if、for、while、break、continue

if

 1 number=22
 2 guess=int(raw_input('Enter an integer:'))
 3 
 4 if guess==number:
 5     print 'Congratulation'
 6 elif guess<number:
 7     print 'low'
 8 else:
 9     print 'height'
10 print 'Done'

for

1 for i in range(4,10,2):
2     print i
3 else:
4     print 'for loop over'

rang 中第一位缺省默认为 0，第二位为 9（<第二位数值），第三位为步长，缺省默认为 1.

while

 1 number=23
 2 running=True
 3 
 4 while running:
 5     guest=int(raw_input('Enter an integer:'))
 6 
 7     if guest==number:
 8         print 'Yes'
 9         running=False
10     elif guest<number:
11         print 'low'
12     else:
13         print 'hight'
14 else:
15     print 'The while loop is over'
16 print 'done'

break

 1 number=22
 2 running=True
 3 while running:
 4     guess=int(raw_input('Enter an integer:'))
 5     if guess==number:
 6         print'yes'
 7         running=False
 8     elif guess==5:
 9         break
10     elif guess<number:
11         print 'low'
12     else:
13         print 'hight'

continue

1 while True:
2     s=raw_input('Enter someting:')
3     if s=='quit':
4         break
5     if len(s)<3:
6         continue
7     print 'Input is of sufficient length'

注：

break，continut 只能用于 for，while 这样的循环中，不然会报错。
SyntaxError: 'break' outside loop

posted @ 2013-08-11 22:16  Salm0n  阅读(1122)  评论(0)    收藏  举报