sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not connect to server: Connection refused site:stackoverflow.com code example
Example: psycopg2.OperationalError: could not connect to server: Connection refused Is the server running on host "127.0.0.1" and accepting TCP/IP connections on port 5432?
# to over ride this error you should up and run server
service postgresql start