[daeken]

I'm going to hell for this, but here goes. A couple years back I wrote a library called Transformana ( https://github.com/daeken/Transformana ) which allows you to manipulate ASTs via 'macros' in decorators. I apologize from the bottom of my heart to anyone who ends up maintaining code that utilizes this, but have fun.

https://github.com/daeken/Transformana/blob/master/test.py shows off various features if you're interested.

Edit: Here's the output from running the test, in case you want to see the AST format.

    Hello world!
    Yep, working.
    Don't know.
    ['function',
     None,
     'test2',
     (),
     (),
     0,
     None,
     ['stmt', [['printnl', [['const', 'Hello from test2']], None]]]]
    Hello from test2
    ['function', None, 'test3', (), (), 0, None, ['stmt', [['printnl', [['const', 'This should never be callable']], None]]]]

[softbuilder]

Fellow hell-bound soul here. I didn't go nearly as far as you did. I decided it would be fun to have guards in Python and decorators were just the tool. I sketched this out as part of a talk at Open Source Bridge a few years back:

https://github.com/built/Jane-Kelly/blob/master/guard.py

It'll let you redefine functions with different guard parameters. (@when("x=5"), @when("x>20"), etc.) Like you, I would also shudder to see this in production. But it was fun and shows off some of what's possible.