Битовый запрос с F?

In [71]: User.objects.all().count()
Out[71]: 554

In [72]: len(filter(lambda x: x!=0, [im.alert_flags & 0b00010000 for im in User.objects.all()]))
Out[72]: 517

In [73]: len(filter(lambda x: x==0, [im.alert_flags & 0b00010000 for im in User.objects.all()]))
Out[73]: 37

In [74]: User.objects.filter(alert_flags=F('alert_flags').bitand(0b00010000)).count()
Out[74]: 63