At this point, Python is probably the second most used language for system programming (after C), one of the top 4 in web development (no idea on their ordering), around the top for other network protocols (I'd guess 3rd), the top language for data science, on the top 5 of scientific computing, on the top 5 for embedded computing (what sounds completely crazy, but there are few languages there), on the top 4 for game creation (probably 4th), the top one for electronics CAD and among the top for other kinds of CAD, the top one for GIS...

I can't think of other niches right now, but whatever one you think, it's probably on the top 5 there.