Question

在以下示例中，我将数据包含在字典中。应用一些代码后，正确的输出应为值 905 。但是，我当前的代码产生的值 1296 ，这是不正确的。

变量 non_udacity_enollments 看起来很好，因为它提供的输出与我正在学习的练习代码相同。

以下代码是我正在学习的练习代码的改编。

non_udacity_enrollments=[]
non_udacity_enrollments[:] = [v for v in enrollments if v.get('is_udacity')=='False']
paid_students = {}

    for enrollment in non_udacity_enrollments:
        if (not enrollment['is_canceled'] or
                enrollment['days_to_cancel'] > 7):
            account_key = enrollment['account_key']
            enrollment_date = enrollment['join_date']

            if (account_key not in paid_students or
                    enrollment_date > paid_students[account_key]):
                paid_students[account_key] = enrollment_date
    len(paid_students)

我想知道我哪里出错了。感谢。

根据要求，此处输出打印注册[0]

{u＆＃39;状态＆＃39;：你已经取消了＆＃39;，你很可能＆＃39;：你＆＃39;真的＆＃39;，你＆＃39; is_canceled＆＃39;：你＆＃39; True＆＃39;，你＆＃39; join_date＆＃39;：u＆＃39; 2014-11-10＆＃39;，u＆＃39; account_key＆＃39;：u＆＃39;＆＃39;＆＃39;，你＆＃ 39; cancel_date＆＃39 ;: u＆＃39; 2015-01-14＆＃39;，u＆＃39; days_to_cancel＆＃39;：u＆＃39; 65＆＃39;}

输出打印paid_students

{u＆＃39; 199＆＃39;：u＆＃39; 2015-05-30＆＃39;，u＆＃39;＆＃39;：u＆＃39; 2015-04-02＆＃39;，u＆＃ 39; 1200＆＃39;：u＆＃39; 2015-03-04＆＃39;，u＆＃39; 1175＆＃39;：u＆＃39; 2015-04-02＆＃39;，u＆＃39; 1269＆＃39; ：u＆＃39; 2015-08-21＆＃39;，u＆＃39; 1268＆＃39;：u＆＃39; 2015-04-06＆＃39;，u＆＃39; 1256＆＃39;：u＆＃39; 2015 -07-18＆＃39;，u＆＃39;＆＃39;：u＆＃39; 2015-05-12＆＃39;，u＆＃39; 1257＆＃39;：u＆＃39; 2015-07-09＆＃39 ;，＆＃39; 1145＆＃39;：u＆＃39; 2015-04-04＆＃39;，u＆＃39; 344＆＃39;：u＆＃39; 2015-01-11＆＃39;，u＆＃39; 345＆＃39;：u＆＃39; 2015-01-07＆＃39;，u＆＃39; 346＆＃39;：u＆＃39; 2014-12-08＆＃39;，u＆＃39; 347＆＃39;：u＆＃39; 2015-04-05＆＃39;，u＆＃39; 340＆＃39;：u＆＃39; 2015-04-01＆＃39;，u＆＃39; 341＆＃39;：u＆＃39; 2015-05 -10＆＃39;，u＆＃39; 342＆＃39;：u＆＃39; 2014-12-05＆＃39;，u＆＃39; 343＆＃39;：u＆＃39; 2014-12-07＆＃39;，你＆＃39;你＆＃39; 2014-11-10＆＃39;，你＆＃39;＆＃39;：你＆＃39; 2014-11-10＆＃39;，你＆＃39; 812＆＃ 39 ;: u＆＃39; 2015-07-09＆＃39;，u＆＃39;＆＃39;：u＆＃39; 2015-07-11＆＃39;，u＆＃39; 348＆＃39;：u＆＃39 ; 2015-03-05＆＃39;，u＆＃39; 349＆＃39;：u＆＃39; 2015-04-0 ....

Answer 1

is_canceled的值是字符串，而不是布尔值，因此您可以执行not enrollment['is_canceled']，因为这将始终为真。

与days_to_cancel的值相同 - 您将unicode值与整数进行比较，这也会给您带来奇怪的结果。

所以条件应该是这样的：

if (enrollment['is_canceled'] == 'False' or int(enrollment['days_to_cancel']) > 7):

列表代码代码提供了错误的输出

1 个答案: