def fab(max): 
  n, a, b = 0, 0, 1 
  while n < max: 
    print b 
    a, b = b, a + b 
    n = n + 1

 def fab(max): 
  L = []
  n, a, b = 0, 0, 1 
  while n < max: 
    L.append(b) 
    a, b = b, a + b 
    n = n + 1
  return L

for i in range(1000): pass
for i in xrange(1000): pass

 class Fab(object): 
  def __init__(self, max): 
    self.max = max 
    self.n, self.a, self.b = 0, 0, 1 
 
  def __iter__(self): 
    return self 
 
  def next(self): 
    if self.n < self.max: 
      r = self.b 
      self.a, self.b = self.b, self.a + self.b 
      self.n = self.n + 1 
      return r 
    raise StopIteration()

>>> for key in Fabs(5):
  print key

>>> lst = range(5)
>>> it = iter(lst)
>>> it
<listiterator object at 0x01A63110>

>>> it.next()
 
>>> it.next()
 
>>> it.next()

>>> it.next()
 
>>> it.next
<method-wrapper 'next' of listiterator object at 0x01A63110>
>>> it.next()
 
>>> it.next()
 
Traceback (most recent call last):
 File "<pyshell#27>", line 1, in <module>
  it.next()
StopIteration

lst = range(5)
it = iter(lst)
try:
  while True:
    val = it.next()
    print val
except StopIteration:
  pass

>>> a = (1, 2, 3, 4)
>>> for key in a:
  print key

# -*- coding: cp936 -*-
class Fabs(object):
  def __init__(self,max):
    self.max = max
    self.n, self.a, self.b = 0, 0, 1 #特别指出：第0项是0，第1项是第一个1.整个数列从1开始
  def __iter__(self):
    return self
  def next(self):
    if self.n < self.max:
      r = self.b
      self.a, self.b = self.b, self.a + self.b
      self.n = self.n + 1
      return r
    raise StopIteration()
 
print Fabs(5)
for key in Fabs(5):
  print key

<__main__.Fabs object at 0x01A63090>

def fab(max):
  n, a, b = 0, 0, 1
  while n < max:
    yield b
    a, b = b, a + b
    n = n = 1

>>> for n in fab(5):
  print n

>>> f = fab(3)
>>> f.next()
1
>>> f.next()
1
>>> f.next()
2
>>> f.next()
 
Traceback (most recent call last):
 File "<pyshell#62>", line 1, in <module>
  f.next()
StopIteration

>>> s = fab(5)
>>> s.next()
1
>>> s.next()
 
Traceback (most recent call last):
 File "<pyshell#66>", line 1, in <module>
  s.next()
StopIteration

 def read_file(fpath): 
  BLOCK_SIZE = 1024 
  with open(fpath, 'rb') as f: 
    while True: 
      block = f.read(BLOCK_SIZE) 
      if block: 
        yield block 
      else: 
        return