CODEWITHSUNDEEP
pythonpandasdataframe
john doe
john doe

Reputation: 435

How do I replace a dataframe's columns values with another dataframe values by Id in Pandas

There are a lot of similar questions, I tried them all but they are not working as I want them to. Let me explain:

I have two dataframes df1 and df2. Shape of df1 is (10000,10) and shape of df2 is (6000,3) .

Sample df1: 

id      col1   col2    col3
sdfge    0       43     35
fgdge    0       34     353
dfgge   500     434     345
dsggh    43     34       345
bcbnn    23      0       86
gnncn    24      0       868
iopip    0       0       687

Sample df2

id      col1   col2  
sdfge    3453     453  
fgdge    23      345   
dsggh    44     357   
iopip    0      886

Now I want to replace col1 and col2 value in df1 by using values from df2 (join by id.

Upvotes: 0

Views: 53

Answers (1)

Space Impact
Space Impact

Reputation: 13255

Use map:

df1['col1'] = (df1['id'].map(df2.set_index('id')['col1'])
                        .fillna(df1['col1'], downcast='infer'))
df1['col2'] = (df1['id'].map(df2.set_index('id')['col2'])
                        .fillna(df1['col2'], downcast='infer'))

print(df1)
      id  col1  col2  col3
0  sdfge  3453   453    35
1  fgdge    23   345   353
2  dfgge   500   434   345
3  dsggh    44   357   345
4  bcbnn    23     0    86
5  gnncn    24     0   868
6  iopip     0   886   687

Upvotes: 1

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