It follows then that the 'base' language [or interpreter in the classical sense] that you use to do that, should not get in your way and must be primarily focused in facilitating that process.

Python is not that language since it's very opinionated and constrained by its decisions in the design space and, additionally, has been _deliberately_ created with entirely different considerations in mind. This is very well illustrated by the idiotic Python moto "There's only one way to do it" which, in practice, isn't even the case for Python itself. A perfect example of style over substance, yet people lap it up.

You can pick and choose a few features that seem similar to Lisp features [even though they are not] but that does not make Python a good language for metalinguistic abstraction. This is a classic example of the whole of Lisp being much more than the sum of its parts, and in reality languages like Python don't even do a good job of reimplementing some of these parts. Going back to what I wrote in the beginning, what fundamentally new ideas and notions about computation that have stood the test of time did you see arising from Python?

If you look at Norvig's Lisp-Python article and the grammar example, the code with the ad hoc language is still smaller and easier read than than the Lisp example.