Don't get me wrong, there's a huge number of packages available and a lot of them are really quality and I have used the language a lot, but good gosh is the packaging a deployment a fucking disaster.

Environments are a 3rd party bolt on, that relies on hacking around with environment variables. There's no distinction between dev dependencies and actual, application dependencies. The packaging/deployment tool has gone through a bunch of different formats/styles and when it comes to deploying your code, you have nothing better than writing a bash script that automates your environment creation, activation and running of the packaging tool (you then just hope that Pip doesn't fail on some bizarre edge).