Please, use myPyByteArray.GetBuffer() and the PyBuffer.Read method to copy from a NumPy array.

I created a feature request to make the default conversion mechanism take advantage of PyBuffer some time in the future.

Regards,

Victor

From: Jordan GUILLOT
Sent: Monday, June 27, 2022 8:19 AM
To: pythonnet@python.org
Subject: [Python.NET] [Pythonnet] Python to c# long conversion time

Hi,

I’m using Pythonnet to import proprietary python package from Windows Application.

When my python package return a large byte array in C# world, the type conversion takes lot of time.

To illustrate this long conversion time, I made a simple example:

1. A Python package with a method which return a byte array:

class MyClass:

                             @staticmethod

                             def get_bytes_from_py():

                                            array = np.arange(0, 720000, dtype=np.uint8)

                                            return bytes(array)

2. An application console to call my Python package and which convert ‘bytes’ type into ‘byte[]’ type

static void Main(string[] args)

        {

            Runtime.PythonDLL = "c:\\Python38\\python38.dll";

            PythonEngine.Initialize();

            Stopwatch st = new Stopwatch();

            st.Start();

using (Py.GIL())

            {

                dynamic myPackage = Py.Import("mypackage");

                dynamic myClass = myPackage.MyClass();

                dynamic myPyByteArray = myClass.get_bytes_from_py();

long t0 = st.ElapsedMilliseconds;

byte[] myCsharpByteArray = myPyByteArray;

long t1 = st.ElapsedMilliseconds;

                Console.WriteLine("Conversion takes {0}ms", t1-t0);

            }

            st.Stop();

        }

3. The console output:

“Conversion takes 303ms”

Is this the right way for this conversion?

Environment:

Python: v3.8.10

Pythonnet:

1. Pypi: v2.5.2
2. Nuget : 3.0.0-preview2022-06-03

Windows 10 Pro

.NET framework 4.7.2

Regards,

Jordan GUILLOT