Update one column of one csv based on column from another in Python

I have two csv s like below :-

Master.csv

Column1	Column2	Column3	Column4
First	1001	Test1	1003
Second	1002	Test2	1004

Reference.csv

Code	Value
1001	Val1
1002	Val2
1003	Val3
1004	Val4

As can be seen the Column2 and Column4 of Master.csv values are present in the same column Code of Reference.csv and I want to join the two csv to populate like below :-

Column1	Column2	Column3	Column4
First	Val1	Test1	Val3
Second	Val2	Test2	Val4

Please let me know it can be achieved through Python ..

I tried to join to csvs but unable to get the expected outputs.

Solution

Create DataFrames first by read_csv and use DataFrame.replace:

df1 = pd.read_csv('Master.csv')
df2 = pd.read_csv('Reference.csv', index_col=['Code'])

out = df1.replace(df2['Value'])
print (out)
  Column1 Column2 Column3 Column4
0   First    Val1   Test1    Val3
1  Second    Val2   Test2    Val4

If need write to csv:

out.to_csv('output.csv', index=False)

If need replace only columns from list:

df1 = pd.read_csv('Master.csv')
df2 = pd.read_csv('Reference.csv', index_col=['Code'])

cols = ['Column2', 'Column4']
df1[cols] = df1[cols].replace(df2['Value'])

df1.to_csv('output.csv', index=False)