/* if ....else .... */

[root@localhost test1]# vim .py

//ADD

#!/usr/bin/python

if >:

    print 'hello python'

    print 'TRUE'

else:

    print 'FALSE'

[root@localhost test1]# python .py

FALSE

/* elif

如果if 不成立

     elif 成立，则执行elif

如果if不成立

     elif也不成立

      则执行else

*/

[root@localhost test1]# vim .py

//ADD

#!/usr/bin/python

if >:

    print 'hello python'

    print 'TRUE'

elif 'a':

    print 'b'

else:

    print 'FALSE'

[root@localhost test1]# python .py

b

[root@localhost test1]# vim .py

//ADD

#!/usr/bin/python

if >:

    print 'hello python'

    print 'TRUE'

elif :

    print 'b'

else:

    print 'FALSE'

[root@localhost test1]# python .py

FALSE

/*     利用 raw_input()输入或输出的是 字符串，

        始终 比整型数值大，所以当设计一个“分数脚本”时，没办法得出正确的结果

        可以利用 int('')这样的形式，将字符串转换为整型。

*/

[root@localhost test1]# vim .py

//ADD

#!/usr/bin/python

score = int(raw_input("Please input your score: "))

if score >= :

     print 'A'

     print 'excellent'

elif score >= :

     print 'B'

     print 'very good'

elif score >=7:

     print 'C'

     print 'good'

else:

     print 'D'

     print 'Sorry,you failed.'

[root@localhost test1]# python .py

Please input your score:

D

Sorry,you failed.

[root@localhost test1]# python .py

Please input your score:

C

good

[root@localhost test1]# python .py

Please input your score:

A

excellent

[root@localhost test1]# python .py

Please input your score:

B

very good

/* a.lower()  -- 这个lower()函数能够把大写的东西变成小写 */

[root@localhost test1]# vim .py

//ADD

#!/usr/bin/python

yn = raw_input("Please input [Yes/No]: ")

yn = yn.lower()

if yn == 'y' or yn == 'yes':

    print "programe is running..."

elif yn == 'n' or yn == 'no':

    print "programe is exit"

else:

    print "please input [Yes/No]"

[root@localhost test1]# python .py

Please input [Yes/No]: Yes

programe is running...

[root@localhost test1]# python .py

Please input [Yes/No]: No

programe is exit

[root@localhost test1]# python .py

Please input [Yes/No]: yes

programe is running...

[root@localhost test1]# python .py

Please input [Yes/No]: no

programe is exit

[root@localhost test1]# python .py

Please input [Yes/No]: ddd

please input [Yes/No]