Python is fast for most of your needs.
Blaze it up with GPU for data science and other complex computations.
You can get free GPU for 12 hours per day on Google Colab, you can also get a dedicated 4 cores CPU for free using Azure Notebook.
And if you've gone far, you can get cheap cloud GPU and 4 cores CPU at Nimblebox.ai or Crestle.com.
Now for games, raw python might frustrate you depending on the complexity of the game.
But you can code python from Blender3d for high end games and it is fast because the Blender3d engine was built with C++, but uses python for scripting.
So you can pretty much bypass the speed issues with python for most applications.