> Ad infinitum

The result of module import is cached (which is also what makes it valid to use a module as a singleton); you do not pay this price repeatedly. Imports can also be deferred; `import` is an ordinary statement in Python which takes effect at runtime rather than compile time.

Modules that are slow to import are usually slow because of speculatively importing a large tree of sub-modules. Otherwise it's because there's actual work being done in the top-level code, which is generally unavoidable.

(Requests is "only" around a .1s import on my 11-year-old hardware. But yes, that is still pretty big; several times as long as the Python interpreter plus the default modules imported automatically at startup.)