基于@Attaque的精彩回答，我提出了一个更短的简化版本的日期时差计算器:

seconds_mapping = {
    'y': 31536000,
    'm': 2628002.88, # this is approximate, 365 / 12; use with caution
    'w': 604800,
    'd': 86400,
    'h': 3600,
    'min': 60,
    's': 1,
    'mil': 0.001,
}

def get_duration(d1, d2, interval, with_reminder=False):
    if with_reminder:
        return divmod((d2 - d1).total_seconds(), seconds_mapping[interval])
    else:
        return (d2 - d1).total_seconds() / seconds_mapping[interval]

我改变了它，以避免声明重复的函数，删除了漂亮的打印默认间隔，并增加了对毫秒、周和ISO月的支持(简单地说，月只是一个近似，基于每个月等于365/12的假设)。

生产:

d1 = datetime(2011, 3, 1, 1, 1, 1, 1000)
d2 = datetime(2011, 4, 1, 1, 1, 1, 2500)

print(get_duration(d1, d2, 'y', True))      # => (0.0, 2678400.0015)
print(get_duration(d1, d2, 'm', True))      # => (1.0, 50397.12149999989)
print(get_duration(d1, d2, 'w', True))      # => (4.0, 259200.00149999978)
print(get_duration(d1, d2, 'd', True))      # => (31.0, 0.0014999997802078724)
print(get_duration(d1, d2, 'h', True))      # => (744.0, 0.0014999997802078724)
print(get_duration(d1, d2, 'min', True))    # => (44640.0, 0.0014999997802078724)
print(get_duration(d1, d2, 's', True))      # => (2678400.0, 0.0014999997802078724)
print(get_duration(d1, d2, 'mil', True))    # => (2678400001.0, 0.0004999997244524721)

print(get_duration(d1, d2, 'y', False))     # => 0.08493150689687975
print(get_duration(d1, d2, 'm', False))     # => 1.019176965856293
print(get_duration(d1, d2, 'w', False))     # => 4.428571431051587
print(get_duration(d1, d2, 'd', False))     # => 31.00000001736111
print(get_duration(d1, d2, 'h', False))     # => 744.0000004166666
print(get_duration(d1, d2, 'min', False))   # => 44640.000024999994
print(get_duration(d1, d2, 's', False))     # => 2678400.0015
print(get_duration(d1, d2, 'mil', False))   # => 2678400001.4999995

要得到小时、分和秒，你可以这样做

>>> import datetime
>>> first_time = datetime.datetime.now()
>>> later_time = datetime.datetime.now()
>>> difference = later_time - first_time
>>> m, s = divmod(difference.total_seconds(), 60)
>>> print("H:M:S is {}:{}:{}".format(m//60, m%60, s))

如果a, b是datetime对象，那么在Python 3中查找它们之间的时间差:

from datetime import timedelta

time_difference = a - b
time_difference_in_minutes = time_difference / timedelta(minutes=1)

在早期的Python版本中:

time_difference_in_minutes = time_difference.total_seconds() / 60

如果a, b是天真的datetime对象，例如datetime.now()返回的，那么如果对象表示具有不同UTC偏移量的本地时间，例如DST转换前后或过去/未来日期，则结果可能是错误的。更多细节:查找datetimes之间是否已经过了24小时- Python。

要获得可靠的结果，请使用UTC时间或时区感知的datetime对象。

import datetime
date = datetime.date(1, 1, 1)
#combine a dummy date to the time
datetime1 = datetime.datetime.combine(date, start_time)
datetime2 = datetime.datetime.combine(date, stop_time)  
#compute the difference
time_elapsed = datetime1 - datetime2

Start_time——> datetime对象的开始时间 End_time——> datetime对象的结束时间

我们不能直接减去datetime。时间对象 因此，我们需要添加一个随机日期(我们使用combine) 或者你可以用“today”来代替(1,1,1)

希望这能有所帮助

这就是我如何获得两个datetime之间经过的小时数。datetime对象:

before = datetime.datetime.now()
after  = datetime.datetime.now()
hours  = math.floor(((after - before).seconds) / 3600)

Python 2.7新增了timedelta实例方法.total_seconds()。在Python文档中，这相当于(td。微秒+ (td。秒+ td。天* 24 * 3600)* 10**6)/ 10**6。

参考:http://docs.python.org/2/library/datetime.html # datetime.timedelta.total_seconds

>>> import datetime
>>> time1 = datetime.datetime.now()
>>> time2 = datetime.datetime.now() # waited a few minutes before pressing enter
>>> elapsedTime = time2 - time1
>>> elapsedTime
datetime.timedelta(0, 125, 749430)
>>> divmod(elapsedTime.total_seconds(), 60)
(2.0, 5.749430000000004) # divmod returns quotient and remainder
# 2 minutes, 5.74943 seconds