You don't need a framework for a single page. That being said, using a framework is probably a good idea if you intend to be on a growth curve.

Pyramid is a framework written to scale from a small, single-file site to a site that has grown horizontally scaled across multiple servers. If I understand your needs correctly, Pyramid is probably worth a look, here's a link: https://trypyramid.com/

Pyramid is under active development, and it has a large, helpful, welcoming user community.