Increase the level of "Type Hinting"

[josecelano]

It seems the developers who are working right not on this project (@yeraydavidrodriguez , @da2ce7 , @josecelano ) are missing a higher level of type hinting on the project. One one the options we were discussing today was to enforce 100% type hinting with mypy.

Python is also making it easier with PEP 484.

We also proposed Rust as an alternative.

Some of the reasons for choosing Python in our initial research were:

Pros:

• There are a lot of packages for image manipulation.
• It's almost the de facto standard language for ML. And We are probably likely to use it in the middle term.
• It has a lot of packages for system operations.
• It's a widely used language so there should be more potential contributors out there.
• We are using DVC and it's written in Python. We thought that the integration with that package in the future could be via API.

Cons:

• We all like Type Hinting. We think it improves readability, robustness and leads you to a better code and more specific error messages (the message and the localization of the error). We could use mypy. But it seems it's not as mature as typescript (IDE support, easy to setup for all python files, ...)
• We do not like how Python handles packages. It's a little bit confusing mixing old-style packages with namespaces packages.