Compare two Dataframe columns and retrive the mismatched columns in a new column

Question

I am trying to compare two dataframes and create one column in the first dataframe says that mismatched columns. attaching the Dataframe images and expected output images below. Could I get some help here

enter image description here attaching the expected outputs here.Need one column says that names of all mismatched columns

Answer 1

Assuming aligned indices, you can use:

df1['mismatch'] = df1.ne(df2).dot(df1.columns+',').str[:-1]

Alternatively:

out = (df1.ne(df2).reset_index().melt('index')
       .query('value').groupby('index')
       ['variable'].agg(','.join)
      )

df1['mismatch'] = out

Example output:

   A  B  C mismatch
0  1  2  3      A,B
1  4  5  6        A
2  7  8  9         

Used inputs:

# df1
   A  B  C
0  1  2  3
1  4  5  6
2  7  8  9

# df2
   A  B  C
0  0  0  3
1  0  5  6
2  7  8  9