parsing - python: how to delete row and modify specific list string from CSV -

this first time posting question apologise in advance if make mistakes.

i attempting create custom python program (pretty parser) takes in data such:

junk junk junk junk junk junk fields       title   title   title data_type   d_type  d_type  d_type data1   data2    data 3 data4   data 5   data6 data7   data8    data9 junk 

where desired output is:

title   title   title data1   data2   data3 data4   data5   data6 data7   data8   data9 

here working portion of code have far:

import csv import itertools open('file.log','rb') csvfile:     rowlist = csv.reader(csvfile, delimiter = '\t')     row in itertools.islice(rowlist,6,12):        print row 

whenever above code run produces series of lists seen here

['fields','title1', 'title2', 'title3'] ['data_type','d_type','d_type', 'd_type'] ['data1', 'data2', 'data3'] ['data4', 'data5', 'data6'] ['data7', 'data8', 'data9'] 

the first data entry (data1, data4, data7) in list number whereas other data entries may string/number/character.

the itertools has solved cutting off top , bottom of file, still struggling to

• delete "data_type line"
• removing 'fields', is: ['fields','title1', 'title2', 'title3']----->['title1', 'title2', 'title3']

i have seen solutions remove lines/overwrite line however, not have lot of memory spare must keep opening/closing/writing minimum. , extremely appreciated.

just slice each row:

  row in islice(rowlist, 6, 12):     if row[0] == "data_type":         continue     elif row[0] == "fields":           print(row[1:])     else:         print(row) 

if writing rows use islice again:

for row in islice(rowlist, 6, 12):     if row[0] == "data_type":         continue     elif row[0] == "fields":          fileobj.write(islice(rowlist, 1,none))     else:         fileobj.write(row) 

if trying overwrite original file, can write lines tempfile , replace original file shutil.move:

from shutil import move tempfile import namedtemporaryfile  open('file.csv', 'rb') csvfile, namedtemporaryfile(dir=".", delete=false) temp:     rowlist = csv.reader(csvfile)     row in islice(rowlist, 6, 12):         if row[0] == "data_type":             continue         elif row[0] == "fields":             temp.write(islice(rowlist, 1, none))         else:             temp.write(row)  move(temp.name,"file.csv")