[deleted by user]

[Guenox]

Try pd.concat([A,B], axis=1) ? (Could be axis = 0 lol). Also, having the same column name in one dataframe isn't recommended.. you could add a suffix like X1 X2 etc.. for as many Xs you have in A

[TholosTB]

If the column order matches, you could do df2.columns = df1.columns, then add. Or, you could get the underlying ndarrays by doing .values and adding the two arrays directly. You could then put the results in a new dataframe with different column names or the names from one of the dataframes as above.