Concatenating two DataFrames but only for common values in Python

Question

I have 2 dataframes like this:

name    code phone_number 
Joe     BX13    03453
Bill    C308    321356
Donald  H314    34532
Mike    J4D6    2134

code vehicle
C308 Mercedes
H314 BMW

I would like to concatenate them but only for common values in a specific column so it would look like this:

name    code vehicle
Bill    C308 Mercedes
Donald  H314   BMW

df3=pd.concat([df1, df2])

looks promising but I don't know to specify that I only want the common values. What arguments should I put in the parenthesis?

Answer 1

You can use df.merge

Setting up your data

import pandas as pd
import io
t = '''
name,code,phone_number
Joe,BX13,3453
Bill,C308,321356
Donald,H314,34532
Mike,J4D6,2134'''
df1 = pd.read_csv(io.StringIO(t))

t = '''
code,vehicle
C308,Mercedes
H314,BMW'''
df2 = pd.read_csv(io.StringIO(t))

Now you can merge the two dataframes with selected columns

df1[['name','code']].merge(df2, on='code', how='inner')

Out:

     name  code   vehicle
0    Bill  C308  Mercedes
1  Donald  H314       BMW