Please explain when you need to write a python module in pure C, instead of using ctypes?

Question

Python

The question is related to a misunderstanding when, instead of using ctypes, you need to sit down and write in pure C?

PS:
The reason for the performance of the product is not taken into account, it is so obvious. What other reason is there besides it?

Answer 1

Yes, it was about ctypes that the question asked.
I am well aware of the availability of functions on Py_*.
I'll try in other words. When we need to use something that is not available in python. For example, a large library code written in C ++ by the company where we work, we can do this in two ways:
1) Write a pure module using the C programming language
2) Write a dll, where the functions will be either cdecl or stdcall, and then write a Python module using the ctypes module
As a rule, the second option wins in terms of code readability, while not losing much in performance over the first. Let's say I have not seen a case where the code written according to the first option would be better than written according to the second.
So the question arises: Give an example of a situation where the second method is either not possible or too difficult and therefore the first one must be used.
I hope the question is clearer now.
PS:
There is no reason to minus! If you don't understand a question, ask for clarification. Otherwise, such behavior puts you on the level of a jerk. We all may not know something and this is quite natural, for this there is an opportunity to communicate with other specialists.