using on to merge two columns of a dataframe python code example

Example 1: 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'])

Example 2: how to merge two dataframes

df_merge_col = pd.merge(df_row, df3, on='id')

df_merge_col