In module A, I import module B. Then, in module C, I import module A. In module C, will I be able to use the content of module B implicitly via the import of module A, or will I have to explicitly import it into module C?

That should work just fine. However, it would save you some trouble to explicitly import the module as well if only to keep track in your head when looking back at code

If you have any other questions about importing, try taking a gander to this article here

https://docs.python.org/3/reference/import.html

It should help.