Python in Linux environment on RPI

[kendias]

Thanks.
No output after removing comments from script in my previous post but do get output from script below. It prints lat, lon but into the python shell i.e. print works but  f.write does not work.

from gps import *
import time
import threading
f = open("locations.csv","w")
gpsd = None
class GpsPoller(threading.Thread):
  def __init__(self):
      threading.Thread.__init__(self)
      global gpsd
      gpsd=gps(mode=WATCH_ENABLE)
      self.current_value = None
      self.running = True
            
  def run(self):
      global gpsd
      while gpsp.running:
          gpsd.next()
          print (gpsd.fix.longitude)
          print (gpsd.fix.latitude)
        
if  __name__ == '__main__':
  
  gpsp=GpsPoller()
  try:
      gpsp.start()
      
      while True:
          f.write(str(gpsd.fix.longitude) + "," + str(gpsd.fix.latitude) + "\n") 
        
          time.sleep(30)
  except(KeyboardInterrupt,SystemExit):
      f.close()
      gpsp.running = False
      gpsp.join()