通过在现有数据帧中传递一系列日期时间来创建新的数据帧

Question

I have a pandas dataframe called "testset" that looks like this (note that the date column is the index and has been converted to datetime already):

Date                Adj Close
1950-01-03 00:00:00 16.66
1950-01-04 00:00:00 16.85
1950-01-05 00:00:00 16.93
1950-01-06 00:00:00 16.98
1950-01-09 00:00:00 17.08
1950-01-10 00:00:00 17.03
1950-01-11 00:00:00 17.09
1950-01-12 00:00:00 16.76
...

and I have a series of dates (again, converted to datetime) called "triggerdates" that looks like this:

Index   Trigger Date
65      1950-10-04 00:00:00
124     1951-01-02 00:00:00
165     1951-03-02 00:00:00
208     1951-05-03 00:00:00
943     1954-04-12 00:00:00
997     1954-06-29 00:00:00
1053    1954-09-17 00:00:00
1089    1954-11-09 00:00:00

I want to pass the set of dates in the second dataset through the first to create a new dataframe, so that the expected outcome looks something like this:

Date                  Adj Close
1950-10-04 00:00:00   18.64
1951-01-02 00:00:00   19.23
1951-03-02 00:00:00   18.21
1951-05-03 00:00:00   19.21
1954-04-12 00:00:00   20.07
1954-06-29 00:00:00   17.23
1954-09-17 00:00:00   16.12
1954-11-09 00:00:00   20.44
...

When I try and pass it through as below:

df = np.where(triggerdates, testset['Adj Close'], np.nan)

I get the following error:

ValueError: operands could not be broadcast together with shapes (91,) (17369,) () 

As always, any help is appreciated

Answer 1

我认为您正在寻找reindex

testset=testset.reindex(triggerdates)