Compare 2 columns in same excel sheet in pandas

Question

I want to compare the two columns in an excel sheet. names of the columns, such as file 1 and file 2. Want to add a third column with the name "diff" using the Excel formula "countifs" utilizing these two columns. If the entries in the file 1 and file 2 columns match, the diff column value should be 0 (Zero), otherwise, it should be 1. But the outcome is not what I expected. Could you please assist anyone?

here is my inputs :

   file_1    file_2 
    G          G
    A          B
    C          F
    E          H
    A          C
    H          E

Output Dataframe :

    file_1       file_2       diff 
     G          G              0
     A          B              1
     C          F              1
     E          H              0
     A          C              0
     H          E              0

Sample code :

     df = pd.read_excel('file1.xlsx')
     df1 = df[df['file_1'].isin(df['file_2'])]
     df['diff'] = df1
     print(df)

Answer 1

Try this:

import pandas as pd
import numpy as np
df['diff'] = np.where(df['file_1'] == df['file_2'] , '0', '1')