英文:
How many calendar days elapsed since given date?
问题
我需要找出自指定日期以来经过了多少个日历日。当我使用以下方法时，即使日期是今天，它也会给我返回-1：
>>> from datetime import datetime
>>> t = datetime.fromisoformat('2023-03-09 08:55:11')
>>> (t - datetime.today()).days
-1
然而，正确的答案应该是0。
如果我在00:00:01时询问，而日期是昨天的23:59:59，它应该返回1天。但是对于任何今天的日期，答案都应该是0。
我该如何做到这一点？
英文:
I need to find how many calendar days elapsed sice given date. When I use the following, it gives me -1 even when the date is today:
>>> from datetime import datetime
>>> t = datetime.fromisoformat('2023-03-09 08:55:11')
>>> (t - datetime.today()).days
-1
Whereas the correct answer should be 0.
If I ask at 00:00:01, and the date was yesterday at 23:59:59, it should give me 1 day. But anything today should be 0.
How can I do that?
答案1
得分: 1
将这两个值都转换为日期，而不是日期时间。
就像将0.9与1.1进行比较，希望结果为1一样。首先将它们都转换为整数将给出0和1，差值为1。
因此，比较日期，而不是日期时间...
from datetime import datetime, date
x = datetime.fromisoformat('2023-03-09 08:55:11')
y = datetime.fromisoformat('2023-03-10 07:00:00')
print((y - x).days)
print((y.date() - x.date()).days)
print()
y = datetime.fromisoformat('2023-03-10 09:00:00')
print((y - x).days)
print((y.date() - x.date()).days)
演示链接：https://trinket.io/python3/013ac6c02a
英文:
Convert both values to dates instead of datetimes.
It's like comparing 0.9 to 1.1 and wanting the result to be 1. Converting them both to integers first would give 0 and 1 with a difference of 1.
So, compare dates, not datetimes...
from datetime import datetime, date
x = datetime.fromisoformat('2023-03-09 08:55:11')
y = datetime.fromisoformat('2023-03-10 07:00:00')
print((y - x).days)
print((y.date() - x.date()).days)
print()
y = datetime.fromisoformat('2023-03-10 09:00:00')
print((y - x).days)
print((y.date() - x.date()).days)
答案2
得分: 0
from datetime import datetime, date
given_date = datetime.fromisoformat('2023-03-09 08:55:11')
today = datetime.now().date() # 获取当前日期，不包括时间
elapsed_days = (today - given_date.date()).days
print(elapsed_days)
英文:
from datetime import datetime, date
given_date = datetime.fromisoformat('2023-03-09 08:55:11')
today = datetime.now().date() # get current date without time
elapsed_days = (today - given_date.date()).days
print(elapsed_days)
答案3
得分: -3
你得到负数结果的原因是你从一个未来日期减去当前日期。你可以使用math.abs，或者只需：
t= datetime.fromisoformat('2023-03-01')
elapsed_days = (datetime.today() - t).days
print(elapsed_days)
英文:
The reason you are getting a negative result is that you are subtracting the current date from a future date. You can use math.abs, or just:
t= datetime.fromisoformat('2023-03-01')
elapsed_days = (datetime.today() - t).days
print(elapsed_days)
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