python - 为什么日期时间之间的差异不对称？

Question

当我从结束时间中减去开始时间时，我得到10 days, 7:39:11答案，而当从开始时间中减去结束时间时，答案是-11 days, 16:20:49。为什么会这样？结果应该与负号相同，不是吗？

import datetime

datetime_start = datetime.datetime(2021, 6, 13, 3, 31, 47, 466744)
datetime_end = datetime.datetime(2021, 6, 23, 11, 10, 58, 466744)

date_diff = datetime_end - datetime_start
print(type(date_diff))
print(date_diff)

date_diff = datetime_start - datetime_end
print(type(date_diff))
print(date_diff)

标签： pythondatetimetimedelta