python - for 循环有 7 个值可以滚动，但我得到 8 个输出

Question

我的代码如下:

smallest_so_far = -1
print("Before:", smallest_so_far)
for the_num in [9, 41, 12, 3, 74, 15, -3]:
    if the_num < smallest_so_far:
        print(the_num, "is smaller than", smallest_so_far)
        smallest_so_far = the_num
    print(the_num, "is not smaller than", smallest_so_far)

print("After:", smallest_so_far)

但是，如果它之前已经检查过一行，为什么最后还要用 -3 再次检查 -3 呢？我认为它应该滚动一次“in”中的每个值。

输出:

Before: -1
9 is not smaller than -1
41 is not smaller than -1
12 is not smaller than -1
3 is not smaller than -1
74 is not smaller than -1
15 is not smaller than -1
-3 is smaller than -1
-3 is not smaller than -3
After: -3

Answer 1

你需要一个 else .代码仍将运行

print(the_num, "is not smaller than", smallest_so_far)

无论如何。

所以你会把你的代码改成

smallest_so_far = -1
print("Before:", smallest_so_far)
for the_num in [9, 41, 12, 3, 74, 15, -3]:
    if the_num < smallest_so_far:
        print(the_num, "is smaller than", smallest_so_far)
        smallest_so_far = the_num
    else:
        print(the_num, "is not smaller than", smallest_so_far)

print("After:", smallest_so_far)