How much complexity is good/overkill?
Lately I showed one of my beginner works to a friend who is a Java developer. He criticized a few things, one of them being that I don't have different files for functions, front-end and so on. From my perspective, this didn't appear necessary: Since the whole script was below 200 lines, what would be the benefit of several files which would necessitate a folder and so on? Also I recently watched a YouTube video where a developer showed examples of people writing a few dozen lines of class definition, although a simple function of a few lines using built-ins would have done the job just the same. Python is my first programming language, and since I am now trying to figure out the OOP stuff, I'd like to hear your opinions: How much complexity, modularization and objectification (that a word?) is optimal and how can I judge that from case to case?