>>> import itertools
>>> from selelem import selelem

>>> sel = itertools.cycle([True, False])
>>> nombres = itertools.count(10)
>>> exemple = selelem(nombres, sel)
>>> for i in range(10):
...     print(next(exemple), end='·')
... 
10·12·14·16·18·20·22·24·26·28·

--ini-enunciat
>>> seleccio = [True, False, False, True, True, False, True]
>>> nombres  = [   0,     1,     2,    3,    4,     5,    6,    7,    8,   9]
>>> # resultat:    0                   3     4            6
>>> exemple = selelem(nombres, seleccio)
>>> for n in exemple:
...     print(n, end='·')
... 
0·3·4·6·
>>> sel = itertools.cycle([True, False, False, True])
>>> nombres = itertools.count(10)
>>> exemple = selelem(nombres, sel)
>>> for i in range(10):
...     print(next(exemple), end='·')
... 
10·13·14·17·18·21·22·25·26·29·

>>> sel= (True, False, False, False, False, False, False, True )
>>> for n in selelem(range(100), sel):
...     print(repr(n), end='·')
0·7·
>>> sel= (n % 7 == 0 for n in range(100))
>>> for c in selelem('Avinguda Diagonal, 647 08029 Barcelona', sel):
...     print(repr(c), end='·')
'A'·'a'·'n'·'7'·' '·'o'·

--fi-enunciat