Another python thing I forget: dictionary construction

I am always forgetting how to do dictionary construction. Here is a piece of code I restructured for a friend. Notice that the dictionary is created from a sequence of tuples. (Slightly modified from the original for better pretty-printing.)

def slug_to_lower(fn):
    """
    Decorator to lowercase string arguments to a function.
    """
    import string
    def is_string(x):
        return isinstance(x, str) or isinstance(x, unicode)
    def trans(x):
        return (x if not is_string(x) else string.lower(x))
    def wrapped(*args, **kwargs):
        neo_args = [trans(x) for x in args]
        tuple_list = [(k,trans(v)) for k,v in kwargs.items()]
        neo_kwargs = dict(tuple_list)
        return fn(*neo_args, **neo_kwargs)
    return wrapped