CODEWITHSUNDEEP
pythonpandasdataframe
Ramon
Ramon

Reputation: 538

Simple lookup using two dataframes in Python

I am working with pandas and my intention is to bring data from one table to other. Suppose I have two dataframes named df1 and df2:

df1 is like that:

Name    Age    Height
Marcus  18     170
Dan     21     172
Phill   30     165
Paty    24     160
Linda   25     158

df2 is like that:

Name    Score1    Score2     Score3
Dan          A         C          C
Paty         B         A          B
Marcus       C         D          B
Zoe          A         A          B

I would like to find a way to pick the ages of the guys in df1 and bring it to df2, resulting in a table like that:

Name    Score1    Score2     Score3    Age
Dan          A         C          C    21
Paty         B         A          B    24
Marcus       C         D          B    18
Zoe          A         A          B    NaN

In Excel we use VLOOKUP function in df2 to df1. But I could not find something similar in Python.

Upvotes: 2

Views: 5696

Answers (1)

Vaishali
Vaishali

Reputation: 38415

You can use map or merge, map would be faster

Option 1: Using map

df2['Age'] = df2['Name'].map(df1.set_index('Name')['Age'])

Option 2: Using merge

df2.merge(df1[['Name', 'Age']], 'left')

Either way you get

    Name    Score1  Score2  Score3  Age
0   Dan     A       C       C       21.0
1   Paty    B       A       B       24.0
2   Marcus  C       D       B       18.0
3   Zoe     A       A       B       NaN

Upvotes: 8

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