Adding Signals

import gobject, gtk

class MyWidget(gtk.Widget):
    __gsignals__ = {
        'mysignal': (gobject.SIGNAL_RUN_FIRST,
                     None, (int,))
    }

    ...

    def do_mysignal(self, intarg):
        print 'Integer argument:', intarg

gobject.type_register(MyWidget)

w = MyWidget()
w.connect('mysignal', function)
w.emit('mysignal', 42)