
The Python interpreter looks into `site_packages` during an import. If we call `import torch` in our Python code it will find the module here and initialize and import it. You can read more about the import system [here](https://docs.python.org/3/tutorial/modules.html).

### Building Individual Parts

Next, we will look at the various individual components of the build from start to finish. This will illustrate how we combine all the code we mentioned in the introduction.

### Backend Torch and Vendor Libraries

Let's take a look at the `install` cmd override in PyTorch's `setup.py`:

```python
class install(setuptools.command.install.install):

    def run(self):
        if not self.skip_build:
            self.run_command('build_deps')
        setuptools.command.install.install.run(self)

We note the first thing it does is run a command called "build_deps" - let's take a look at it's run() method:
```python
def run(self):
        from tools.nnwrap import generate_wrappers as generate_nn_wrappers