pythonnet

Python for .NET is a package that gives Python programmers nearly seamless integration with the .NET Common Language Runtime (CLR) and provides a powerful application scripting tool for .NET developers. It allows Python code to interact with the CLR, and may also be used to embed Python into a .NET application.

Calling .NET code from Python

Python for .NET allows CLR namespaces to be treated essentially as Python packages.

    import clr
    from System import String
    from System.Collections import *

To load an assembly, use the "AddReference" function in the "clr" module:

    import clr
    clr.AddReference("System.Windows.Forms")
    from System.Windows.Forms import Form

Embedding Python in .NET

All calls to python should be inside a "using (Py.GIL()) {/* Your code here */}" block.
Import python modules using dynamic mod = Py.Import("mod"), then you can call functions as normal, eg mod.func(args).
Use mod.func(args, Py.kw("keywordargname", keywordargvalue)) to apply keyword arguments.
All python objects should be declared as 'dynamic' type.
Mathematical operations involving python and literal/managed types must have the python object first, eg np.pi2 works, 2np.pi doesn't

EG:

static void Main(string[] args)
{
  using (Py.GIL()) {
    dynamic np = Py.Import("numpy");
    dynamic sin = np.sin;
    Console.WriteLine(np.cos(np.pi*2));
    Console.WriteLine(sin(5));
    double c = np.cos(5) + sin(5);
    Console.WriteLine(c);
    dynamic a = np.array(new List<float> { 1, 2, 3 });
    dynamic b = np.array(new List<float> { 6, 5, 4 }, Py.kw("dtype", np.int32));
    Console.WriteLine(a.dtype);
    Console.WriteLine(b.dtype);
    Console.WriteLine(a * b);
    Console.ReadKey();
  }
}

outputs:

1.0  
-0.958924274663
-0.6752620892
float64
int32
[  6.  10.  12.]