reading message once subscribed to a topic

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Hi i am new to ROS, i have done the tutorials. But i am a bit unsure on how to read messages (in code)

If i have a ros node which has subscribed to a topic /LaserScan see bellow std_msgs/Header header float32 angle_min float32 angle_max float32 angle_increment float32 time_increment float32 scan_time float32 range_min float32 range_max float32[] ranges float32[] intensities

And I am in my call back function, def callback_lidar(data):

how do i access an individual variables, like the list ranges

would i do array = data.ranges?

I cant create the node an test it out since the lidar node requires a connected lidar.