In server code: error processing request: global name ‘sensor_msgs’ is not defined

edit

For the following code, I am getting the following error:

ERROR: service [/collision_checker] responded with an error: error processing request: global name ‘sensor_msgs’ is not defined

It is a server code and when I run the server, I don’t get error but when I call the server,with no arguments(there is no request argument for that service message type): rosservice call /collision_checker “{}”, I get the error. Any help,advice would be appreciated. I haven’t indented properly here, but I did indent it in my real code.

#!/usr/bin/env python
import rospy
from geometry_msgs.msg import Twist
from std_srvs.srv import Trigger,TriggerResponse,TriggerRequest
from sensor_msgs.msg import LaserScan
class check_collision():
   def __init__(self):
       self.direction=''
       self.collide=False
       self.sub=rospy.Subscriber('/kobuki/laser/scan',sensor_msgs/LaserScan,callback)
   def callback(self,data):
      Response=TriggerResponse()
      if data.ranges[0]<0.3:
         rospy.WARN("You will collide on rightside")
         self.direction="RIGHT"
         self.collide=True
      elif data.ranges[719]<0.3:
         rospy.WARN("Turn right,quick")
         self.direction="LEFT"
         self.collide=True
      elif data.ranges[360]<0.3:
         rospy.WARN("Danger ahead")
         self.direction="AHEAD"
         self.collide=True
      Response.success=self.collide
      Response.message=self.direction
      return Response
  if __name__=="__main__":
      rospy.init_node('check_collision')
      rospy.loginfo("here!")
     def my_fun(Request):
          my_object=check_collision()
     my_service=rospy.Service('collision_checker',Trigger,my_fun)
     rospy.spin()

Edit: Thanks, it worked. Based on your suggestion I tried to change my code, now I am getting another error, could you please look into it.

I have a code which has a server and subscriber. When I run the code using rosrun, I get the following error:

NameError: global name 'my_object' is not defined

Kindly ignore the indentation here, it is correct in my original code.

I would be grateful for any help or advice

#!/usr/bin/env python
import rospy
from geometry_msgs.msg import Twist
from std_srvs.srv import Trigger,TriggerResponse,TriggerRequest
from sensor_msgs.msg import LaserScan
class check_collision():
    def __init__(self,data):
         self.direction=''
         self.collide=False
    def callback(self,TriggerRequest):
         Response=TriggerResponse()
         if self.data.ranges[0]<0.3:
               rospy.WARN("You will collide on rightside")
               self.direction="RIGHT"
               self.collide=True
         elif self.data.ranges[719]<0.3:
               rospy.WARN("Turn right,quick")
               self.direction="LEFT"
               self.collide=True
         elif self.data.ranges[360]<0.3:
               rospy.WARN("Danger ahead")
               self.direction="AHEAD"
               self.collide=True
         Response.success=self.collide
         Response.message=self.direction
         return Response
if __name__=="__main__":
    rospy.init_node('check_collision')
    rospy.loginfo("here!")
    def my_fun(data):
        global my_object
        rospy.loginfo("my_fun called")
        my_object=check_collision(data)
    sub=rospy.Subscriber('/kobuki/laser/scan',LaserScan,my_fun)
    rospy.loginfo("subscriber created")
    my_service=rospy.Service('collision_checker',Trigger, my_object.callback())
    rospy.spin()