datetime相加减

当前日期时间

1. import datetime

2. print datetime.datetime.now()

3. # 2018-05-08 16:53:30.101000

格式化时间

1. import datetime

2. print datetime.datetime.now().strftime("%Y-%m-%d %H:%M")

3. # 2018-05-08 16:54

多加一天

1. import datetime

2. print (datetime.datetime.now()+datetime.timedelta(days=1)).strftime("%Y-%m-%d %H:%M:%S")

3. # 2018-05-09 16:56:07

减一天

1. import datetime

2. print (datetime.datetime.now()+datetime.timedelta(days=-1)).strftime("%Y-%m-%d %H:%M:%S")

3. # 2018-05-07 16:56:59

可以把days改为hours minutes，就可以提前XX小时/分钟了。

timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[,
hours[, weeks]]]]]]])

减去一年

1. import datetime

2. from dateutil.relativedelta import relativedelta

3. d = datetime.datetime.strptime('20180131', '%Y%m%d')

4. print(d) // 2018-01-31 00:00:00

5. print((d - relativedelta(years=1)).strftime('%Y%m%d')) // 20170131