Question

First of all I am new to python and a bit rusty on .NET so bear with me if this sounds
too obvious.
Assuming the following python classes;

class foo1(object):
      def bar1(self):
         print "bar1 called."
      def bar2(self):
         print "bar2 called."
class foo2 ..... same as above

I want to store the class methods somewhere and want to invoke them on an object of my own choosing.This is what I came up with.

ObjectOperations ops = engine.Operations;
IList<string> members = ops.GetMemberNames(scope);
foreach(string member in members)
{
   if(member.StartsWith("foo"))
      {
         dynamic klass= scope.GetVariable(member);
         dynamic instance= klass();
         //for brevity I am skipping the enumeration of
         //function names here.
         dynamic func = ops.GetMember(instance, "bar1");//and store it somewhere
         Action act = ops.ConvertTo<Action>(func); //This part is not really necessary

       }
}

What I want to do is invoking the func(of type IronPython.Runtime.Method) on a instance I create sometime later. From what I glean from IronPython source that the instance is set in stone when it’s created and I cannot change it.Is there a way accomplish this? I am also not sure in what context(scope??) to run the function or I shouldn’t worry about it all.

ObjectOperations do have a method called MemberInvoke that takes a object and member name but I’d rather prefer MethodInfo.Invoke type of invocation both for style and performance considerations.

Any pointers would be greatly appreciated.

P.S. I am using IronPython 2.7 and .Net4.0 by the way..

Answer 1

Yes, this is actually very easy. In Python methods can either be invoked as bound methods such as:

x = C().f  # produces a bound method
x() # invokes the bound method

Which is the same as:

C().f()

Or they can be invoked with an explicit self parameter:

C.f(C())

This works the same way from the hosting APIs, so all you need to do is something like:

dynamic klass = scope.GetVariable(member);
dynamic func = ops.GetMember(klass, "bar1");

// and then later:
func(inst);