I am porting some matlab code to python. I need to work with packages and modules in this case. The relevant package directory structure looks like this:

```
toppackage
    __init__.py
    subpackage
        __init__.py
        module.py
        ...

```

In the script I use the package, I can work like this:

```
from toppackage.subpackage.module import SomeClass
s = SomeClass()

```

But I would prefer working like this:

```
import toppackage %somewhere at the beginning of file
s = toppackage.subpackage.module.SomeClass()

```

I see this is done in numpy. But I could not find it in documentation. How can I do that?

Thanks in advance.