How do I connect to SQL Server via sqlalchemy using Windows Authentication?

In order to use Windows Authentication with sqlalchemy and mssql, the following connection string is required:

ODBC Driver:

engine = sqlalchemy.create_engine('mssql://*server_name*/*database_name*?trusted_connection=yes')

SQL Express Instance:

engine = sqlalchemy.create_engine('mssql://*server_name*\\SQLEXPRESS/*database_name*?trusted_connection=yes') 

If you're using a trusted connection/AD and not using username/password, or otherwise see the following:

SAWarning: No driver name specified; this is expected by PyODBC when using >DSN-less connections "No driver name specified; "

Then this method should work:

from sqlalchemy import create_engine

server = <your_server_name>

database = <your_database_name>

engine = create_engine('mssql+pyodbc://' + server + '/' + database + '?trusted_connection=yes&driver=ODBC+Driver+13+for+SQL+Server')