pd.merge(df1, df2, left_index=True, right_index=True, how='outer')
obj_df = df.select_dtypes(include=[np.object])
num_df = df.select_dtypes(exclude=[np.object])
obj_df.head(1).combine_first(obj_df.tail(1)).join(num_df.head(1).add(num_df.tail(1)))
df = pd.concat([T1.reset_index(drop=True),T2.reset_index(drop=True)], axis=1)