将日期时间列表与Python中的日期时间进行比较

Question

我有一个日期时间对象列表,并希望找到在特定时间范围内的对象:

import datetime

dates = [ datetime.datetime(2007, 1, 2, 0, 1),
          datetime.datetime(2007, 1, 3, 0, 2),
          datetime.datetime(2007, 1, 4, 0, 3),
          datetime.datetime(2007, 1, 5, 0, 4),
          datetime.datetime(2007, 1, 6, 0, 5),
          datetime.datetime(2007, 1, 7, 0, 6) ]
#in reality this is a list of over 25000 dates

mask = (dates>datetime.datetime(2007,1,3)) & \
       (dates<datetime.datetime(2007,1,6))

但是,这会导致以下错误:"TypeError:无法将datetime.datetime与列表进行比较"

我该如何修复我的代码？

Answer 1

您可以使用numpy.array您描述的语法(但不是列表)屏蔽a :

import numpy as np

date1 = np.array(dates)
mask = (dates1 > datetime.datetime(2007,1,3)) & \
       (dates1 < datetime.datetime(2007,1,6))

In [14]: mask
Out[14]: array([False,  True,  True,  True, False, False], dtype=bool)

In [15]: dates1[mask]
Out[15]: array([2007-01-03 00:02:00, 2007-01-04 00:03:00, 2007-01-05 00:04:00], dtype=object)

(因为这个问题被标记为numpy,大概这就是你想要的.)

Answer 2

如果dates列表按排序顺序排列,则可以使用以下bisect模块:

>>> import bisect
>>> bisect.bisect_right(dates, datetime.datetime(2007,1,3))
1
>>> bisect.bisect_left(dates, datetime.datetime(2007,1,6))
4

该.bisect_*函数返回的索引到dates列表:

>>> lower = bisect.bisect_right(dates, datetime.datetime(2007,1,3))
>>> upper = bisect.bisect_left(dates, datetime.datetime(2007,1,6))
>>> mask = dates[lower:upper]
>>> mask
[datetime.datetime(2007, 1, 3, 0, 2), datetime.datetime(2007, 1, 4, 0, 3), datetime.datetime(2007, 1, 5, 0, 4)]

Answer 3

import datetime

dates = [ datetime.datetime(2007, 1, 2, 0, 1),
          datetime.datetime(2007, 1, 3, 0, 2),
          datetime.datetime(2007, 1, 4, 0, 3),
          datetime.datetime(2007, 1, 5, 0, 4),
          datetime.datetime(2007, 1, 6, 0, 5),
          datetime.datetime(2007, 1, 7, 0, 6) ]


within = [date for date in dates if datetime.datetime(2007,1,3) < date < datetime.datetime(2007,1,6)]

收益率:

[datetime.datetime(2007, 1, 3, 0, 2), 
 datetime.datetime(2007, 1, 4, 0, 3), 
 datetime.datetime(2007, 1, 5, 0, 4)]