How to organize the module imports from a Python library?

Question

I'm developing a Python library but I'm having some troubles organizing its structure and overall its imports on the init.py files.

Currently, my project has this structure:

module/
├─ submodule/
│  ├─ __init__.py
│  └─ class2.py
├─ __init__.py
├─ class1.py
└─ setup.py

main.py

So, the logic within it is that the class inside class2.py (called Class2) inherits from the class inside class1.py (called Class1, which contains almost only the skeleton for different types of implementations like the one in class2.py) and in the main.py (which is outside the module folder) I'm trying to create an object of the class from class2.py to test the module.

The problem is that I'm receiving this error when I execute the main:

ImportError: cannot import name 'Class1' from partially initialized module 'module' (most likely due to a circular import)

I think that I'm messing up with the imports on the __init__.py files, because I would like to prettify the calling of the classes. I'll explain:

1. I want to be able to call module.Class1 directly and not just module.class1.Class1, so I've added a from module.class1 import Class1 in the main module __init__.py.
2. I want to be able to call elements from the submodule just importing the main module, like module.submodule.Class2, so I've added an from module import submodule to the main module __init__.py and a from module.submodule.class2 import Class2 to the submodule __init__.py.

And I firmly think that's what is messing things up, so it would be amazing if someone could explain me how this kind of structure should be done and how the imports have to be organized in order to have a clear visibility of the desired elements directly when calling the main module (e.g. when I write module. in the editor and ask it for suggestions to autocomplete I would like to see the suggestions like I've listed above)