'Generate and return data for `num` attachments'

def _attachments(self, num):

    data = {}
    files = ['bacon.jpg', 'bacon.txt']
    descriptions = ['mmm,    bacon', '']
    for n in xrange(num):
        i = (0 if (n % 2) else 1)
        path = os.path.join(ATTACHMENTS_DIR, files[i])
        attachment = open(path, 'r')
        data.update({('form-%d-attachment' % n): attachment, ('form-%d-description' % n): descriptions[i]})
    return data
