I want a key press to be mapped with a button click function in Gtk-python, i.e. if Enter key is pressed, the data-process function should execute, which is called by pressing the process button.
Can this be done?
Assuming you are using a gtk.Entry() and a gtk.Button(), I think what you need to do is just connecting the gtk.Entry() to your data-process function like this:

    b = gtk.Button("Process")
    b.connect("clicked", data-process)
    e = gtk.Entry()
    e.connect("activate", data-process)
That should do the "Trick".
Hope this helped.
Map a key press to a button click in Gtk Python