Hacks

gistfile1.py

'''
Define functions inside functions, 
recompile the correct function matching the 
arg count and hand it back.
'''
from types import FunctionType


class Multi(object):
    def __init__(self, fn):
        self.fn = fn

    def is_fn(self, fn):
        if isinstance(fn, type(self.fn.__code__)):
            if fn.co_argcount == len(self.args)+len(self.kwargs.keys()):
                if all([kw in fn.co_varnames for kw in self.kwargs.keys()]):
                    return True
        return False

    def __call__(self, *args, **kwargs):
        ret, self.args, self.kwargs = self.fn, args, kwargs
        for i in self.fn.__code__.co_consts:
            if self.is_fn(i):
                ret = FunctionType(i, globals=globals())
                break
        return ret(*args,**kwargs)




@Multi
def _a(*args, **kwargs):


    def fun1(arg1):
        print("hey1")


    def fun2(arg1, arg2):
        print(arg2)

    def fun3(test, arg=None):
        raise Exception("lol")

    print("fail")

_a()                 #=> "fail"
_a(1,2)              #=> 2
_a(1, arg="Hello")   #=> Exception raised "lol"