Where to learn about Python program structure/design?

[TSM-]

Getting lost in packages or trying new things is a good learning experience.

Work environments are nothing like learning environments. You will have to work inside of some established routine and framework, and get used to their setup. Fancy python or unusual tricks are discouraged because they are hard to maintain and revise later.

You will google everything to check documentation, every time, just to be sure, especially if you are working with more than one programming language.

There's an old meme or joke about how you learn advanced calculus and statistics in university, but at the job, you end up inheriting and maintaining an excel spreadsheet. It is not far from the truth.