python - How to break a large CSV data file into individual data files? -

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i have csv file first row of contains variables names , rest of rows contains data. what's way break files each containing 1 variable in python? solution going robust? e.g. if input file 100g in size? trying perform divide conquer strategy new python. in advance help!

the input files looks like

var1,var2,var3 1,2,hello 2,5,yay ...

i want create 3 (or many variables) files var1.csv, var2.csv, var3.csv files resemble file1

var1 1 2 ...

file2

var2 2 5 ...

file3

var3 hello yay

as lomg number of columns isn't absurdly huge (larger number of files can have open @ once on platform), number of rows, , total size, no big deal (as long of course have ample free space on disk;-) since you'll processing column @ time -- suggest following code:

import csv  def splitit(inputfilename):   open(inputfilename, 'rb') inf:     inrd = csv.reader(inf)     names = next(inrd)     outfiles = [open(n+'.csv', 'wb') n in names]     ouwr = [csv.writer(w) w in outfiles]     w, n in zip(ouwr, names):       w.writerow([n])     row in inrd:       w, r in zip(ouwr, row):         ouwr.writerow([r])     o in outfiles: o.close()

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