How to check the nearest matching value between two fields in same table and add data to the third field using Pandas?

Question

I have one table:

Index	Month_1	Month_2	Paid
01	12	10
02	09	03
03	02	04
04	01	08

The output should be:

Index	Month_1	Month_2	Paid
01	12	10	Yes
02	09	03
03	02	04	Yes
04	01	08

Logic: Add 'Yes' to the Paid field whose Month_1 and Month_2 are nearby

Answer 1

You can subtract columns, get absolute values and compare if equal or less like threshold, eg 2 and then set values in numpy.where :

df['Paid'] = np.where(df['Month_1'].sub(df['Month_2']).abs().le(2), 'Yes','')
print (df)
  Index  Month_1  Month_2 Paid
0    01       12       10  Yes
1    02        9        3     
2    03        2        4  Yes
3    04        1        8