Get instance of an running Python program
You can't (easily) "get an instance of a running program" from outside. You can certainly instrument your program so that it communicates its statistics somehow, eg via a socket, or as an even lower-tech solution you could get it to store the relevant data periodically in a file on disk or in a database, which your web app could read.
Suppose a python program is running. Say the object of an Class in that program can give you some stats. So if i have to develop a web UI to display the stats, how do i get the instance of that class which is running[as an separate desktop app] and display the stats in web, which I would be using web2py or django.