old_contents: # -*- coding: utf-8 -*-
  
  from django.contrib.gis.db import models
  
  try:
      from django.utils.encoding import force_unicode as force_text
  except (NameError, ImportError):
      from django.utils.encoding import force_text
  from django.utils.encoding import python_2_unicode_compatible
  from django.core.validators import MinLengthValidator
  from django.utils.translation import gettext_lazy as _
  
  from .conf import DJANGO_VERSION
  
  if DJANGO_VERSION < 2:
      from django.contrib.gis.db.models import GeoManager
  else:
      from django.db.models import Manager as GeoManager
  
  
  @python_2_unicode_compatible
  class Airport(models.Model):
      name = models.CharField(_("name"), max_length=100)
      city_name = models.CharField(_("name"), null=True, blank=True, max_length=100)
  
      iata = models.CharField(_("IATA/FAA code"), null=True, blank=True, max_length=3,
                              validators=[MinLengthValidator(3)])
      icao = models.CharField(_("ICAO code"), null=True, blank=True, max_length=4,
                              validators=[MinLengthValidator(4)])
      local = models.CharField(_("Local code"), null=True, blank=True, max_length=12)
      ident = models.CharField(_("Ident code"), null=True, blank=True, max_length=12)
  
      altitude = models.FloatField(_("altitude"), default=0)
      location = models.PointField(_("location"))
  
      country = models.ForeignKey('cities.Country', on_delete=models.DO_NOTHING, null=True)
      region = models.ForeignKey('cities.Region', on_delete=models.DO_NOTHING, null=True)
      city = models.ForeignKey('cities.City', on_delete=models.DO_NOTHING, null=True)
      type = models.CharField(max_length=16, default='')
  
      objects = GeoManager()
  
      class Meta:  # pylint: disable=C1001
          ordering = ['id']
  
      def __str__(self):
          return force_text(self.name)
  
new_contents: # -*- coding: utf-8 -*-
  
  from django.contrib.gis.db import models
  
  try:
      from django.utils.encoding import force_unicode as force_text
  except (NameError, ImportError):
      from django.utils.encoding import force_text
  try:
      from django.utils.encoding import python_2_unicode_compatible
  except (NameError, ImportError):
      from six import python_2_unicode_compatible
  from django.core.validators import MinLengthValidator
  from django.utils.translation import gettext_lazy as _
  
  from .conf import DJANGO_VERSION
  
  if DJANGO_VERSION < 2:
      from django.contrib.gis.db.models import GeoManager
  else:
      from django.db.models import Manager as GeoManager
  
  
  @python_2_unicode_compatible
  class Airport(models.Model):
      name = models.CharField(_("name"), max_length=100)
      city_name = models.CharField(_("name"), null=True, blank=True, max_length=100)
  
      iata = models.CharField(_("IATA/FAA code"), null=True, blank=True, max_length=3,
                              validators=[MinLengthValidator(3)])
      icao = models.CharField(_("ICAO code"), null=True, blank=True, max_length=4,
                              validators=[MinLengthValidator(4)])
      local = models.CharField(_("Local code"), null=True, blank=True, max_length=12)
      ident = models.CharField(_("Ident code"), null=True, blank=True, max_length=12)
  
      altitude = models.FloatField(_("altitude"), default=0)
      location = models.PointField(_("location"))
  
      country = models.ForeignKey('cities.Country', on_delete=models.DO_NOTHING, null=True)
      region = models.ForeignKey('cities.Region', on_delete=models.DO_NOTHING, null=True)
      city = models.ForeignKey('cities.City', on_delete=models.DO_NOTHING, null=True)
      type = models.CharField(max_length=16, default='')
  
      objects = GeoManager()
  
      class Meta:  # pylint: disable=C1001
          ordering = ['id']
  
      def __str__(self):
          return force_text(self.name)
  
subject: Fix import error