools.*',))