距给定日期还剩多少时间（天、小时、分钟、秒）

Question

我正在尝试在 python 中制作某种“截止日期时钟”。 关于时差计算的话题很多，我跟着一些并整理了这种代码：

import datetime
from dateutil.relativedelta import relativedelta

# Get current time:
today = datetime.date.today()
timenow = datetime.datetime.now()
current_time = str(today) + " " + str(timenow.strftime("%H:%M:%S"))

# Set deadline:
deadline = "2019-12-12 15:00:00"

# Calculate difference:
start = datetime.datetime.strptime(current_time,'%Y-%m-%d %H:%M:%S')
ends = datetime.datetime.strptime(deadline, '%Y-%m-%d %H:%M:%S')
diff = relativedelta(ends, start)

print("Now: " + current_time)
print("Deadline: " + deadline)

print(str(diff.days) + " days. " 
      + str(diff.hours) + " hours. " 
      + str(diff.minutes) + " minutes. " 
      + str(diff.seconds) + " seconds. " 
      )

但问题是，它总是会显示最多一个月的差异......那么问题出在哪里？

Answer 1

只需用结束日期减去开始日期即可。

import datetime
today = datetime.date.today()
timenow = datetime.datetime.now()
deadline = "2019-12-12 15:00:00"
current_time = str(today) + " " + str(timenow.strftime("%H:%M:%S"))
start = datetime.datetime.strptime(current_time,'%Y-%m-%d %H:%M:%S')
ends = datetime.datetime.strptime(deadline, '%Y-%m-%d %H:%M:%S')

print(start - ends)

正如 cmets 中所建议的，您实际上不需要单独使用 .today() 和 .now()，.now() 将当前日期和时间作为日期时间对象本身返回。

import datetime
timenow = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
deadline = "2019-12-12 00:00:00"
start = datetime.datetime.strptime(timenow,'%Y-%m-%d %H:%M:%S')
ends = datetime.datetime.strptime(deadline, '%Y-%m-%d %H:%M:%S')
print(start - ends)