Do you mean function definitions? They are executable statements after all. Yes the Python environment is just a bunch of nested dictionaries. Whether there is bytecode is up to the implementation. If you want to understand how CPython works, the source code is not terribly mysterious if you know C. You will want to read the API document first.
For the language itself, the reference manuals are reasonably good.
Do I really have to have written "stop changing the defaults"? Like if Firefox kept changing its keyboard shortcuts would that be non-annoying as long as you can reset them? Oh yes, they DO that.
Would you like to swing on a star? Carry moonbeams home in a jar? And be better off than you are? Or would you rather be a mule?
https://www.youtube.com/watch?v=QyHJ6drXXBY