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Elizen
V2EX  ›  Python

小白提问,关于 if 条件判断。

  •  
  •   Elizen · Apr 14, 2014 · 4094 views
    This topic created in 4415 days ago, the information mentioned may be changed or developed.
    我编写的代码是:

    age=raw_input('please enter your age:')

    if age >= 18:

    print 'your age is', age

    print 'adult'

    else:

    print 'your age is', age

    print 'teenager'

    然后运行后输入5,得到结果如下:

    please enter your age:5

    your age is 5

    adult

    为什么还是adult,不是teenager
    11 replies    1970-01-01 08:00:00 +08:00
    alioth310
        1
    alioth310  
       Apr 14, 2014   ❤️ 1
    输入的是字符串,需要把age转化成int
    davidli
        2
    davidli  
       Apr 14, 2014   ❤️ 1
    print('5'>18) 结果是True
    需要用int()把输入的string转成Int.
    yelite
        3
    yelite  
       Apr 14, 2014
    因为 raw_input 返回的是一个字符串

    if 判断可以这么写,int(age) >= 18
    lizheming
        4
    lizheming  
       Apr 14, 2014
    题外话,为啥不把print "your age is",age 提出来,然后再 print "adult" if age > 18 else "teenager"。
    Elizen
        5
    Elizen  
    OP
       Apr 14, 2014
    @yelite 谢谢啦。
    Elizen
        6
    Elizen  
    OP
       Apr 14, 2014
    @lizheming 我才刚开始....
    glasslion
        7
    glasslion  
       Apr 14, 2014
    @davidli
    @yelite
    @Elizen 这是范大爷为了逼你们升到Python3故意留下的坑
    dorentus
        8
    dorentus  
       Apr 14, 2014
    @glasslion
    我倒是觉得像 PHP、Javascript 那样莫名其妙地自动转类型的才是大坑……
    glasslion
        9
    glasslion  
       Apr 14, 2014   ❤️ 1
    @dorentus Python3 丢TypeError异常
    lizheming
        10
    lizheming  
       Apr 14, 2014
    @Elizen 好吧好吧,我就顺带吐个槽,LZ加油~
    1130335361
        11
    1130335361  
       Apr 14, 2014
    age=int(raw_input('please enter your age:'))
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