Streaming and lazy evaluation is definitely a solution here. But do python libraries support it well?

You can't have true lazy evaluation because you still need the maximum and minimum to normalise them. But that's just two fields that you need only once.

I have no idea whether python or any other language supports this out of the box, but I would expect there are libraries that do this, and if not, it shouldn't be too hard to write this yourself. The main thing is probably that you need to separate the normalisation parameters from the normalisation itself, and after that, you can simply do something like (in javascript):

  array.forEach(e => visualise(normalise(e, min, max)));

Of course visualisation is probably going to involve a new datastructure that's going to hold this data in some way, so there's still going to be another copy of that array living somewhere. That's unavoidable.