mlk

class accepts_wrap(object):
    def __init__(self, func, argtypes):
        self.func = func
        self.__doc__ = func.__doc__
        self.argtypes = argtypes

    def __call__(self, *args):
        for i, (arg, cls) in enumerate(zip(args, self.argtypes)):
            if not isinstance(arg, cls):
                raise TypeError("Expected %r for argument #%d got %r" % (cls, i+1, type(arg)))
        return self.func(*args)

def accepts(*argtypes):
    return lambda func: accepts_wrap(func, argtypes)


@accepts(float, float)
def float_div(a, b):
    """
    A function that divides floats.
    Any other types of arguments will throw an exception

        >>> float_div(1.0, 2.0)
        0.5
        >>> float_div(1, 1.0)
        Traceback (most recent call last):
        ...
        TypeError: Expected <type 'float'> for argument #1 got <type 'int'>
    """
    return a / b