Cut .csv to pieces and save as .csv

[merlem]

Just get the index of the first column and a slice for the second from the list generated for each .csv row.

If I understood correctly, he wish to have _one_ file for the _respective_ colum, that is: not a slice, but just this one column, and the next colum in another file?

And if the data amount is not too big, maybe one could do the datasplitting on a list generated from the source file and do the writing later as 'in one go' for each file?

Edit:
Something like this? I'm not sure how efficient it is for big data amounts, but for a small set, it seems to do what it should (except that it makes a needless file with the dates two times).

import csv
 
f = open("testcsv.csv")
csv_f = csv.reader(f, delimiter=',')

firstlinedone = False
listoffiles = []
for line in csv_f:

    # for the first line, make all files
    if firstlinedone == False:
        for columnumber, column in enumerate(line):
            newfilename = "test" + str(columnumber) + ".csv"
            # one can also do more formatting here for the filename
            newfile = open(newfilename, 'wb')
            listoffiles.append(newfile)
            firstlinedone == True
    for columnumber, column in enumerate(line):
        csvwriter = csv.writer(listoffiles[columnumber], delimiter = ',')
        csvwriter.writerow([line[0], line[columnumber]])

for anyfile in listoffiles:
    anyfile.close()
f.close()