我有一个熊猫DataFrame系列时差,看起来像:
print(delta_t)
1 0 days 00:00:59
3 0 days 00:04:22
6 0 days 00:00:56
8 0 days 00:01:21
19 0 days 00:01:09
22 0 days 00:00:36
...
(完整的DataFrame包含一堆我丢弃的NaN)。
我想知道哪个delta_t小于1天1小时1分钟, 所以我尝试了:
delta_t_lt1day = delta_t[np.where(delta_t < 30.)]
但是得到一个:
TypeError: cannot compare a TimedeltaIndex with type float
没有什么帮助?!?!
答案 0 :(得分:3)
假设您的系列采用timedelta
格式,则可以跳过np.where
,并使用类似以下内容的索引,在其中使用适当的单位将实际值与其他时间增量进行比较:
delta_t_lt1day = delta_t[delta_t < pd.Timedelta(1,'D')]
delta_t_lt1hour = delta_t[delta_t < pd.Timedelta(1,'h')]
delta_t_lt1minute = delta_t[delta_t < pd.Timedelta(1,'m')]
您将获得以下系列:
>>> delta_t_lt1day
0
1 00:00:59
3 00:04:22
6 00:00:56
8 00:01:21
19 00:01:09
22 00:00:36
Name: 1, dtype: timedelta64[ns]
>>> delta_t_lt1hour
0
1 00:00:59
3 00:04:22
6 00:00:56
8 00:01:21
19 00:01:09
22 00:00:36
Name: 1, dtype: timedelta64[ns]
>>> delta_t_lt1minute
0
1 00:00:59
6 00:00:56
22 00:00:36
Name: 1, dtype: timedelta64[ns]
答案 1 :(得分:1)
您可以使用TimeDelta类:
import pandas as pd
deltas = pd.to_timedelta(['0 days 00:00:59',
'0 days 00:04:22',
'0 days 00:00:56',
'0 days 00:01:21',
'0 days 00:01:09',
'0 days 00:31:09',
'0 days 00:00:36'])
for e in deltas[deltas < pd.Timedelta(value=30, unit='m')]:
print(e)
输出
0 days 00:00:59
0 days 00:04:22
0 days 00:00:56
0 days 00:01:21
0 days 00:01:09
0 days 00:00:36
请注意,此过滤器会按预期淘汰'0 days 00:31:09'
。表达式pd.Timedelta(value=30, unit='m')
创建30分钟的时间增量。