Python widget/cursor detection?

Beginner python learner here. I have a question that I have tried to Google but I just can't come up with the proper way to ask in just a few words (partly because I don't know the right terminology.)

How do I get python to detect other widgets? For example, if I wanted a script to check and see when I click my mouse if that click put focus on an entry widget on a (for example) website. I've been trying to get it to work in Tkinter and I can't figure out even where to begin.

I've seen this:

    focus_displayof(self)
    Return the widget which has currently the focus on the
    display where this widget is located.

But the return value for that function seems to be some ambiguous long number I can't decipher, plus it only works in its own application.

Any direction would be much appreciated. :)

Do you mean inside your own GUI code, or some other application's/website's? Sounds like you're looking for a GUI driver, or GUI test/automation driver. There are tons of these, some great, some awful, many abandoned. If you tell us more about what you want that will help narrow down the choices. Is this for testing, or automation, or are you going to drive the mouse and button yourself and just want something to observe what is going on under the hood in the GUI?

>How do I get Python to detect other widgets?

On a machine, or in a browser? If in a machine, which platform: Linux/Windows (which)/Mac? If in a browser, which browser (and major version)?

> But the return value for that function seems to be some ambiguous long number I can't decipher

Using longs as resource handles is par for the course, although good GUI drivers also work with string/regex matching on window and button names.

> plus it only works in its own application.

What do you mean, and what are you expecting it to return you? You should be able to look up that GUI object and access its title. Look for a GUI driver that works with window and button names.

Here is one list, read it through and see what sounds useful. I have used AutoIt under Win32, it's great, widely-used and actively-maintained; it can be called from Python (via subprocess). Here are comparisons by the author of PyWinAuto on his and similar tools. Give a read to his criticisms of its structure from 2010. If none of these is what you want, at least you now have the vocabulary to tell us what would be...