I am developing a program using C#, but I just figured out that what I am going to program is very very difficult in C# yet easy in Python. So what I want to do is make a .PYD file and use it in C# program, but I don't know how. I've been searching about it but I couldn't find anything. 
So these are my questions: How do I use .PYD file in C#? I know that .PYD files are similar to .DLL files, so are .PYD files still usable in computers that have no Python installed?
A .pyd file IS a DLL but with function init*() where * is the name of your .pyd file. For example, spam.pyd has a function named initspam(). They are not just similar, but the same! They are usable on PCs without Python.

Do not forget: builtins will NOT be available. Search for them in C, add them as an extern in your Cython code and compile!
Using .PYD file in C#?