[Python.NET] [Pythonnet] Python to c# long conversion time

27 Jun 2022

      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)

  1.  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();
        }

  1.  The console output:

"Conversion takes 303ms"

Is this the right way for this conversion?

Environment:
Python: v3.8.10
Pythonnet:

  *   Pypi: v2.5.2
  *   Nuget : 3.0.0-preview2022-06-03
Windows 10 Pro
.NET framework 4.7.2

Regards,
Jordan GUILLOT