For row in read limitation python

Question

I only want to execute this loop rownum times:

rownum = 1000
with open('outputfile.csv', 'wb') as out:
    with open('inputfile.csv', 'rbU') as ifile:
        out_writer = csv.writer(out)
        for row in read:
            out_writer.writerow(row)

Inserting something like for i in range(0, rownum): doesn't work, but I can't make sense of where to put it, either. How do I say for y in x N times ?

Answer 1

Use itertools.islice

for row in itertools.islice(read, stop = rownum):
    out_writer.writerow(row)

Answer 2

if you don't want to import itertools , you can also use enumerate and break :

    for rowidx, row in enumerate(read):
        if rowidx == MAX_ROWS: break
        out_writer.writerow(row)

itertools is more pythonic, though.