PYTHON

pd merge

'''
An example of merge between two dfs where left_df's keys are used 
by setting how='left'.
You can also use "left_on" and "right_on" instead of "on" if the two dfs are to 
be merged on different columns.
'''
pd.merge(left_df, right_df, on='column_to_merge_on', how='left')

pandas merge df

In [41]: result = pd.merge(left, right, on="key")

pd df merge

df1.merge(df2, left_on='lkey', right_on='rkey',
...           suffixes=('_left', '_right'))

pd df merge

df1.merge(df2, left_on='lkey', right_on='rkey')