Python：tkinter AttributeError

Question

我正在为课程分配工作而且我一直在获得一个AttributeError。这是我的代码：

from tkinter import *

class Lab12():
    def __init__(self, master):
        self.frm = Frame(master)
        self.frm.grid()
        self.buttons()
        self.basevalue = IntVar()
        self.expvalue = IntVar()
        self.strvalue = StringVar()

    def buttons(self):
        self.base = Scale (self.frm)
         self.base['orient'] = 'horizontal'
        self.base['length'] = 10
        self.base['from'] = 1
        self.base['to'] = 10
        self.base['variable'] = self.basevalue

        self.exp = Scale (self.frm)
        self.exp['orient'] = 'horizontal'
        self.exp['length'] = 25
        self.exp['from'] = 1
        self.exp['to'] = 25
        self.exp['variable'] = self.expvalue

        self.lbl = Label (self.frm)
        self.lbl['textvariable'] = self.strvalue

        self.result = Button (self.frm)
        self.result['text'] = "Click to get result"
        self.result['command'] = self.do_res

        self.base.grid(row = 0, column = 0)
        self.exp.grid(row = 1, column = 0)
        self.lbl.grid(row = 2, column = 1)
        self.result.grid(row = 2, column = 1)

    def do_res(self):
        x = self.basevalue.get()
        y = self.expvalue.get()
        self.strvalue.set(str(x) + ' raised to ' + str(y) + ' is ' + str(x     ** y))

def py_lab():
    lab = Tk()
    lab.title("lab12")
    lab.geometry("400x400")
    labclass = Lab12(lab)
    lab.mainloop()
py_lab()

错误：

Traceback (most recent call last):
  File "E:\CS 232\Lab 12\Lab12.py", line 53, in <module>
    py_lab()
  File "E:\CS 232\Lab 12\Lab12.py", line 51, in py_lab
    labclass = Lab12(lab)
  File "E:\CS 232\Lab 12\Lab12.py", line 10, in __init__
    self.buttons()
  File "E:\CS 232\Lab 12\Lab12.py", line 21, in buttons
    self.base['variable'] = self.basevalue
AttributeError: 'Lab12' object has no attribute 'basevalue'

如果我删除

self.base['variable'] = self.basevalue

行，然后我仍然得到self.expvalue和self.strvalue行的错误。我不确定是什么导致了这个问题，所以任何建议都有帮助。

Answer 1

您应该在__init__方法中的属性声明后调用方法 ... self.basevalue = IntVar() self.expvalue = IntVar() self.strvalue = StringVar() self.buttons() ... 。

{{1}}

Answer 2

在中调用(foldl * 1 '(1 2 3 4 5)) == 120 (foldr * 1 '(1 2 3 4 5)) == 120 后，只能初始化这些属性。在self.buttons()方法中反转顺序，然后它将起作用：

__init__