python 操作csv

import sys
input_file='E:\test.csv'
output_file='E:\new.csv'
print input_file
with open (input_file,'r') as filereader:
 with open(output_file, 'w') as filewriter:
   header=filereader.readline()
   print header
   print type(header)
   header_list=header.split(',')
   print header_list
   print type(header_list)
   print (','.join(map(str,header_list))+'
')
   for x in filereader:
       row_list=x.split(',')
       filewriter.write(','.join(map(str,row_list))+'
')