将日期时间向下舍入到前一小时

Question

如何将日期时间舍入到前一小时？例如：

 print datetime.now().replace(microsecond=0)
>> 2017-01-11 13:26:12.0

四舍五入到前一小时： 2017-01-11 12:00:00.0

原文由 DougKruger 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

如果您想 向下舍入到小时，您可以简单地将 microsecond 、 second 和 minute 替换为零：

 print(datetime.now().replace(microsecond=0, second=0, minute=0))

---

If you want to round down to the previous hour (as stated in the example 2017-01-11 13:26:12.0 to 2017-01-11 12:00:00.0 ), replace microsecond , second and minute 带零，然后减去一小时：

 from datetime import datetime, timedelta

print(datetime.now().replace(microsecond=0, second=0, minute=0) - timedelta(hours=1))

外壳中的示例：

 $ python3
Python 3.5.2 (default, Nov 17 2016, 17:05:23)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from datetime import datetime, timedelta
>>> print(datetime.now().replace(microsecond=0, second=0, minute=0) - timedelta(hours=1))
2017-01-11 16:00:00

原文由 Willem Van Onsem 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

from datetime import datetime, timedelta

n = datetime.now() - timedelta(hours=1)
new_date = datetime(year=n.year, month=n.month, day=n.day, hour=n.hour)

原文由 gipsy 发布，翻译遵循 CC BY-SA 3.0 许可协议