按照步骤走，修改前 /polls/1/不会展示detail页面，用通用视图步骤就报下面的错误了： TypeErrorat /polls/1/ 'set' object is not reversible Request Method: GET Request URL: http://localhost:8000/polls/1/ Django Version: 2.2.6 Exception Type: TypeError Exception Value: 'set' object is not reversible Exception Location: D:\IDEA\Python\lib\site-packages\django\urls\resolvers.py in _populate, line 447 Python Executable: D:\IDEA\Python\python.exe Python Version: 3.7.4 Python Path: ['D:\\IDEA\\PycharmProjects\\mysite', 'D:\\IDEA\\PycharmProjects\\mysite', 'D:\\IDEA\\pycharm\\PyCharm 2019.1\\helpers\\pycharm_display', 'D:\\IDEA\\Python\\python37.zip', 'D:\\IDEA\\Python\\DLLs', 'D:\\IDEA\\Python\\lib', 'D:\\IDEA\\Python', 'D:\\IDEA\\Python\\lib\\site-packages', 'D:\\IDEA\\pycharm\\PyCharm 2019.1\\helpers\\pycharm_matplotlib_backend'] Server time: Thu, 14 Nov 2019 17:12:30 +0800 Error during template rendering In template D:\IDEA\PycharmProjects\mysite\polls\templates\polls\detail.html, error at line 12