python 学习 二

前面看了for语句，现在看while语句。

while需要一个条件为真的情况下，重复执行语句，还用上面的例子，当输入数字为23时，执行结束。

eg.

 

#!/usr/bin/python
# Filename: while.py

number = 23
running = True

while running:
    guess = int(raw_input('Enter an integer : '))

    if guess == number:
        print 'Congratulations, you guessed it.'
        running = False # this causes the while loop to stop
    elif guess < number:
        print 'No, it is a little higher than that'
    else:
        print 'No, it is a little lower than that'
else:
    print 'The while loop is over.'
    # Do anything else you want to do here

print 'Done'

 

 

运行结果：python while.py
Enter an integer : 12
No, it is a little higher than that
Enter an integer : 455
No, it is a little lower than that
Enter an integer : 32
No, it is a little lower than that
Enter an integer : 23
Congratulations, you guessed it.
The while loop is over.
Done

 

Ps：while循环中使用一个else从句