IMO having some Node.js experience and React experience are very helpful to get hired into any position that is remotely near the web these days. I have seen several of my clients introduce Node.js and of course everyone is introducing SPAs in some form or another, mostly React. Mozilla is even integrating React into Firefox's UI.
I am personally skeptical of these trends, but my skepticism doesn't change the shift of the industry. My advice would be to get some Node and React experience under your belt so that you can at least discuss it intelligently, and it shouldn't be too much of an impediment moving forward.
Python is in a tough spot for growth, IMO. The new generation of languages have internalized much of what made Python great, while leaving behind a lot of the inadequacies and cruft attached to CPython.
Like you, I will always have a soft spot for Python, but it's getting increasingly difficult to continue to see it as the default choice for new projects (outside of a few specific niches).
Bolting React onto an existing codebase is probably best because it is more similar to what you'd see in the real world. Most people don't start a React/Node thing at the same time; they'll start integrating React into their frontend early because they can get little React-compatible widgets plugged in more easily than they can introduce backend changes like finding opportunities for Node.
React and Node are not really related other than they're both JavaScript-based, so the skills aren't really co-dependent. Node is used to execute JavaScript locally (in build tools like Webpack, for example), but beyond a small amount of local scripting for builds, they don't really touch (afaik; I have not yet completed a major project with either of them, just used them here and there).
I am personally skeptical of these trends, but my skepticism doesn't change the shift of the industry. My advice would be to get some Node and React experience under your belt so that you can at least discuss it intelligently, and it shouldn't be too much of an impediment moving forward.
Python is in a tough spot for growth, IMO. The new generation of languages have internalized much of what made Python great, while leaving behind a lot of the inadequacies and cruft attached to CPython.
Like you, I will always have a soft spot for Python, but it's getting increasingly difficult to continue to see it as the default choice for new projects (outside of a few specific niches).