Filter rows example

filter.py

import io

f = open('somefile.txt','w')
freq = 2

rows = []
rows.append('row a')
rows.append('row b')
rows.append('row c')
rows.append('row d')
rows.append('row e')
rows.append('row f')

def filter_rows(r,f):
    return [row for (i,row) in enumerate(r) if i%f == 0]

f.writelines(["%s\n" % r  for r in filter_rows(rows,freq)])
f.flush()

Cleaner version of my chicken scratch...