>>>Post.objects.all()
[<Post: my post title>, <Post: another post title>]

Post.objects.all()
[]

>>> me = User.objects.get(username='ola')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/home/loma/djanjogirls/myvenv/lib/python3.4/site-packages/django/db/models/manager.py", line 122, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/home/loma/djanjogirls/myvenv/lib/python3.4/site-packages/django/db/models/query.py", line 387, in get
    self.model._meta.object_name
django.contrib.auth.models.DoesNotExist: User matching query does not exist.

p = Post(autor=user, title="заголовок", text="текст")
p.save()

p = Post.objects.create(autor=user, title="заголовок", text="текст")