merge multiple column with single pandas code example

Example 1: merge two dataframes based on column

df_outer = pd.merge(df1, df2, on='id', how='outer')

df_outer

Example 2: pd merge on multiple columns

new_df = pd.merge(A_df, B_df,  how='left', left_on=['A_c1','c2'], right_on = ['B_c1','c2'])