我在下面有两个时间序列。日期时间索引是 TZ 感知的。
df1:五分钟间隔
value_1
Timestamp
2009-04-01 10:50:00+09:30 50
2009-04-05 11:55:00+09:30 55
2009-04-23 16:00:00+09:30 0
2009-05-03 10:50:00+09:30 50
2009-05-07 11:55:00+09:30 55
2009-05-11 16:00:00+09:30 0
2009-07-04 02:05:00+09:30 5
2009-07-21 09:10:00+09:30 10
2009-07-30 12:15:00+09:30 15
2010-09-02 11:25:00+09:30 25
2010-09-22 15:30:00+09:30 30
2010-09-30 06:15:00+09:30 15
2010-12-06 11:25:00+09:30 25
2010-12-22 15:30:00+09:30 30
2010-12-28 06:15:00+09:30 15
df2:groupby('Month')
从不同数据集获取的每月间隔。
value_2
Timestamp
2009-04-30 00:00:00+09:30 23
2009-07-31 00:00:00+09:30 28
2010-12-31 00:00:00+09:30 23
我想按索引合并两个数据集。如果 df1 中的任何记录与 df2 的月份相同,则应包含在最终结果中。预期结果如下。
value_1 value_2
Timestamp
2009-04-01 10:50:00+09:30 50 23
2009-04-05 11:55:00+09:30 55 23
2009-04-23 16:00:00+09:30 0 23
2009-07-04 02:05:00+09:30 5 28
2009-07-21 09:10:00+09:30 10 28
2009-07-30 12:15:00+09:30 15 28
2010-12-06 11:25:00+09:30 25 23
2010-12-22 15:30:00+09:30 30 23
2010-12-28 06:15:00+09:30 15 23
这是我的尝试。
result = pd.concat([df1, df2], axis=1)
# this combines the datasets, but not like expected, also by including join="outer". With join="inner", no data shown.
result = pd.merge(df1, df2, left_on='value_1', right_index=True)
# this return ValueError: You are trying to merge on Int64 and datetime64[ns, Australia/North] columns. If you wish to proceed you should use pd.concat
# Using @Ben.T
mt_hMF = df1.merge( df2.reset_index().set_index(df2.index.floor('M')),
how='left', left_index=True, right_index=True).set_index('Timestamp')
# This gives ValueError: <MonthEnd> is a non-fixed frequency
试试这个,使用strftime
为两个数据帧创建一个临时合并键:
df1.reset_index()
.assign(yearmonth=df1.index.strftime('%Y%m'))
.merge(df2.assign(yearmonth=df2.index.strftime('%Y%m')))
.set_index('Timestamp')
.drop('yearmonth', axis=1)
输出:
value_1 value_2
Timestamp
2009-04-01 10:50:00+09:30 50 23
2009-04-05 11:55:00+09:30 55 23
2009-04-23 16:00:00+09:30 0 23
2009-07-04 02:05:00+09:30 5 28
2009-07-21 09:10:00+09:30 10 28
2009-07-30 12:15:00+09:30 15 28
2010-12-06 11:25:00+09:30 25 23
2010-12-22 15:30:00+09:30 30 23
2010-12-28 06:15:00+09:30 15 23