Python might be the most popular programming language in the world, but that doesn't mean it can be used everywhere. I've listed some fields where using Python is not recommended.
This is because Python is very, very slow compared to something like C/C++, just because it is an interpreted language. These languages are processed at runtime. Every line is read, analyzed, and executed. This makes the interpreted code run 5 - 10 times slower than compiled code. Even JIT-compiled languages like Java can beat Python in terms of speed. This isn't to say that you can't write device drivers with Python and then use C or assembly language layer to communicate with hardware, but this route isn't generally used.
While it serves as an excellent server-side language, Python is rarely seen on the client-side. Besides that, it is rarely ever used to develop mobile applications. Neither Android nor iOS support Python as an official programming language.
It is still possible to develop mobile applications in Python using Kivy, but it requires more time and effort on the part of the developer to deliver a rich user experience. That is why Kotlin and Swift are some of the preferred languages when it comes to mobile app development. And Java is commonly used for banking web applications due to its particular strength in security functionality and environment. Java includes access to certain security features such as cryptography, and advanced authentication and access control that keep your web application secure.
PyGame or Tkinter libraries are a good choice for beginners learning how to make simple games. But, the performance of Python isn't good enough for the resource-intensive parts of the game engine for higher-end games. Therefore for more resource-intensive games, developers consider the industry standard which is C# with Unity or C++ with Unreal. And most people getting into game development are looking for a robust platform that offers plenty of scalabilities. Unity and Unreal offer exactly that, and you need to know C# or C++ to use them. However, Python is used as a scripting language in some game engines.
Python needs more resource overhead and is also a lot slower. Especially in embedded devices, you can't have luxury like an automatic garbage collector. Once a program is written in C/C++, it can be converted into bytecode/instructions for a particular embedded platform and uploaded onto it, but you can't do that in Python as it is an interpreted language. C can also utilize the hardware to its maximum by multiprocessing and multithreading APIs provided by POSIX, but Python can't work like that because it has GIL.
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