Imho, which language to choose depends highly on your use-case. Both, JavaScript and Python are in high demand and evolve constantly. I wouldn't dare to put one above the other without knowing the exact problem you have.
Just to name an example, Python is classically used a lot in a scientific context, however more and more people use it for automation scripts, PoCs or even for the back-end of servers.
JavaScript classically is the language of the web. It is very IO-oriented and event-driven, which is great for a UI context and also servers which do not have to do computation-heavy tasks. Even then, you can find it on more and more devices, and there are a lot of initiatives to JS-everywhere.
At the end of the day, it is also important how proficient you and your team are in one of the languages. If you have to get a job done, then you should prefer the language you are best able to work with. Stakeholders don't care a whole lot about what's under the hood, after all.
If you want to know which one to learn, then let me ask you this: are you more interested in web-dev or in application dev? If you lean more towards the web, then you should go JavaScript. The browser cannot execute anything besides JS, so you don't have a choice, and thanks to NodeJS, using JS on the server side is a breeze. TypeScript should also be considered, because typing can eliminate a lot of errors at dev-time and build-time and communicate contracts in your code more clearly. However, if you prefer writing programs for your computer (especially IO ones), I'd say Python has an edge over JS, because it has a load of libraries to get the wildest jobs done. Also, it has lots of bindings to binary libraries, which might not be the case for JS.