I would suggest to deprecate one-element tuple construction with colon at the end, because this looks ugly, is not self-evident for other people reading code, looks like some type of trickery.

It would prefer tutorial (http://docs.python.org/dev/3.0/tutorial/datastructures.html#tuples-and-sequences) to use instead of

>>> ('hello',)
('hello',)

this syntax:

>>> tuple(['hello'])
('hello',)

.

PS.

Funcitons set(), tuple(), list() and dict() are good!

Syntax

myset = {'a', 'b'}

is absolutely perfect too!