流程控制--for序列

In []: list1 = [,,,]

In []: for i in list1:
   ...:     print i
   ...:

In []: for i in list1:
    print i,
   ...:
   

//range(头，尾，走多少步取值)
In []: range(,)
Out[]: [, , , , , , , , , ]

In []: range(,,)
Out[]: [, , , , , , , , , ]

In []: range(,,)
Out[]: [, , , , ]

In []: range(,,)
Out[]: [, , , ]

In []: range(,,)
Out[]: [, , ]

[root@localhost test1]# vim .py
//ADD
#!/usr/bin/python

for i in [i** for i in range(,) if i %  != ]:
    print i,

[root@localhost test1]# python .py

==================================
[root@localhost test1]# vim .py
//add
#!/usr/bin/python

sum =
for i in range(,):
    sum += i

print sum

[root@localhost test1]# python .py

/* xrange() 可以生成迭代的对象 ，

    但是如果直接执行时， 不会显示任何。

    需要在for循环语句中使用，才能发挥作用。
*/
In []: for i in xrange():
   ...:     print i
   ...:

In []: for i in xrange():
    print i,
   ...:

In []: xrange()
Out[]: xrange()

//两种方式新建字典
In []: dic = {'a':, 'b':}

In []: dic1 = dic.fromkeys('abc',)

In []: dic
Out[]: {'a': , 'b': }

In []: dic1
Out[]: {'a': , 'b': , 'c': }

In []: for k in dic:
   ...:     print k
   ...:
a
b

//取keys
In []: for k in dic1:
    print k
   ...:
a
c
b

//并取values
In []: for k in dic1:
    print k, dic1[k]
   ....:
a
c
b 

//格式化的输出
In []: for k in dic1:
    print "%s --> %s" % (k, dic1[k])
   ....:
a -->
c -->
b --> 

//两种的区别
In []: for i in dic1.items():print i
('a', )
('c', )
('b', )

In []: for k, v in dic1.iteritems():print k, v
a
c
b 

/* 利用循环做 “九九乘法表” */
[root@localhost test1]# vim .py
//ADD
#!/usr/bin/python

for i in xrange(,):
    for j in xrange(, i+):
        print "%sx%s=%s" % (j, i, j*i),
    print

/* 这里利用 逗号 来进行分行，并且打印出来 */

[root@localhost test1]# python .py
1x1=
1x2= 2x2=
1x3= 2x3= 3x3=
1x4= 2x4= 3x4= 4x4=
1x5= 2x5= 3x5= 4x5= 5x5=
1x6= 2x6= 3x6= 4x6= 5x6= 6x6=
1x7= 2x7= 3x7= 4x7= 5x7= 6x7= 7x7=
1x8= 2x8= 3x8= 4x8= 5x8= 6x8= 7x8=
1x9= 2x9= 3x9= 4x9= 5x9= 6x9= 7x9=