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

[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