SQLAlchemy no password supplied error
You probably just need to remove "localhost" from your connection string:
'postgresql:///db_name'That tells psycopg2 to use Unix-domain sockets. Your default configuration will use "ident" so you'll be connecting as the user that runs the script. In the default configuration, "md5" only applies to TCP connections.
URL pattern should be:
postgresql://user:password@localhost:5432/database_namepip install psycopg2
the user should be postgres or any other user you have created and intend to use
similarly for mySql it would be:
mysql://user:pass@localhost:3306/database_namepip install mysql-python
On your Mac, PostgreSQL was set up for trust or peer authentication for connections from localhost.
On your Ubuntu box it's set up for md5 authentication for connections from localhost.
You'll want to configure a password, or change the authentication mode. See pg_hba.conf, and the Ubuntu guide for PostgreSQL (there's a section about this error).