One of the main purposes of connect_object is the signal should disconnect automatically based on the lifetime of the object argument. This is not working correctly in python likely due to the method holding a strong reference to the object argument. This is observed as follows:

import weakref, gc
from gi.repository.GObject import Object, Property

class O(Object):
    foo = Property(type=int)
    def callback(self, *args):
        print(args)

o1 = O()
o2 = O()
w1 = weakref.ref(o1)
w2 = weakref.ref(o2)

o1.connect_object('notify', O.callback, o2)
o1.notify('foo')  # callback prints
del o2
gc.collect()

o1.notify('foo')  # callback still prints
w2()  # <O object...>  (should be None)

del o1
gc.collect()
w1()  # None
w2()  # None (after the reference held by the w1 connection is released).



The fix should probably be to use a weak reference to the python object (o2) passed in if possible.