I always thought of Python as being a great utility programming language. It's not really a specialist, more of a jack of all trades.
For example PHP is all about web development. Ruby is probably most well known for Rails and also widely used for web development. Python is widely used for web development, but that's not necessarily the first thing you think of for Python.
What's going to keep any programming language alive is the libraries that become so well entrenched that a competing library would have a serious uphill battle to even come close to matching functionality. Python has a lot of libraries like this for scientific tools.
I'm always skeptical to hear that a developer has moved from X programming language to Go. I wonder how many of these tales are from developers who are actually referring to what they do in their spare time rather than their day jobs. Go is still early enough that doing the sorts of things which create the most jobs is still more painful than it needs to be (and so you would probably be doing these things in a different ecosystem.) It seems that the real Go job generating stories are from start-ups which have hit some momentum, received funding and are rewriting parts of their stack in Go.
The mass job generators are still at the Rails / Django / PHP / JS levels.