> Unless memory mapped by the OS with no impact on runtime for unused parts?

Yeah, this is presumably why a no-op `uv` invocation on my system takes ~50 ms the first time and ~10 ms each other time.

> Exactly, so again have no impact?

Only if your invocation of pip manages to avoid an Internet request. Note: pip will make an Internet request if you try to install a package by symbolic name even if it already has the version it wants in cache, because its cache is an HTTP cache rather than a proper download cache.

But even then, there will be hundreds of imports mainly related to Rich and its dependencies.