def fatt (n):
  return iftern(n==0,1,n and n*fatt(n-1))
---------------------------------------
def positivo (x): return x>0 or False

def segno (x):
  return x>0 and 1 or x<0 and -1 or 0

def bin (n,k): # Numeri binomiali.
  return k==0 and 1 or n<k and 0
    or (float(n)/k)*bin(n-1,k-1)

def prod (a,b): # a(a+1) ... b
  return iftern(a>b,1,a<=b and
    iftern(a==b,a,a<b and b*prod(a,b-1)))

for b in xrange(2,7): print prod(3,b),
# 1 3 12 60 360
---------------------------------------
def iftern (A,x,y): # Non corretto!
  return A and x or y

def iftern (A,x,y):
  return (A and [x] or [y])[0]
---------------------------------------
def segno (x):
  if x>0: return 1
  elif x==0: return 0
  else: return -1
---------------------------------------
operazioni = {'Roma' : 'print "Lazio"',
  'Ferrara' : 'print "Romagna"',
  'Cremona' : 'x=5; print x*x'}
for x in ['Roma','Ferrara','Cremona']:
  exec(operazioni[x])
---------------------------------------
print 10**math.log10(17)
# 17.0
---------------------------------------
def pari (x): return x%2==0

v=xrange(1,21)
print filter(pari,v)
# [2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
---------------------------------------
v=['Roma','Ferrara','Bologna','Pisa']
print filter(lambda x: len(x)>4,v)
# ['Ferrara', 'Bologna']
---------------------------------------
imp = [['Rossi',2000],['Verdi',3000],
  ['Gentili',1800],['Bianchi',3400],
  ['Tosi',1600],['Neri',2800]]
imp3000=filter(lambda x: x[1]>=3000,imp)
for x in imp3000: print x[0],
# Verdi Bianchi
---------------------------------------
def Eratostene (n):
  v=range(2,n+1); u=[]
  r=math.sqrt(n); p=2
  while p<=r:
    p=v[0]; u.append(p)
    v=filter(lambda x: x%p>0,v)
  return u+v

v=Eratostene(100); m=len(v)
for i in xrange(0,m):
  if i%8==0: print
  print v[i],

# 2 3 5 7 11 13 17 19 23 29
# 31 37 41 43 47 53 59 61 67 71
# 73 79 83 89 97