Which framework is better for automating a Desktop Application with python

Honestly, there's not necessarily enough information in what you've described to give you a particular framework to use. Are you testing data entry into forms? Are you testing an application that reads and responds to data input? What exactly are you testing?

Just off the top of my head... I would suggest, if you're doing data entry testing or something similar, construct your namemapping in a POM structure for the different forms but then use a Data-Driven test framework to iterate through your data scenarios to do the testing itself.