Impute 1 if previous row of 'days' column is between 0 & 7

[JaneTan]

Hi,

Basically, I want to impute 1 in 'Check' column if the previous row of 'days' is >=0 and <7.
I wrote the below code, but it only looks at current row of 'days' column.

Thank you

def impute(df):
    if df['days']>=0 and df['days']<7:
        return 1
    
df['check']=df.apply(impute, axis=1)

Current output
Weekly MonthEnd days check
Period
1989-01-20 3 1989-01-31 11 NaN
1989-01-27 4 1989-01-31 4 1.0
1989-02-03 2 1989-02-28 25 NaN
1989-02-10 5 1989-02-28 18 NaN
1989-02-17 3 1989-02-28 11 NaN
1989-02-24 5 1989-02-28 4 1.0
1989-03-03 5 1989-03-31 28 NaN

Desired Output

Weekly MonthEnd days check
Period
1989-01-20 3 1989-01-31 11 NaN
1989-01-27 4 1989-01-31 4 NaN
1989-02-03 2 1989-02-28 25 1.0
1989-02-10 5 1989-02-28 18 NaN
1989-02-17 3 1989-02-28 11 NaN
1989-02-24 5 1989-02-28 4 NaN
1989-03-03 5 1989-03-31 28 1.0

[Larz60+]

input df please

[deanhystad]

You can shift the days column.

import pandas as pd
df = pd.DataFrame({"Count":range(5)})
df[Shifted'] = df['Count'].shift(1)
print(df)

Output:
   Count  Shifted
0      0  NaN
1      1  0.0
2      2  1.0
3      3  2.0
4      4  3.0

Then you could use the shifted column in your function