a=[n*n for n in xrange(8)]
print a
# [0, 1, 4, 9, 16, 25, 36, 49]

a=(n*n for n in xrange(8))
print a
# <generator object at 0x596e4c>

for k in xrange(4): print a.next(),
# 0 1 4 9
---------------------------------------
def quadrati ():
  n=0
  while 1:
    yield n*n; n+=1

q=quadrati()
for k in xrange(8): print q.next(),
# 0 1 4 9 16 25 36 49
---------------------------------------
def genfatt ():
  f=1; i=2
  while 1: yield f; f*=i; i+=1

fattoriali=genfatt()

for k in xrange(8):
  print fattoriali.next(),
# 1 2 6 24 120 720 5040 40320
---------------------------------------
def quadrati (n):
  for k in xrange(n): yield k*k

q=quadrati(8)
for x in q: print x,
# 0 1 4 9 16 25 36 49
---------------------------------------
def generafib (n):
  a=0; b=1
  for k in xrange(n):
    a,b=a+b,a
    yield a

fib=generafib(9)
for x in fib: print x,
# 1 1 2 3 5 8 13 21 34
---------------------------------------
fib=generafib(9)
print list(fib)
# [1, 1, 2, 3, 5, 8, 13, 21, 34]
---------------------------------------
fib=generafib(9)
for x in fib: print x,
print list(fib)
# []

fib=generafib(9)
for k in xrange(5):
  print fib.next(),
# 1 1 2 3 5
print
print list(fib)
# [8, 13, 21, 34]
---------------------------------------
def generanumeri ():
  n=0
  while 1: yield n; n+=1

numeri=generanumeri

def schemadiprogramma ():
  while 1:
    e=evento()
    if e.azione=='fine': break
    if e.azione=='inserimento':
      n=numeri.next()
      inserisci(e.libro,n)
---------------------------------------
cos=math.cos
g=(cos(x) for x in (0.9,0.1,0.4,0.4))
print max(g)
# 0.995004165278
print list(g)
# []
---------------------------------------
def leggirighe (nome):
  f=file(nome,'r')
  while 1:
    a=f.readline()
    if not a: break
    a=a.strip()
    if a: yield a
  f.close()

righe=leggirighe('dati')
numeri=(int(x) for x in righe)
print numeri
# <generator object at 0xf7d6ec>

def somma (v):
  s=0
  for x in v: s+=x
  return s

print somma(numeri)
# 8183 (ad esempio)