code:

from sys import argv
from random import shuffle

try:
    with open(argv[1]) as posters:
        posters = list(line.replace('\n', '') for line in posters)
        shuffle(posters)
        pairs = []
        while len(posters) > 1:
            pairs.append("[b]{}[/b] && [b]{}[/b]".format(posters.pop(), posters.pop()))
        if len(posters) == 1:
            print("LONER: {}".format(posters.pop()))
        print(*pairs, sep='\n')
except Exception as e:
    print("Usage: buddydistributor filename.")
    print(e)