Python for .Net: Running an embedded interpreter

Question

I'm trying to use Python3.2 using the Python.Net version found at: https://github.com/renshawbay/pythonnet

I'm using the following simple test program:

using System;
using System.IO;
using Python.Runtime;

namespace TestPythonNet
{
    class Program
    {
        static void Main(string[] args)
        {
            string binDir = Path.GetDirectoryName(System.Reflection.Assembly.GetAssembly(typeof(Program)).Location);
            string pyHome = @"D:\src\scratch\TestPythonNet\TestPythonNet\PythonRuntime";
            PythonEngine.PythonHome = @"D:\src\scratch\TestPythonNet\TestPythonNet\PythonRuntime";
            PythonEngine.ProgramName = "PythonRuntime";
            Environment.SetEnvironmentVariable("PYTHONPATH",
                Path.GetFullPath(Path.Combine(pyHome, "DLLs")) + ";" +
                Path.GetFullPath(Path.Combine(pyHome, "Lib")) + ";" +
                Path.GetFullPath(Path.Combine(pyHome, "Lib", "site-packages")) + ";" +
                binDir
                );
            Environment.SetEnvironmentVariable("PYTHONVERBOSE", "1");
            PythonEngine.Initialize();
            PythonEngine.ImportModule("clr");
            using (Py.GIL())
            {
                PythonEngine.RunSimpleString(
                    "import clr; " +
                   "a = clr.AddReference('System'); " +
                    "print(a.Location);" +
                    "from System import Environment;" +
                    "print(Environment.MachineName);");
            }
        }
    }
}

“D:\\src\\scratch\\TestPythonNet\\TestPythonNet\\PythonRuntime” is a folder where I've copied the DLLs and Lib folder from a python 3.2 x86 distribution.

When I run it from Visual Studio it works fine (I guess it may be related to the fact that I'm using python tools for Visual Studio).

But when I run it from the console, it fails with the output:

Traceback (most recent call last):
  File "D:\src\scratch\TestPythonNet\TestPythonNet\PythonRuntime\Lib\site.py", line 481, in execsitecustomize
    import sitecustomize
UnicodeEncodeError: 'mbcs' codec can't encode characters in position 0--1: invalid character
Traceback (most recent call last):
  File "D:\src\scratch\TestPythonNet\TestPythonNet\PythonRuntime\Lib\site.py", line 497, in execusercustomize
    import usercustomize
UnicodeEncodeError: 'mbcs' codec can't encode characters in position 0--1: invalid character
C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System\v4.0_4.0.0.0__b77a5c561934e089\System.dll
Traceback (most recent call last):
  File "<string>", line 1, in <module>
UnicodeEncodeError: 'mbcs' codec can't encode characters in position 0--1: invalid character

The “print(a.Location);" works but not the “from System import Environment” . There are also all these errors about mbcs.

Any idea on what I'm doing wrong?

Answer 1

VS has Python folder in path, outside Vs there are not environment vars that can help. The point is that you must have Python in PATH. To get in deep, see this: https://github.com/pythonnet/pythonnet/issues/1301