Ah, so in Python, you have "normal code" then you have AST code. Imagine that they were exactly the same, and whenever you're writing "normal code", you're at the same time writing AST code and vice-versa.
So whenever you want, you can start using "normal code" for manipulating the "normal code" itself, and hopefully now we have yet another perspective on the same thing, for why Lisps are so awesome :)
So whenever you want, you can start using "normal code" for manipulating the "normal code" itself, and hopefully now we have yet another perspective on the same thing, for why Lisps are so awesome :)