Embedding IronPython 2 in C# - What is the replacement for DefaultModule.Globals?

Question

I'm trying to convert some IronPython 1 code:

var ptype = this.engine.DefaultModule.Globals[ironPythonClassName];

I have a script that declares a class. I use a Python engine to execute the script.

How, in IronPython 2 do I get the names of the variables (including the class)?

Answer 1

You have to execute the file in a Scope:

ScriptScope scope = engine.CreateScope();
CompiledCode code = engine.CreateScriptSourceFromFile(fullPath).Compile();
code.Execute(scope);

From the scope you can call GetVariable or GetVariable to get the variable value:

object c = scope.GetVariable(ironPythonClassName)
// or
int i = scope.GetVariable<int>(otherVar);

As far as I know, the DefaultModule is completely gone in IronPython 2.x.

For simplicity, there are also convenience methods on ScriptEngine:

ScriptScope scope = engine.ExecuteFile(fullPath);
names = scope.GetVariableNames()

This is easier for one-off script usage, but using the compiled code directly is better (faster) if you're repeatedly executing the same script.

Answer 2

There is no need to create a new scope since the CompiledCode instance seems to be created with one.

ScriptEngine engine = Python.CreateEngine();
ScriptSource source = engine.CreateScriptSourceFromFile(fileName);
CompiledCode code = source.Compile();
ScriptScope scope = code.DefaultScope;
code.Execute();
var names = scope.GetVariableNames();

---

rant on

The scripting classes above are a bit of a nightmare - too much duplication of functionality and strange linkage between instances.

Why didn't MS use the well-known pattern of "an engine executes code compiled from a source, in a scope"?

So the model might be:

• compile source to produce code (Compiler class)
• provide or create a scope (Scope class)
• bind code and scope and feed them to the engine to execute (Engine Class)

rant off