如何在python中强制datetime保留0微秒

您可以使用手动设置格式 strftime :

>>> starttime = datetime(year=2018, month=2, day=15, hour=8, minute=0, second=0, microsecond=0)
>>> starttime.strftime("%Y-%m-%dT%H:%M:%S.%f")
'2018-02-15T08:00:00.000000'

Vs:

>>> starttime.isoformat()
'2018-02-15T08:00:00'

以及:

>>> starttime = datetime(year=2018, month=2, day=15, hour=8, minute=0, second=0, microsecond=1)
>>> starttime.strftime("%Y-%m-%dT%H:%M:%S.%f")
'2018-02-15T08:00:00.000001'
>>> starttime.isoformat()
'2018-02-15T08:00:00.000001'

(确认在Python3.6之后工作,在2.7上不工作)

isoformat() 接受参数:

datetime.datetime(2020, 2, 20, 0, 0, 0, 0).isoformat(timespec='microseconds')
Out[17]: '2020-02-20T00:00:00.000000'

可能的值:

    'auto': the default behaviour
    'hours': '{:02d}'
    'minutes': '{:02d}:{:02d}'
    'seconds': '{:02d}:{:02d}:{:02d}'
    'milliseconds': '{:02d}:{:02d}:{:02d}.{:03d}'
    'microseconds': '{:02d}:{:02d}:{:02d}.{:06d}'

只需对标准字符串转换进行少量操作,即可完成以下操作:

代码:

def force_microseconds(a_datetime):
    dt_str = a_datetime.isoformat()
    if '.' not in dt_str:
        dt_str += '.000000'
    return dt_str

测试代码:

import datetime as dt

starttime = dt.datetime(year=2018, month=2, day=15, hour=8,
                        minute=0, second=0, microsecond=0)

print(force_microseconds(starttime))
print(force_microseconds(starttime + dt.timedelta(microseconds=1) ))

结果:

2018-02-15T08:00:00.000000
2018-02-15T08:00:00.000001