I've looked into the source code for some django model fields, in this case DateTimeField. In the tutorial for Django, we are taught to create a DateTimeField like this:
from django.db import models
field = models.DateTimeField()
But looking in the source code, the file where DateTimeField is defined is django/db/models/fields. So, intuitively, if I were to import the field, I would write from django.db.models.fields import DateTimeField. 
Do you see the difference? In the tutorial, they import it from django/db/models, while it looks like from the location of the source code that it actually resides in django/db/models/fields. Why doesn't the tutorial way of importing DateTimeField crash?
 
    