MongoDB URI with multiple nodes (host:port separated by a comma) raises `invalid literal for int()` error

[kierandarcy]

A MongoDB URI can specify multiple, comma separated host:port URL parts like this:

mongodb://username:password@host1:123,host2:456/database

A URL in this form will result in an error:

ValueError: invalid literal for int() with base 10

I have a solution which uses pymongo.uri_parser.parse_uri (if installed) to parse the the MongoDB URL, selecting the first node (or, host:port) to extract the port, hostname and database.