old_contents: from django.db import models
  from django.contrib.auth.models import User
  
  
  class DatasetLicence(models.Model):
      title = models.CharField(max_length=255)
      short_title = models.CharField(max_length=30)
      url = models.URLField()
      summary = models.TextField()
      updated = models.DatetimeField(auto_now=True)
      created = models.DatetimeField(auto_now_add=True)
  
  
  class FileFormat(models.Model):
      extension = models.CharField(max_length=10)
      description = models.TextField()
      updated = models.DatetimeField(auto_now=True)
      created = models.DatetimeField(auto_now_add=True)
  
  
  class Dataset(models.Model):
      title = models.CharField(max_length=255)
      licence = models.ForeignKey('DatasetLicence')
      file = models.FileField()
      file_format = models.ForeignKey('FileFormat')
      description = models.TextField()
      author = models.ForeignKey(User)
      updated = models.DatetimeField(auto_now=True)
      created = models.DatetimeField(auto_now_add=True)
  
new_contents: from django.db import models
  from django.contrib.auth.models import User
  
  
  class DatasetLicence(models.Model):
      title = models.CharField(max_length=255)
      short_title = models.CharField(max_length=30)
      url = models.URLField()
      summary = models.TextField()
      updated = models.DateTimeField(auto_now=True)
      created = models.DateTimeField(auto_now_add=True)
  
  
  class FileFormat(models.Model):
      extension = models.CharField(max_length=10)
      description = models.TextField()
      updated = models.DateTimeField(auto_now=True)
      created = models.DateTimeField(auto_now_add=True)
  
  
  def get_dataset_upload_path(self, instance, filename):
      return '/%s/' % instance.author.username
  
  class Dataset(models.Model):
      title = models.CharField(max_length=255)
      licence = models.ForeignKey('DatasetLicence')
      file = models.FileField(upload_to=get_dataset_upload_path)
      file_format = models.ForeignKey('FileFormat')
      description = models.TextField()
      author = models.ForeignKey(User)
      updated = models.DateTimeField(auto_now=True)
      created = models.DateTimeField(auto_now_add=True)
  
subject: Add dataset upload_to attribute. Fix DateTimeField name.