models.User.objects.create(c1='a',c2='b')

     obj=models.User(c1='a',c2='b')

     obj.save()

     models.User.objects.get(id=1)

     models.User.objects.all()

     models.User.objects.filter(id=2)

     models.User.objects.exclude(name='anna')

 models.User.objects.filter(username='anna').remove()

     models.User.objects.filter(username='anna').update(gender=0)

     obj=models.User.objects.get(id=1)

     obj.gender=''

     obj.save()