Introducing Pointers in Python using the Ctypes Library

In this tutorial we will explore how we can introduce Pointers into Python using the ctypes library, as well as how to allocate and deallocate dynamic memory.
Website Link: coderslegacy.com/python/ctype...
Related Links:
Ctypes Basics: • Python ctypes Tutorial...
Ctypes Datatypes and Strings: • Python ctypes Library ...
Ctypes with C++: • Ctypes Library - How t...

[@chaxiraxi_ytb]

This video series is so underrated thank you so much

[@russianvodka666]

The feeling when it is not clear in the documentation, but the KZbin person explained everything. You're beautiful! Like!

[@seamusrohe9226]

Subbed. @CodersLegacy your videos are amazing! The concise and steady pace that you present these concepts is so easy to follow along with, you really have a knack for making these videos. Keep up the good work! I've been really struggling with ctypes (using C++) and even your videos on ctypes with C are so helpful. I can't wait for more content about C++. Do you have a discord I'd love to be able to ask you a few questions if you have t he time? There are VERY few good videos or any form of toutorials on this subject I was so happy when i found your channel.

[@MARIO-tb3tr]

Very very helpful

[@JohnWolf-ir7qg]

LP in the returned contents of the ctype C string stands for Long Pointer.

[@coderslegacy5661]

Thanks for sharing!

[@undeadpresident]

I have been using ctypes to speed up my python code. I don't see why you would think this is a bad idea. I can't run cython or numba on my machine. Right now trying to figure out how to send a pointer of a pygame surface to ctypes so I can manually alter the data in C because python is slow af. I appreciate the vids though, saves me time trying to figure out what the documentation is saying when I can see it in action.

[@coderslegacy5661]

It's certainly not a bad idea. It's an obvious performance benefit, which I even made a video on recently. But if it comes down to a situation between Cython and Ctypes where both can be used, and your only concern is speed, then Cython would be a better choice. There are so many other factors too. Depends on the situation at hand and what you feel comfortable doing. Glad to see that my videos have been helping you by the way. Thanks for the feedback.

[@undeadpresident]

@@coderslegacy5661 Yeah I wanted to use cython but I have an older machine and was having compatibility issues with it (and numba) and wanted to learn C better anyway so I went with ctypes. I figured out how to get the surface data from pygame into C now. :) I used the pygame surfarray.pixels3d() function to get an array then passed it as a pointer to ctypes. The pointer created in python was 2 elements in from the actual start of the data so a negative index had to be used, and the real data was organized in Y,X instead of X,Y, and with the format RABG rather than RGB. ;)

[@thetimeee1312]

Straight forward tutorial but you should've explained in more detail why one wants to use pointers in the first place. We don't need to use neither pointers nor the heap to achieve whatever we want. We need to use pointers to achieve it as performant as possible by passing references instead of copying the whole memory of whatever we are trying to pass to methods etc.

[@kcvinu]

Hi thanks for this video. I have a question. How do we pass a python class instance to a C function and get it back from another C function ? For example, Let's say I have a Window class in python. After creating the window, I just need to pass the self pointer to "SetWindowLongPtr" function. Then I can get my Window object inside the WndProc function, with the help of GetWindowLongPtr function. How to do this ?

[@undeadpresident]

the next video in his series covers passing classes to C code as structs

[@kcvinu]

@@undeadpresident Great, thank you:)

[@undeadpresident]

@@kcvinu np

[@ravigandhi1698]

How do we use enum in ctypes

[@ReinventedWeb]

What sorcery is this? Pointers in python?? Witch.

[@coderslegacy5661]

It's Dark Magic.