Write Lists Of Different Size To Csv In Columns In Python

I need to write lists that all differ in length to a CSV file in columns. I currently have: d=lists writer = csv.writer(fl) for values in zip(*d): writer.writerow(values) whic

Solution 1:

Code below is for Python 3. If you use Python 2, import izip_longest instead of zip_longest.

import csv
from itertools import zip_longest

d = [[2,3,4,8],[5,6]]

with open("file.csv","w+") as f:
    writer = csv.writer(f)
    for values in zip_longest(*d):
        writer.writerow(values)

Result:

2,5
3,6
4,
8,

Solution 2:

There's no 'neat' way to write it since, as you said, zip truncates to the length of the shortest iterable.

Probably the simplest way would be to just pad with None or empty strings (Not sure offhand what the behavior of writerow is with None values):

maxlen =max([len(member) formemberin d])
[member.extend([""] * (maxlen - len(member))) formemberin d]
forvaluesin zip(*d):
    ...

Alternatively, you could just construct each row inside the for loop instead of using zip, which would be more efficient but a lot wordier.

EDIT: corrected example