Question

我有两个数据帧A和B，其中A具有连续数据值，B具有每周一次的值。如何合并两个数据帧，以便B数据帧中的值重复，直到它在A数据帧中到达周末。

实施例：＆＃39; A＆＃39; Dataframe看起来像这样

Date        Price
2018-01-03  61.63
2018-01-01  60.42
2017-12-29  60.42
2017-12-28  59.84
2017-12-27  59.64
2017-12-26  59.97
2017-12-22  58.47
2017-12-21  58.36
2017-12-20  58.09
2017-12-19  57.97
2017-12-18  57.92
2017-12-17  57.79

和＆＃39; B＆＃39; Dataframe看起来像这样

Week        Week Price
2017-12-29  9782 
2017-12-22  9754
2017-12-15  9789

我期待输出如下：

Date        Price  Week Price
2018-01-03  61.63  9782
2018-01-01  60.42  9782
2017-12-29  60.42  9782
2017-12-28  59.84  9754
2017-12-27  59.64  9754
2017-12-26  59.97  9754
2017-12-22  58.47  9754
2017-12-21  58.36  9789
2017-12-20  58.09  9789
2017-12-19  57.97  9789
2017-12-18  57.92  9789
2017-12-17  57.79  9789

Answer 1

我们可以使用merge_asof（df1是你的A df2是你的B）

df=pd.merge_asof(df1.sort_values('Date'),df2.sort_values('Week'),left_on='Date',right_on='Week').sort_index(ascending=False).drop('Week',1)
df
Out[232]: 
         Date  Price  WeekPrice
11 2018-01-03  61.63       9782
10 2018-01-01  60.42       9782
9  2017-12-29  60.42       9782
8  2017-12-28  59.84       9754
7  2017-12-27  59.64       9754
6  2017-12-26  59.97       9754
5  2017-12-22  58.47       9754
4  2017-12-21  58.36       9789
3  2017-12-20  58.09       9789
2  2017-12-19  57.97       9789
1  2017-12-18  57.92       9789
0  2017-12-17  57.79       9789

在某些日期之间重复Pandas中的值

1 个答案: