[add-sub-mul-div]

In production what's making your application slow is extremely unlikely to be the python code. It's going to be I/O, the threading/concurrency architecture, other mistakes or inefficiency that can be cleared up without leaving the ecosystem. The question of fast vs. slow languages doesn't make a lot of sense to entertain before you have any context of the specific needs of the application or use case. On its own it's just unsophisticated vanity blog fodder.

[Intralexical]

With the obvious caveat that low-level game engine, image/video processing, numerical code etc. isn't really viable in Python. But outside of that, it's fast enough for gluing together other code that's doing the heavy lifting.

[add-sub-mul-div]

Right, if you're writing an Xbox game for example you wouldn't go with Python but if you're in the range of use cases where a language isn't fully disqualified then the pure speed of the language itself rarely needs to guide the decision.