gistfile1.py

def nameof(obj):
    '''
    if obj is referenced strongly in another object's __dict__, give its attribute name.
    '''

    for r in gc.get_referrers(obj):
        for r2 in gc.get_referrers(r):
            if r is getattr(r2, '__dict__', object()):
                for k, v in r.iteritems():
                    if v is obj:
                        return '[%r attribute of %r]' % (k, r2)