你会添加背景吗

# ensure函数如下：
log = print
def apply_compare(nlist):
    if nlist[0] == ">":
        if nlist[1] > nlist[2]:
            return True
        else:
            return False
    elif nlist[0] == "<":
        if nlist[1] < nlist[2]:
            return True
        else:
            return False
    elif nlist[0] == "==":
        if nlist[1] == nlist[2]:
            return True
        else:
            return False
    else:
        log("非法字符")
        return True
def ensure(condition, message):
    if condition:
        log('*** 测试成功')
    else:
        log('*** 测试失败:', message)

# 测试函数test_apply_compare()
def test_apply_compare():
    ensure(apply_compare(['<', 1, 2]), 'apply compare 1')
    ensure(apply_compare(['>', 2, 1]), 'apply compare 2')
    ensure(apply_compare(['==', 2, 2]), 'apply compare 3')
    ensure(apply_compare(["===", 2, 2]), 'apply compare 4')
    log('$$$ apply_compare 测试完成')

test_apply_compare()