How to get every 3rd lines from a csv file using python?
import csv
with open ('data.csv','r') as infile:
contents = csv.reader(infile, delimiter =' ')
then???
The csv file looks like:
aaaaaaaaaaaaaaaa
bbbbbbbbbbbbbbbb
only recquired line
cccccccccccccccccccccccccc
ddddddddddddddddddddddddd
only recquired line
The result should look like:
only recquired line
only recquired line
To avoid loading the entire file into memory, you could use itertools.islice
from itertools import islice
with open ('data.csv','r') as infile:
x = islice(infile, 2, None, 3)
for line in x:
print line
for index, line in enumerate(fileOfInterest, 1):
if index % 3 == 0:
doSomething
Alternatively, you can use python's extended slice notation as in:
for line in fileOfInterest[2::3]
doSomething
However, 1_CR's answer is the one I would go with!
with open('test.csv') as hf:
print [line for line in list(hf)[2::3]]
Using the extended slice notation:
for i in contents.splitlines(True)[2::3]:
print (i)
contents.splitlines(True)[2::3]