In one of the projects i want to use scripting language featuers to easily change the behaviour of my application on the runtime. I choosed Python and its .Net implementation IronPython beacuase it is a solid and popular language.
Before we can start we need :
There is also a nice Visual Studio 2010 integration tool which adds new project templates and interactive command prompt to Visual Studio IDE.
In our code we have to add assembly references :
You can find these files in the IronPython installation folder.
Create simple testing script with just one function declaration
def Simple(): print "Hello from Python Interpreter" test.py - filename
This script will print a “marvellous” Hello World style text 😀
In .Net code we have to:
1. Initialize Python Runtime
2. Load File with the script to dynamic object
3. Use dynamic [this keyword is a new addition to the .Net 4.0] object as class , referencing method in script file.
var ipy = Python.CreateRuntime(); dynamic test = ipy.UseFile("Test.py"); test.Sample();
This code will execute function Simple which is defined in the python script file.Test is a dynamic object , we dont know on the compile time what kind of object it is. The dynamic object will be defined on the runtime. Dynamic keyword is a new addition in the .Net 4.0 Framework. It is simmilar to the var keyword but , it has a different behaviour. Var is defined on the compile time [while the dynamic on the runtime] . Compilator while creating byte code gueses object from the application cntext.DLR [Dynamic Language Runtime] is a link beetwen CLR and dynamicly typed languages like Python (IronPython) or Ruby (IronRuby). It is build on top of the CLR.
Where could we use a scripting language integration ?
The game called “Civilization 4” is a great example of a architecture with core engine created in c++ and almost everything else , from the ai logic , scenarios , map generatior to the ui mechanics is created based on the python code. This architecture creates a great enviroment for end users. By using Python gamers created lot of great mods for the game.