Need help in rospy programming

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hi,

I wish to program my robot such that whenever the Lidar detect an obstacle, a 'stop' will be printed every 1 second. However, whenever I place remove the obstacle, the output will not stop printing 'stop'.

Can someone kindly help me in this programming?

Below is my code:

#!/usr/bin/env python
from __future__ import print_function
import sys
import rospy
from sensor_msgs.msg import ,LaserScan
import os


def stop():
            print('stop')
            time.sleep(1)

class obstacle_detector:

  def __init__(self):
    self.laser_scan_sub = rospy.Subscriber("/scan_raw",LaserScan,self.lasercallback)

  def lasercallback(self,data):
        angle = 285
        self.laser_scan = 10000000
        for x in range (90):
         if data.ranges[angle] <  self.laser_scan:
             self.laser_scan = data.ranges[angle]
         angle = angle + 1
         if self.laser_scan < 1.5:
              stop()
         else:
              print('go')

def main(args):
  ic = obstacle_detector()
  rospy.init_node('obstacle_detector', anonymous=True)
  try:
    rospy.spin()