I had been working with pyodbcfor database connection in windows envirnment and it is working fine but now I want to switch to pymssql so that it is easier to be deployed to Linux machine as well. But I am getting this error:

(20009, b'DB-Lib error message 20009, severity 9:\nUnable to connect: Adaptive Server is unavailable or does not exist (localhost:1433)\nNet-Lib error during Unknown error (10060)\n')

My connection code for using both pyodbc and pymssql is:

    import pyodbc
    import pymssql

    def connectODSDB_1():
        conn_str = (
            r"Driver={SQL Server};"
            r"Server=(local);"
            r"Database=populatedSandbox;"
            r"Trusted_Connection=yes;"
        )
        return pyodbc.connect(conn_str)

    def connectODSDB_2():
        server = '(local)'
        database = 'populatedSandbox'
        conn = pymssql.connect(server=server, database=database)
        return conn


What could be the problem? And solution?
Well after browsing internet for a while, it seems pymssql needs TCP/IP be enabled for communication. 

Open Sql Server Configuration Manager
Expand SQL Server Network Configuration
Click on Protocols for instance_name
Enable TCP/IP
Database connection failed for local MSSQL server with pymssql