Importing external python module to test complete

Hi , 

I am working on a project with my firm and i am trying to connect to a data base via python scripts.
The problem is whenever i try this code : 

from os import sys
sys.path.insert(0,"C:\Temp\python3.6\Lib\site-packages")
import pymssql

the first time it works fine but then on the second execution i get this error 

To make it work again i have to start test complete again and also again it works fine first time and on the second execution it does the same error

can you help please its urgent !!!