frontfill or backfill of STRING column at resample() in pandas

Question

is there any methode while doing resampling() to ffill() or bfill() a object column?

Suppose we have:

Date	Sort	Value
2022-10-23 15:40:41	A	1
2022-10-23 18:43:13	B	2
2022-10-24 15:40:41	C	3
2022-10-24 18:43:13	D	4

i would like to have following results with:

df.resample("15min").mean()

Date	Sort	Value
2022-10-23 15:45:00	A	1
2022-10-23 16:00:00	A	1
2022-10-23 16:15:00	A	1
2022-10-23 16:35:00	A	1
…	…	…
2022-10-23 18:00:00	D	1
2022-10-23 18:15:00	D	1
2022-10-23 18:30:00	D	1
2022-10-23 18:45:00	D	1

but it always kick out the "sort column".
would be nice if anyone here can help!

best
M.

Asked By: Mischbot

||

Source

Answer 1

You can specify the aggregation functions for your columns separately, for example:

df = df.resample("15min").agg({"Sort": min, "Value": np.mean}).ffill()

Output:

                    Sort  Value
Date
2022-10-23 15:30:00    A    1.0
2022-10-23 15:45:00    A    1.0
2022-10-23 16:00:00    A    1.0
2022-10-23 16:15:00    A    1.0
2022-10-23 16:30:00    A    1.0
...                  ...    ...
2022-10-24 17:30:00    C    3.0
2022-10-24 17:45:00    C    3.0
2022-10-24 18:00:00    C    3.0
2022-10-24 18:15:00    C    3.0
2022-10-24 18:30:00    D    4.0

Answered By: Tranbi

Answer 2

If need forward filling first valeus per Sort and mean per Value use:

df = df.resample("15min").agg({'Sort':'first', 'Value':'mean'}).ffill()
print (df)
                    Sort  Value
Date                           
2022-10-23 15:30:00    A    1.0
2022-10-23 15:45:00    A    1.0
2022-10-23 16:00:00    A    1.0
2022-10-23 16:15:00    A    1.0
2022-10-23 16:30:00    A    1.0
                 ...    ...
2022-10-24 17:30:00    C    3.0
2022-10-24 17:45:00    C    3.0
2022-10-24 18:00:00    C    3.0
2022-10-24 18:15:00    C    3.0
2022-10-24 18:30:00    D    4.0

[109 rows x 2 columns]

Answered By: jezrael

frontfill or backfill of STRING column at resample() in pandas

Question:

Answers: