python - Python 中奇怪的日期时间差异

Question

谁能告诉我为什么 python 显示两个日期之间相差 1310 秒？

import datetime
time1=datetime.datetime(2016,12,8,20,5,0)
time2=datetime.datetime(2016,12,7,19,43,10)
timediff=time1-time2
print(timediff)
print(timediff.seconds)

>1 day, 0:21:50
>1310

Answer 1

如您所见here timedelta 对象具有三个字段:days； 秒；和 微秒。或者按照文档中的说明:

class datetime.timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)

(...)

Only days, seconds and microseconds are stored internally. Arguments are converted to those units:

• A millisecond is converted to 1000 microseconds.
• A minute is converted to 60 seconds.
• An hour is converted to 3600 seconds.
• A week is converted to 7 days.

(添加格式)

尽管构造函数是 timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0) 并因此提供了输入方法小时，因此它将 分钟、小时 等全部转换为秒。构造函数将如下所示:

def __init__(self, days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0):
    self.microseconds = microseconds+1000*milliseconds
    self.seconds = seconds+60*minutes+3600*hours+self.microseconds//1000000
    self.microseconds %= 1000000
    self.days = days+7*weeks+self.seconds//86400
    self.seconds %= 86400

(但可能更高级一些，等等)

所以这意味着 .seconds 实际上是模日，没有微秒。

但是您可以使用 timediff.total_seconds返回总秒数:

>>> timediff.total_seconds()
87710.0

所以 total_seconds() 基本上是:

def total_seconds(self):
    return 86400.0*self.days+self.seconds+1e-6*self.microseconds
    #      ^ number of seconds in a day   ^
    #                                     | 1 micro is 1e-6

如果将 1310 除以 60，您将看到它返回:

>>> 1310/60 # obtain number of minutes
21.833333333333332
>>> 1310%60 # obtain number of seconds  (without minutes)
50

所以21分50秒