merging and join in 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: merge dataframe

In [46]: result = pd.merge(left, right, how="right", on=["key1", "key2"])