修改了一個display參數，Django不能啟動，報錯為：
django.core.management.base.SystemCheckError: SystemCheckError: System check identified some issues:
ERRORS:
<class 'myApp.admin.GradesAdmin'>: (admin.E108) The value of 'list_display[3]' refers to 'ggirlbum', which is not a callable, an attribute of 'GradesAdmin', or an
attribute or method on 'myApp.Grades'.
翻譯一下：
“list_display[3]”的值是指“ggirlbum”，它不是可調用的、“GradesAdmin”屬性或
“myApp.Grades”上的屬性或方法。
然后我就找到錯誤了，全是自己手抖寫錯了ggirlbum：
list_display = ['pk', 'gname', 'gdate', 'ggirlbum', 'gboynum', 'isDelete']
改成↓↓↓↓↓↓↓↓↓↓↓↓↓
list_display = ['pk', 'gname', 'gdate', 'ggirlnum', 'gboynum', 'isDelete']