>If your packaging systems supports version selection/locking, then use your packaging system right. That's exactly what the article is recommending in point 2

>If your packaging systems supports version selection/locking, then use your packaging system right. That's exactly what the article is recommending in point 2. The original Dockerfile author was using pip in a way that's only intended for in development. Having a requirements.txt file is the correct way to use pip when distributing a project.