Using Arrays with Python Ctypes

Рет қаралды 4,466

Жыл бұрын

In this Video we will discuss how to pass Arrays back and forth between our C and Python programs using the ctypes library.
C File Compilation Command:
gcc -fPIC -shared -o clibrary.so clibrary.c
Website Link:
coderslegacy.com/python/ctype...
Related Links:
Ctypes Basics: • Python ctypes Tutorial...
Ctypes Datatypes and Strings: • Python ctypes Library ...
Ctypes Pointers: • Introducing Pointers i...
Ctypes with C++: • Ctypes Library - How t...

Пікірлер: 14

@AngelLilo 5 ай бұрын

This really supported me in my code. Ty soooo much!

@dimonlol7249 3 ай бұрын

Thanks so much bro!

@coderslegacy5661 3 ай бұрын

Happy to help

@Popart-xh2fd 3 ай бұрын

At 12:09 the *arr[10]* gets deleted when goes out of function scope, so that is undefined behaviour in C!

@kcvinu Жыл бұрын

Thanks for the video.

@coderslegacy5661 Жыл бұрын

Glad you found it helpful. I recieved some positive feedback on the Ctypes videos I had made earlier, and people were requesting more videos on advanced Ctypes topics, hence I made this one on Arrays. There is another one on "Structs" and "Classes" releasing in 2-3 days, so stay tuned!

@kcvinu Жыл бұрын

@@coderslegacy5661 Great!. Eagerly waiting for the video. Currently I am writing a gui library with win32 api funs. Your videos are a great help for me.

@bbjohn83 Жыл бұрын

First off, your tutorials are great and appreciate them. Thumbs up! I am running into an issue where I need to relaunch vscode every time edit and recompile the c function. Otherwise, my python terminal keeps showing the same outputs of the function before I edited + recompiled. Once I close and reopen vscode and run my py code, it shows the correct output reflecting the changes I made to the c function. I am following your example arraySum example exactly line-by-line. Any ideas how to fix this?

@Mzkysti Жыл бұрын

Hi, thanks for the video, I was just wondering why not do so called inplace "getArray" or is this possible with ctypes?: #include #include void getArray(int* arr) { for (int i = 0; i

@undeadpresident Жыл бұрын

That will work if you make the array in Python first. Sometimes you might have the array in the C code first though.

@coderslegacy5661 Жыл бұрын

@@undeadpresident Yup, that sounds correct to me.

@undeadpresident Жыл бұрын

You can pass numpy arrays and array module arrays too.

@coderslegacy5661 Жыл бұрын

Good to know.

@undeadpresident Жыл бұрын

@@coderslegacy5661 yeah with the numpy arrays the easiest way I've found is to pass (numpyarrayname.ctypes.data) to a ctypes function with c_void_p as the argtype. The other way I've used with numpy is to import ndpointer from numpy.ctypeslib then pass the array directly into the function which has the argtype (ndpointer(ctypes.c_int)) or w/e datatype. With the array module there's a command arrayname.buffer_info() which returns the array address in it's first index which can be passed to a function with c_void_p as argtype. I was just reading through the python documentation again, and it looks like they have an entire "buffer protocol" which can be used for converting arrays from C into Python objects, but I don't understand how to use it.