Disclaimer: I've just started researching this area/domain of knowledge; so I have no idea what exactly it's called; but through a google search, I believe it has to do with (static code analysis, or at least it's related to it).

My question is: Given a python code - file - script - module - package. Is there a tool that can produce a report out of it detailing: how many classes are used, functions, built-in functions; decorators ;if/for/while statements etc?

To give you an analogy most of us can relate to: Given a text file: find all the verbs / nouns / adjectives / adverbs / proper noun. NLP tools like spaCy or NLTK have the ability to do that for natural languages.

But what about programming languages? Is there a tool for that? Can a tool like pylint do that?

UPDATE

As I expected such tools exist; one of them as @BoarGules suggested in his comment is the ast module ... It's the hint I needed to go further in my research; any further suggestions are welcome. BTW ast stands for abstract syntax tree.

Given a python code - file - script - module - package. Is there a tool that can produce a report out of it detailing: how many classes are used...

There cannot be an exact tool for that, since Python has an eval primitive.

When that primitive is executed, the set of classes or functions of your Python program can increase.

Be aware of Rice's theorem.

Consider using abstract interpretation and type inference techniques in your Python static analyzer.

Consider also using (painfully) Frama-C on the source code (the code written in C) of the Python interpreter. With a lot of work, Frama-C could be extended to analyze Python source code.

Read also recent proceedings of ACM SIGPLAN conferences.