pythonnet - Python.NET
Python.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.
Note
The master branch of this repository tracks the ongoing development of version 3.0. Backports of patches to 2.5 are tracked in the backports-2.5 branch.
Calling .NET code from Python
Python.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
- You must set
Runtime.PythonDLL
property orPYTHONNET_PYDLL
environment variable starting with version 3.0, otherwise you will receiveBadPythonDllException
(internal, derived fromMissingMethodException
) upon callingInitialize
. Typical values arepython38.dll
(Windows),libpython3.8.dylib
(Mac),libpython3.8.so
(most other Unix-like operating systems). - 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, egmod.func(args)
. - Use
mod.func(args, Py.kw("keywordargname", keywordargvalue))
ormod.func(args, 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.pi * 2
works,2 * np.pi
doesn't.
Example
static void Main(string[] args)
{
PythonEngine.Initialize();
using (Py.GIL())
{
dynamic np = Py.Import("numpy");
Console.WriteLine(np.cos(np.pi * 2));
dynamic sin = np.sin;
Console.WriteLine(sin(5));
double c = (double)(np.cos(5) + sin(5));
Console.WriteLine(c);
dynamic a = np.array(new List<float> { 1, 2, 3 });
Console.WriteLine(a.dtype);
dynamic b = np.array(new List<float> { 6, 5, 4 }, dtype: np.int32);
Console.WriteLine(b.dtype);
Console.WriteLine(a * b);
Console.ReadKey();
}
}
Output:
1.0
-0.958924274663
-0.6752620892
float64
int32
[ 6. 10. 12.]
Resources
Information on installation, FAQ, troubleshooting, debugging, and projects using pythonnet can be found in the Wiki:
https://github.com/pythonnet/pythonnet/wiki
- Mailing list
- https://mail.python.org/mailman/listinfo/pythondotnet
- Chat
- https://gitter.im/pythonnet/pythonnet
.NET Foundation
This project is supported by the .NET Foundation.