Closest value join with pandas

I have a left table

and a right table

And I would like to get the final table

For this, I would like to use a function (merge or other more advanced verions like merge_asof or merge_ordered) in pandas

• the match for v1 and v2 is exact
• then the match for v3 is approximate, with the closest values.

>Solution :

Try with merge_asof

out = pd.merge_asof(df1.sort_values('v3'),
                    df2.sort_values('v3'), 
                    by = ['v1','v2'], 
                    on = 'v3', 
                    direction = 'nearest')

Out[10]: 
  v1 v2  v3    c
0  a  c  11  100
1  a  d  22  200
2  b  c  33  200