I have written a python package which consists of several `.py` files which contain classes and so on. I want to expose it to client using "Facade" pattern. So I don't want clients to learn all internal classes but only methods exposed by this API interface.

Question is: where do I put this api ? Do I define a file `api.py` inside the package or can I put this api in the `__init__.py` of the package?

I explain better with an example

```
<my_module>\
     __init__.py
     core.py
     submodule1.py
     submodule2.py
     util.py
     ........

```

so where do I put the public API of ?