Panda remove duplicates but keep relationship

Question

How to drop duplicates but keep the relationship.

In my case I have duplicates inside Stock, but no duplicates inside Code.

import pandas as pd

df = pd.DataFrame({'Code' : ['NSPWRUTBL1','NSPWRUTBL2','NSPWRUTBL3','NSPWRUTPK1','NSPWRUTPK2','NSPWRUTPK3'],
               'Stock' : ['890353-336','890353-336','890353-336','890353-850','890353-850','890353-850']})
print(df.drop_duplicates())

Actual Output :

         Code       Stock
0  NSPWRUTBL1  890353-336
1  NSPWRUTBL2  890353-336
2  NSPWRUTBL3  890353-336
3  NSPWRUTPK1  890353-850
4  NSPWRUTPK2  890353-850
5  NSPWRUTPK3  890353-850

I'm expecting to get one instance something like :

0  NSPWRUTBL1  890353-336
3  NSPWRUTPK1  890353-850