import datetime

LOG_LEVEL_INFO = 0
LOG_LEVEL_ERROR = 1


def log(log_level, format_string, *args, out_file=None):
    if log_level == LOG_LEVEL_INFO:
        prefix = '[info] '
    else:
        prefix = '[error] '

    now = datetime.datetime.now()
    date = '[%d-%02d-%02d %02d:%02d]' % (
        now.year,
        now.month,
        now.day,
        now.hour,
        now.minute
    )

    output = ''.join((date, prefix, format_string.format(*args)))
    print(output)

    if out_file is not None:
        with open(out_file, 'a') as f:
            f.write(output + '\n')