Write list of list to CSV?

[buran]

the easiest way is to make also opo and descname list of lists.
Then use itertools.zip_longest

import itertools
import csv
opo = ['device1', 'device1', 'device1']
intfname = [['HundredGigE0/2/0/0', 'HundredGigE0/2/0/0.242', 'HundredGigE0/2/0/0.244 l2transport', 'HundredGigE0/2/0/1', 'HundredGigE0/2/0/0.244'], ['TenGigabitEthernet1/1/0.138'], ['TenGigE0/1/0/15']]
descname = ['0/2/0/0info1', '0/2/0/0.242info2', '0/2/0/0.244info3']

opo = [[ele] for ele in opo]
descname = [[ele] for ele in descname]
 
## EXPORT AS CSV
with open('intlist.csv', 'w', newline='') as updatecsv:
    write = csv.writer(updatecsv, delimiter=',',lineterminator='\n')
    for cols in zip(opo,intfname,descname):
        rows = itertools.zip_longest(*cols, fillvalue='')
        write.writerows(rows)
updatecsv.close()
print ("Done...")