text: #
  # Licensed to the Apache Software Foundation (ASF) under one
  # or more contributor license agreements.  See the NOTICE file
  # distributed with this work for additional information
  # regarding copyright ownership.  The ASF licenses this file
  # to you under the Apache License, Version 2.0 (the
  # "License"); you may not use this file except in compliance
  # with the License.  You may obtain a copy of the License at
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing,
  # software distributed under the License is distributed on an
  # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, either express or implied.  See the License for the
  # specific language governing permissions and limitations
  # under the License.
  """This module contains SFTP sensor."""
  from typing import Optional
  
  from paramiko import SFTP_NO_SUCH_FILE
  
  from airflow.providers.sftp.hooks.sftp import SFTPHook
  from airflow.sensors.base import BaseSensorOperator
  from airflow.utils.decorators import apply_defaults
  
  
  class SFTPSensor(BaseSensorOperator):
      """
      Waits for a file or directory to be present on SFTP.
  
      :param path: Remote file or directory path
      :type path: str
      :param sftp_conn_id: The connection to run the sensor against
      :type sftp_conn_id: str
      """
  
      template_fields = ('path',)
  
      @apply_defaults
      def __init__(self, *, path: str, sftp_conn_id: str = 'sftp_default', **kwargs) -> None:
          super().__init__(**kwargs)
          self.path = path
          self.hook: Optional[SFTPHook] = None
          self.sftp_conn_id = sftp_conn_id
  
      def poke(self, context: dict) -> bool:
          self.hook = SFTPHook(self.sftp_conn_id)
          self.log.info('Poking for %s', self.path)
          try:
              mod_time = self.hook.get_mod_time(self.path)
              self.log.info('Found File %s last modified: %s', str(self.path), str(mod_time))
          except OSError as e:
              if e.errno != SFTP_NO_SUCH_FILE:
                  raise e
              return False
          self.hook.close_conn()
          return True
  