https://www.facebook.com/dboyliao/posts/3476230679085922

palindrome.py

import sys


def main():
    n = int(sys.argv[1])
    to_ignore = set([])
    nums = [j for j in range(n, 0, -1)]
    nums += [j for j in range(2, n + 1)]
    for i in range(1, n + 1):
        to_print = [str(j) if j not in to_ignore else " " for j in nums]
        print(" ".join(to_print))
        to_ignore.add(i)


if __name__ == "__main__":
    main()