循环没有正确执行

rob*_*bin 3 python debugging comparison raw-input while-loop

class cga(object):
    ''''''
    def __int__(self,i,o):
        ''''''
        self.i = i
        self.o = o

    def get(self):
        ''''''
        self.i = []
        c = raw_input("How many courses you have enrolled in this semester?:")
        cout = 0
        while cout < c:
            n = raw_input("plz enter your course code:")
            w = raw_input("plz enter your course weight:")
            g = raw_input("plz enter your course grade:")
            cout += 1 
            self.i.append([n,w,g])
if __name__ == "__main__":
    test = cga()
    test.get()
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我的问题是如果我输入5,当程序询问我注册了多少课程.循环不会停止,程序将继续询问输入课程代码的重量等级.我调试时显示程序有cout = 6,但是它与c进行比较而while循环不会停止.

Dir*_*irk 6

问题是,raw_input返回一个字符串(不是数字),并且由于一些奇怪的历史原因,默认情况下,字符串可以与任何其他类型的对象进行比较(但是,结果是......奇数).

Python 2.6.5 (r265:79063, Oct 28 2010, 20:56:23) 
[GCC 4.5.0 20100604 [gcc-4_5-branch revision 160292]] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 1 < "2"
True
>>> 1 < "0"
True
>>> 1 < ""
True
>>> 
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在比较之前将结果转换为整数:

c = int(raw_input("How many courses you have enrolled in this semester?:"))
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  • "出于一些奇怪的历史原因"?并不是的.这是一个完全明智的理由:"明确比隐含更好".隐式转换是错误的. (2认同)