pandas merge rows if key is in both 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 join tables in python

display('df1', 'df2', "pd.merge(df1, df2, on='employee')")