Python--datetime 模块

1.timedelta：时间间隔

from datetime import *

In [8]: datetime.now()
Out[8]: datetime.datetime(2017, 10, 7, 11, 52, 25, 911519)

In [7]: datetime.now()+timedelta(days=1)
Out[7]: datetime.datetime(2017, 10, 8, 11, 52, 16, 199424)

datetime.now()+timedelta(days=1)

timedelta:时间间隔
 |  days
 |      Number of days.
 |  
 |  microseconds
 |      Number of microseconds (>= 0 and less than 1 second).
 |  
 |  seconds
 |      Number of seconds (>= 0 and less than 1 day).

2.pytz：时区问题

import pytz
from datetime import datetime

# 获取带时区的当前时间
>>> tz = pytz.timezone('Asia/Shanghai')
>>> tz
<DstTzInfo 'Asia/Shanghai' LMT+8:06:00 STD>

>>> datetime.now(tz)
datetime.datetime(2019, 4, 26, 10, 5, 9, 938765, tzinfo=<DstTzInfo 'Asia/Shanghai' CST+8:00:00 STD>)

# 创建带时区的时间
>>> datetime(2019, 4, 16, 9, 30, tzinfo=tz)
datetime.datetime(2019, 4, 16, 9, 30, tzinfo=<DstTzInfo 'Asia/Shanghai' LMT+8:06:00 STD>)
# 这里差了8分钟， 解决方法， tz.localize(datetime object)
>>> d = datetime(2019, 4, 16, 9, 30)
>>> tz.localize(d)
datetime.datetime(2019, 4, 16, 9, 30, tzinfo=<DstTzInfo 'Asia/Shanghai' CST+8:00:00 STD>)

# 转换时区
>>> t = datetime.now(tz)
>>> t
datetime.datetime(2019, 4, 26, 10, 8, 45, 288142, tzinfo=<DstTzInfo 'Asia/Shanghai' CST+8:00:00 STD>)
>>> t.astimezone(pytz.utc)
datetime.datetime(2019, 4, 26, 2, 8, 45, 288142, tzinfo=<UTC>)