Question

此代码是一个更大的程序的一部分，该程序使用google Sheets API从云数据库中获取数据（虽然不相关，但是一点上下文也不会造成伤害！）

我在一个名为'oop.py'的python文件中拥有这黑色代码

class SetupClassroom:
    def __init__(self, arraynumber='undefined', tkroot='undefined'):
        self.arraynumber = arraynumber
        self.tkroot = tkroot

    def setarraynumber(self, number):
        from GUI_Stage_3 import showclassroom
        self.arraynumber = number
        print ('set array number:', number)

        showclassroom()

    def settkroot(self, tkrootinput):
        self.tkroot = tkrootinput

self.tkroot已由代码的另一部分分配。该位有效，因为我已经测试过它已被分配，但是，当我在另一个这样的文件中调用“ self.tkroot”时

def showclassroom():
    from oop import SetupClassroom
    username = current_user.username
    classnumber = getnumberofuserclassrooms(username)
    if SetupClassroom.arraynumber > classnumber:
        errorwindow('you are not enrolled in that many classrooms!')
    else:

        classtoget = SetupClassroom.arraynumber
        print('classtoget:', classtoget)
        root = SetupClassroom.tkroot
        name_label = Label(root, text=classtoget)

        getclassroom(username, classtoget)
SetupClassroom = SetupClassroom

我收到此错误

Exception in Tkinter callback
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/tkinter/__init__.py", line 1705, in __call__
    return self.func(*args)
  File "/Users/jonathansalmon/PycharmProjects/Coursework_GUI/GUI_Stage2_better.py", line 176, in <lambda>
    l0 = ttk.Button(teacher_root, text=button0text, command=lambda: (SetupClassroom.setarraynumber(SetupClassroom, number=button0text), SetupClassroom.settkroot(SetupClassroom, 'teacher_root')))
  File "/Users/jonathansalmon/PycharmProjects/Coursework_GUI/oop.py", line 99, in setarraynumber
    showclassroom()
  File "/Users/jonathansalmon/PycharmProjects/Coursework_GUI/GUI_Stage_3.py", line 29, in showclassroom
    root = SetupClassroom.tkroot
AttributeError: type object 'SetupClassroom' has no attribute 'tkroot'

我尝试在python控制台中对其进行设置，并且它可以正常工作，所以我不知道问题出在哪里。如果有人可以帮助，将不胜感激谢谢！约翰

Answer 1

您应该创建class的实例，它将在__init__中创建属性，self.tkroot是实例的属性，而不是class：

setupClassroom = SetupClassroom()
print(setupClassroom.tkroot)

希望对您有帮助。

python中的属性错误。对象没有属性

1 个答案: