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.
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
By default, Mono will be used on Linux and macOS, .NET Framework on Windows. For details on the loading of different runtimes, please refer to the documentation.
If .NET Core is installed in a default location or the dotnet
CLI tool is on
the PATH
, loading it instead of the default (Mono/.NET Framework) runtime
just requires setting either the environment variable
PYTHONNET_RUNTIME=coreclr
or calling pythonnet.load
explicitly:
from pythonnet import load
load("coreclr")
import clr
- 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). - Then call
PythonEngine.Initialize()
. If you plan to use Python objects from multiple threads, also callPythonEngine.BeginAllowThreads()
. - 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.
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.]
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
This project is supported by the .NET Foundation.