Python out of range on CSV after os functions -

this question has answer here:

• why csv file contain blank line in between each data line when outputting dictwriter in python [duplicate] 4 answers

i'm trying make program takes questions csv file asks them weighted score. lowest scored ones go first.

to have sort function.

def sort_records(csv_filename, sorted_file):     open(csv_filename, 'r') i, open(sorted_file, 'w') o:         reader = csv.reader(i, delimiter = ',')         writer = csv.writer(o, delimiter=',')         writer.writerow(next(reader)) # header row         writer.writerows(sorted(reader, key=operator.itemgetter(0))) 

this works first time, no problem.

but when there no more questions asked , if user decides run program again, takes files have been written (new_filename called answer_file) , deletes original file , sorted file (file, sorted_file) renames updated file (answer_file) 'file'

def end(file, updated_file, sorted_file):     ans_ok = false     while ans_ok == false:         ans = input("that's folks... go again? y/n: ")         ans.upper()         if ans == 'n':             print("press enter exit...")             input(" ")             ans_ok = true         elif ans == 'y':             os.remove(file)             os.remove(newfile)             os.rename(updated_file,file)             print("\n ok!\n")             main() 

and when try run main function again works , subsequently runs sort_records function updated file had been renamed comes with:

line 24, in sort_records writer.writerows(sorted(reader, key=operator.itemgetter(0))) indexerror: list index out of range 

edit. main function calling both of these

def main():     path_ok = false     while path_ok == false:         try:             file = input("subject file: ")             sorted_file = file[:-4]+'_sorted.sar'             sort_records(file,sorted_file)             path_ok = true         except ioerror:             print("\tfile not found. please input valid filename or path")      updated_file = sorted_file[:-4]+'_final.sar'     rownum = 0     open(newfile) csvfile:         reader = csv.dictreader(csvfile)         row in reader:             rownum+=1             ask_question(row,updated_file,reader,sorted_file,file,rownum)     end(file, updated_file, sorted_file) 

main first function called in program also

update have found comparing 2 files' text outside of notepad, new file generated program looks this: the text in both files

notepad did not show reason.

now have question:

how write csv file in python without automatically putting blank line in-between lines being written?

ok, sorted. turns out case, story on :)

second question answered by: why csv file contain blank line in between each data line when outputting dictwriter in python

thanks stackoverflow!