old_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  import os
  from i3pystatus.mail import Backend
  
  
  class MaildirMail(Backend):
      """
      Checks for local mail in Maildir
      """
  
      settings = (
          "directory",
      )
      required = ("directory",)
  
      directory = ""
  
      @property
      def unread(self):
          path = os.path.join(self.directory, "new")
          return len([name for name in os.listdir(path)])
  
  
  Backend = MaildirMail
  
new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  import os
  from i3pystatus.mail import Backend
  
  
  class MaildirMail(Backend):
      """
      Checks for local mail in Maildir
      """
  
      settings = (
          "directory",
      )
      required = ("directory",)
  
      directory = ""
  
      @property
      def unread(self):
          path = os.path.join(self.directory, "new")
          return len(os.listdir(path))
  
  
  Backend = MaildirMail
  
subject: remove useless list comprehension