test.py

#!/usr/bin/env python
import sys
import csv
import os

if __name__ == '__main__':
    data = [[i if i == j else 0 for i in range(5)] for j in range(5)]
    # => [[0, 0, 0, 0, 0], [0, 1, 0, 0, 0], [0, 0, 2, 0, 0], [0, 0, 0, 3, 0], [0, 0, 0, 0, 4]]
    # dialect = 'excel'
    # csv.writer(sys.stdout).writerows(data)
    csv.writer(sys.stdout, lineterminator = os.linesep).writerows(data)