To be fair, idiomatic python code almost never has the constraints that would make a lens useful. Python programmers would just mutate their datastructures, or

To be fair, idiomatic python code almost never has the constraints that would make a lens useful. Python programmers would just mutate their datastructures, or if they are trying not to mutate the original, copy it and then mutate it, or use a closure to represent the access to the nested structure, something that is about as succinct as representing it via lenses in functional languages. That's why it seems kinda unnecessary as a construct to someone who's only used to thinking about coding that way.