Proper way to add a column form one table to another

Question

I have two data frames here

import pandas as pd
import numpy as np

df1 = pd.DataFrame({'id':[1,2,3,2,5], 'grade':[3,5,3,2,1]})
df2 = pd.DataFrame({'id':[1,2,3], 'final':[6,4,2]})

Now I want to take final column from df2 and add to df1 based on the id column. Here is the desired output

output = pd.DataFrame({'id':[1,2,3,2,5],'grade':[3,5,3,2,1], 'final':[6,4,2,4,np.nan]})

What approach can I try?

Answer 1

One way to do it is by using map

df1['final'] = df1['id'].map(df2.set_index('id')['final'])
#result
    id  grade   final
0   1   3       6.0
1   2   5       4.0
2   3   3       2.0
3   2   2       4.0
4   5   1       NaN