CSV: Append firt column with path and filename

import csv

PATH='/home/udacity_driving_datasets'

f1 = open('/home/quest/train.csv')
csv_f = csv.reader(f1)





for row in csv_f:
  name=row[0]
  listt=''
  listt='/home/udacity_driving_datasets/'+name
  with open('/home/trainsample.csv', mode='a') as csv_file:
    fieldnames = ['frame', 'xmin', 'xmax','ymin', 'ymax', 'class_id']
    writer = csv.DictWriter(csv_file, fieldnames=fieldnames)

    # writer.writeheader()
    writer.writerow({'frame': listt, 'xmin': row[1], 'xmax': row[2], 'ymin': row[3], 'ymax': row[4], 'class_id':row[5]})
    print("copies row")