Accessing consecutive items when using a generator

Question

Lets say I have a tuple generator, which I simulate as follows:

g = (x for x in (1,2,3,97,98,99))

For this specific generator, I wish to write a function to output the following:

(1,2,3)
(2,3,97)
(3,97,98)
(97,98,99)
(98,99)
(99)

So I'm iterating over three consecutive items at a time and printing them, except when I approach the end.

Should the first line in my function be:

t = tuple(g)

In other words, is it best to work on a tuple directly or might it be beneficial to work with a generator. If it is possible to approach this problem using both methods, please state the benefits and disadvantages for both approaches. Also, if it might be wise to use the generator approach, how might such a solution look?

Here's what I currently do:

def f(data, l):
    t = tuple(data)
    for j in range(len(t)):
        print(t[j:j+l])

data = (x for x in (1,2,3,4,5))
f(data,3)

UPDATE:

Note that I've updated my function to take a second argument specifying the length of the window.

Answer 1

A specific example for returning three items could read

def yield3(gen):
    b, c = gen.next(), gen.next()
    try:
        while True:
            a, b, c = b, c, gen.next()
            yield (a, b, c)
    except StopIteration:
        yield (b, c)
        yield (c,)


g = (x for x in (1,2,3,97,98,99))
for l in yield3(g):
    print l