Python 从上一个结果传递值

我想计算一个变量在时间间隔之间的间隔

以下是计算示例：

Count |差距|差距结果|评估
----------------------------------------
19   | 15-5   |   10         |   10
18   | 15-3   |   12         |   10-12 = -2
17   | 15-4   |   11         |   12-11 = 1

我不知道如何表达它。请给我一些建议

number = [1,2,3,4,5,6,7]
goal = 15
count = 20
def step (self)
    while count > 0:
          count -= 1
          gap = [goal - (random.choice(number))]
          previous_gap = gap from (count - 1) # I don't know how to express this
          evaluate = previous_gap - gap

---

您还需要存储以前的间隙；首先将其设置为0。您不需要列表，而是在这里处理单个数字：

goal = 15
count = 20
previous_gap = evaluate = 0

while count > 0:
    count -= 1
    gap = goal - random.choice(number)
    if previous_gap:
        evaluate = previous_gap - gap
    # remember the gap for the next step
    previous_gap = gap

---

如果你告诉我们预期结果会是什么，那会有帮助的。你还没有真正定义你所说的“差距”是什么意思？你为什么要尝试减去列表<代码>评估=先前的差距-差距@MartijnPieters问题已编辑。请指教