old_contents: from django.db import models
  
  
  class Maintenance(models.Model):
      enabled = models.BooleanField()
      start_time = models.DateTimeField()
      end_time = models.DateTimeField()
      description = models.TextField()
      
      def __unicode__(self):
          return self.start_time.isoformat()
          
  class MaintenanceFilter(models.Model):
      maintenance = models.ForeignKey(Maintenance)
      path = models.CharField(max_length=128)
new_contents: # coding: utf-8
  from django.db import models
  from django.utils.translation import ugettext_lazy as _, pgettext_lazy
  
  
  class Maintenance(models.Model):
      """
      Maintenance scheduling
      """
      enabled = models.BooleanField(default=True, null=False, verbose_name=pgettext_lazy('maintenance', u"Enabled"))
      start_time = models.DateTimeField(blank=False, null=False, verbose_name=_(u"Start time"))
      end_time = models.DateTimeField(blank=False, null=False, verbose_name=_(u"End time"))
      description = models.TextField(verbose_name=_(u"Description"))
      
      def __unicode__(self):
          return self.start_time.isoformat()
          
      class Meta:
          verbose_name = _(u"maintenance schedule")
          verbose_name_plural = _(u"maintenance schedules")
  
  
  class MaintenanceFilter(models.Model):
      """
      Filter maintenance schedule py path
      """
      maintenance = models.ForeignKey('maintenance.Maintenance')
      path = models.CharField(max_length=128, blank=False, verbose_name=pgettext_lazy('url', u"Path"))
  
      class Meta:
          verbose_name = _(u"maintenance filter")
          verbose_name_plural = _(u"maintenance filtering")
  
subject: Update models.py