Web Interface for Python

An ongoing project I've been wanting propose to a certain very large government agency involves creating a front-end for Python algorithms.  The first question is what should the interface be:

• GUI - Would be great, but would need to be developed for all OS's including Mobile in my vision.  How fancy do I get, do I use Tcl/Tk, or even Qt?  I'm starting to feel overwhelmed already with all the Python GUI frameworks.  
• Web - This would be ideal, as long as it follows standard HTML standards, then one deployment should work for everyone with Internet access.  But how?  Django doesn't seem to be interactive enough for my needs and also seems a bit of an overkill with the ORM.  Flask seems to be too light.  Hmm, and then I got some advice from the author of http://pythonprogramming.net on Reddit.

He pointed me to two amazing projects, and I'm seriously thinking about diving back into this proposal.  He recommended I look into the following projects:

Brython:

"Brython is designed to replace Javascript as the scripting language for the Web. As such, it is a Python 3 implementation (you can take it for a test drive through a web console), adapted to the HTML5 environment, that is to say with an interface to the DOM objects and events"
Trinket:
"Trinket lets you run and write code in any browser, on any device.
Trinkets work instantly, with no need to log in, download plugins, or install software.
Easily share or embed the code with your changes when you're done."


These look to be two amazing projects that I think I could leverage.  Here, check it out.

Trinket: Brython: