for x in xrange(0,21):
  if x%2>0: continue
  print x,
# 0 2 4 6 8 10 12 14 16 18 20
---------------------------------------
for x in (-1,0,0,5,2,-3,4):
  if x>0: print x; break
else: print 'Nessun elemento positivo.'
# 5

for x in (-1,0,0,-5,-2,-3,-4):
  if x>0: print x; break
else: print 'Nessun elemento positivo.'
# Nessun elemento positivo.
---------------------------------------
for i in xrange(4):
  for j in xrange(5):
    print i+j,
  print
---------------------------------------
u=[[1,10],[2,10],[3,10],[4,20]]
for x,y in u: print x+y,
print
# 11 12 13 24

v=['Aa','Bb','Cc','Dd','Ee']
for x,y in v: print y+'.'+x,
print
# a.A b.B c.C d.D e.E

w=[[1,2,5],[2,3,6],[11,10,9]]
for x,y,z in w: print x*y+z,
# 7 12 119
---------------------------------------
def prodottoscalare (u,v):
  s=0
  for x,y in zip(u,v): s+=x*y
  return s

u=[1,3,4]
v=[6,2,5]

print prodottoscalare(u,v)
# 32
---------------------------------------
x=0; v=[]
while not x in v:
  v.append(x)
  x=(7*x+13)%17

for x in v: print x,
print
# 0 13 2 10 15 16 6 4 7 11 5 14 9 8 1 3

while 1:
  nome=raw_input('Come ti chiami? ')
  if nome=='': break
  print 'Ciao, %s!' %(nome)
---------------------------------------
a=[1,2,3]; b=[11,12,13]
c=[21,22,23]; d=[31,32,33]
for x in zip(a,b,c,d): print x
# Output:

(1, 11, 21, 31)
(2, 12, 22, 32)
(3, 13, 23, 33)
---------------------------------------
a=[1,2,3,4]; b=[11,12]
c=[21,22,23,24]
for x in zip(a,b,c): print x
# Output:

(1, 11, 21)
(2, 12, 22)
---------------------------------------
a=[0,1,2,3]; b=['a',7,'geo',[9,10]]
c=[11,12,13,14]
d=['A','B','C',['E','F']]
for x in zip(a,b,c,d): print x
# Output:

(0, 'a', 11, 'A')
(1, 7, 12, 'B')
(2, 'geo', 13, 'C')
(3, [9, 10], 14, ['E', 'F'])
---------------------------------------
nomi=('Verdi','Rossi','Bianchi')
stipendi=(2000,1800,2700)
for x,y in zip(nomi,stipendi):
  print x,y
# Output:

Verdi 2000
Rossi 1800
Bianchi 2700