I'm currently doing the following to create and execute a simple python calculation, using DLR:
ScriptRuntime runtime = Python.CreateRuntime();
ScriptEngine engine = runtime.GetEngine("py");
MemoryStream ms = new MemoryStream();
runtime.IO.SetOutput(ms, new StreamWriter(ms));
ScriptSource ss = engine.CreateScriptSourceFromString("print 1+1", SourceCodeKind.InteractiveCode);
CompiledCode cc = ss.Compile();
cc.Execute();
int length = (int)ms.Length;
Byte[] bytes = new Byte[length];
ms.Seek(0, SeekOrigin.Begin);
ms.Read(bytes, 0, (int)ms.Length);
string result = Encoding.GetEncoding("utf-8").GetString(bytes, 0, (int)ms.Length);
Console.WriteLine(result);
Which prints '2' to the console, but;
I want to get the result of 1 + 1 without having to print it (as that seems to be a costly operation). Anything I assign the result of cc.Execute() to is null. Is there any other way I can get the resulting variables from Execute()?
I am also trying to find a way to pass in parameters, i.e. so the result is arg1 + arg2 and have no idea how to do that; the only other overload for Execute takes ScriptScope as a parameter, and I've never used python before. Can anyone help?
[Edit] The answer to both questions: (Desco's accepted as pointed me in the right direction)
ScriptEngine py = Python.CreateEngine();
ScriptScope pys = py.CreateScope();
ScriptSource src = py.CreateScriptSourceFromString("a+b");
CompiledCode compiled = src.Compile();
pys.SetVariable("a", 1);
pys.SetVariable("b", 1);
var result = compiled.Execute(pys);
Console.WriteLine(result);
You can either evaluate expression in Python and return its result (1) or assign value to some variable in scope and later pick it (2):
var py = Python.CreateEngine();
// 1
var value = py.Execute("1+1");
Console.WriteLine(value);
// 2
var scriptScope = py.CreateScope();
py.Execute("a = 1 + 1", scriptScope);
var value2 = scriptScope.GetVariable("a");
Console.WriteLine(value2);