Trying to use pd.merge , I don't understand how to specify the collumn we want to add in an other dataframe.

Is it possible?

Below is what I would Like to do :

DF1

DF2

The output would be :

I have tried :

Output = DF1.merge(DF2, on = 'ID', how='left')

Which works but it merge all column and not only the name column.

How Can I specify 1 or several column using merge. In this example, we need to specify that we want only Name column to be added to DF1.

CodePudding user response：

Slice DF2 to only keep the key(s) and the column(s) to add:

Output = DF1.merge(DF2[['ID', 'Name']], on='ID', how='left')

output:

    index   ID  Name
0       0    1   ART
1       1   21  DRAW
2       2    7  GAME

CodePudding user response：

You can change the columns associated to your dataframes within the merge itself, for example

Output = DF1.merge(DF2[['ID','Name']], on = 'ID', how='left')

This will only take the two columns you want into the merge and because 'Name' is an additional column it will join this onto DF1