old_contents: """
  Authentication is implemented using flask_login and different environments can
  implement their own login mechanisms by providing an `airflow_login` module
  in their PYTHONPATH. airflow_login should be based off the
  `airflow.www.login`
  """
  from builtins import object
  __version__ = "1.5.2"
  
  import logging
  import os
  import sys
  
  from airflow.configuration import conf, AirflowConfigException
  from airflow.models import DAG
  from flask.ext.admin import BaseView
  from importlib import import_module
  from utils import AirflowException
  
  DAGS_FOLDER = os.path.expanduser(conf.get('core', 'DAGS_FOLDER'))
  if DAGS_FOLDER not in sys.path:
      sys.path.append(DAGS_FOLDER)
  
  auth_backend = 'airflow.default_login'
  try:
      auth_backend = conf.get('webserver', 'auth_backend')
  except AirflowConfigException:
      if conf.getboolean('webserver', 'AUTHENTICATE'):
          logging.warning("auth_backend not found in webserver config reverting to *deprecated*"
                          " behavior of importing airflow_login")
          auth_backend = "airflow_login"
  
  try:
      login = import_module(auth_backend)
  except ImportError:
      logging.critical(
          "Cannot import authentication module %s. "
          "Please correct your authentication backend or disable authentication",
          auth_backend
      )
      if conf.getboolean('webserver', 'AUTHENTICATE'):
          raise AirflowException("Failed to import authentication backend")
  
  
  class AirflowViewPlugin(BaseView):
      pass
  
  
  class AirflowMacroPlugin(object):
      def __init__(self, namespace):
          self.namespace = namespace
  
  from airflow import operators
  from airflow import hooks
  from airflow import executors
  from airflow import macros
  from airflow import contrib
  
  operators.integrate_plugins()
  hooks.integrate_plugins()
  macros.integrate_plugins()
  
new_contents: """
  Authentication is implemented using flask_login and different environments can
  implement their own login mechanisms by providing an `airflow_login` module
  in their PYTHONPATH. airflow_login should be based off the
  `airflow.www.login`
  """
  from builtins import object
  __version__ = "1.5.2"
  
  import logging
  import os
  import sys
  
  from airflow.configuration import conf, AirflowConfigException
  from airflow.models import DAG
  from flask.ext.admin import BaseView
  from importlib import import_module
  from airflow.utils import AirflowException
  
  DAGS_FOLDER = os.path.expanduser(conf.get('core', 'DAGS_FOLDER'))
  if DAGS_FOLDER not in sys.path:
      sys.path.append(DAGS_FOLDER)
  
  auth_backend = 'airflow.default_login'
  try:
      auth_backend = conf.get('webserver', 'auth_backend')
  except AirflowConfigException:
      if conf.getboolean('webserver', 'AUTHENTICATE'):
          logging.warning("auth_backend not found in webserver config reverting to *deprecated*"
                          " behavior of importing airflow_login")
          auth_backend = "airflow_login"
  
  try:
      login = import_module(auth_backend)
  except ImportError:
      logging.critical(
          "Cannot import authentication module %s. "
          "Please correct your authentication backend or disable authentication",
          auth_backend
      )
      if conf.getboolean('webserver', 'AUTHENTICATE'):
          raise AirflowException("Failed to import authentication backend")
  
  
  class AirflowViewPlugin(BaseView):
      pass
  
  
  class AirflowMacroPlugin(object):
      def __init__(self, namespace):
          self.namespace = namespace
  
  from airflow import operators
  from airflow import hooks
  from airflow import executors
  from airflow import macros
  from airflow import contrib
  
  operators.integrate_plugins()
  hooks.integrate_plugins()
  macros.integrate_plugins()
  
subject: Make python 3 compatible