>>> f=open('hello.py')
>>> f.readline()
'#!/usr/bin/python2.5\n'
>>> f.readline()
'print "hello.word!"\n'
>>> f.readline()
'\n'
>>> f.readline()
''
 
>>> for i in open('hello.py'):
...       print(i)
... 
#!/usr/bin/python2.5
print "hello.word!"

>>> for i in open('hello.py').readlines():
...     print i
... 
#!/usr/bin/python2.5
print "hello.word!"

>>> for i in range(5):
...    print(i)
... 

>>> L=[0,1,2,3,4]
>>> I=iter(L)
>>> I.next()
0
>>> I.next()
1
>>> I.next()
2
>>> I.next()
3
>>> I.next()
4
>>> I.next()

Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
StopIteration

>>> L=[x+10 for x in range(10)]
>>> L

>>> res=[]
>>> for x in range(10):
...    res.append(x+10)
... 
>>> res
[10, 11, 12, 13, 14, 15, 16, 17, 18, 19]

root@10.1.6.200:python# vim 3.py 

#!/usr/bin/python2.5
for i in 'hello':  #序列里的字符串
  print i,
 
y = [1,2,3,4,5,6]  #列表
for i in y:
  print i,

root@10.1.6.200:python# python 3.py 

h e l l o 1 2 3 4 5 6

root@10.1.6.200:python# vim 3.py 

#!/usr/bin/python2.5
x='hello'
for i in range(len(x)):
  print x[i]
 
y = [1,2,3,4,5,6]
for i in range(len(y)):
  print y[i],

root@10.1.6.200:python# python 3.py 

h e l l o 1 2 3 4 5 6

root@10.1.6.200:python# vim 5.py 

#!/usr/bin/python2.5
z = {1:'a',2:'b',3:'c'}
for i in z:
  print z[i]

root@10.1.6.200:python# python 5.py 

a
b
c

root@10.1.6.200:python# cat 5.py 

#!/usr/bin/python2.5
z = {1:'a',2:'b',3:'c'}
print z.items()
for m,n in z.items():
  print m,n 

root@10.1.6.200:python# python 5.py

[(1, 'a'), (2, 'b'), (3, 'c')]
1 a
2 b
3 c