Need Help writing data into Excel format

[ajitnayak87]

I have the below code. I have one counter. if counter less than value set value It should write the value into excel.
in below code I could see counter printing 0 and hangs

The filed column should be written only once
I wanted to write into excel per 1S time sleep
Counter has to increment every time and save into SL no


I have used pyscripter 4

import csv
import datetime
import time
from datetime import datetime

filename = "TestFormat.csv"
fields = ['SLNo', 'Date','Time', 'RData', 'BData','GData','IRdata']


def main():
   count=0
   while(count<10):
        print("Counter:",count)
        now = datetime.now()
        Sln0=count
        date_Format=now.strftime('%Y/%m/%d ')
        current_time = now.strftime("%I:%M:%S")
        with open(filename, 'a+') as csvfile:
            csvwriter = csv.writer(csvfile)
            csvwriter.writerow(fields)
            csvwriter.writerow([Sln0,date_Format,current_time])
        csvfile.close()
   count=count+1

if __name__ == '__main__':
    main()
    time.sleep(1)