PYODBC--Data source name not found and no default driver specified

Do not put a space after the Driver keyword in the connection string.

This fails on Windows ...

conn_str = (
    r'DRIVER = {SQL Server};'
    r'SERVER=(local)\SQLEXPRESS;'
    r'DATABASE=myDb;'
    r'Trusted_Connection=yes;'
)
cnxn = pyodbc.connect(conn_str)

... but this works:

conn_str = (
    r'DRIVER={SQL Server};'
    r'SERVER=(local)\SQLEXPRESS;'
    r'DATABASE=myDb;'
    r'Trusted_Connection=yes;'
)
cnxn = pyodbc.connect(conn_str)

I've met same problem and fixed it changing connection string like below. Write

'DRIVER={ODBC Driver 13 for SQL Server}'

instead of

'DRIVER={SQL Server}'

I'm using Django 2.2

and got the same error while connecting to sql-server 2012. Spent lot of time to solve this issue and finally this worked.

I changed driver to

'driver': 'SQL Server Native Client 11.0'

and it worked.

Local Ms Sql database server need or {ODBC driver 17 for SQL Server} Azure Sql Database need{ODBC driver 13 for SQL SERVER}

Check installed drivers here => Installed ODBC Drivers

Format for connection to Azure Sql Database is :

import pyodbc
conn = pyodbc.connect('DRIVER={ODBC Driver 13 for SQL Server};'
                      'SERVER=tcp:nameServer.database.windows.net,1433;'
                      'DATABASE=Name database; UID=name; PWD=password;')

Format for connection to Ms SQL Databse Local:

import pyodbc
conn = pyodbc.connect('DRIVER={ODBC Driver 17 for SQL Server};'
                      'SERVER=server.name;' // example Doctor-Notebook\\MSSQLEXPRESS
                      'DATABASE=database.name; Trusted_connection = yes')