Tkinter类开发问题：Entry绑定StringVar仍报AttributeError

我正在学习Python的Tkinter与面向对象编程，开发一个简易应用题生成器，点击“Create Document”按钮（绑定了调用.get()方法的函数）时出现AttributeError。已排查缩进、拼写、变量类型等问题，也查过线上资源但大多不涉及类或内容太简略，想知道哪里出错，或求合适的学习资源。

错误信息 #

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\riley\AppData\Local\Programs\Python\Python310\lib\tkinter\__init__.py", line 1921, in __call__
    return self.func(*args)
  File "C:\Users\riley\Documents\Pyth\Test.py", line 174, in get_inputs
    minadd = self.e_add_minvar.get()
AttributeError: 'BigWindow' object has no attribute 'e_add_minvar'

相关代码 #

rad_font = ('Cambria', 20)


class BigWindow:


    def __init__(self, root, title, geometry):
        self.root = root
        self.root.title(title)
        self.root.geometry(geometry)

        #labels for columns
        operator_label = Label(self.root, text = 'Choose options', font = ('cambria', 20, 'bold'))
        operator_label.grid(row = 0, column = 0)
        #create check buttons
        addbutt = IntVar()
        subbutt = IntVar()
        multbutt = IntVar()
        divbutt = IntVar()

        Check1 = Checkbutton(self.root, text = 'Addition', variable = addbutt, onvalue = 1, offvalue =0, font = rad_font, pady = 40)
        Check1.grid(row = 1, column = 0, sticky = 'W')
        Check2 = Checkbutton(self.root, text = 'Subtraction', variable = subbutt, onvalue = 1, offvalue =0, font = rad_font, pady = 40)
        Check2.grid(row = 2, column = 0, sticky = 'W')
        Check3 = Checkbutton(self.root, text='Multiplication', variable=multbutt, onvalue = 1, offvalue =0, font = rad_font, pady = 40)
        Check3.grid(row=3, column=0, sticky = 'W')
        Check4 = Checkbutton(self.root, text='Division', variable=divbutt, onvalue=1, offvalue = 0, font = rad_font, pady = 40)
        Check4.grid(row=4, column=0, sticky = 'W')

        #entry widgets for min max
        e_add_minvar = StringVar()
        e_add_minvar.set('32')
        e_add_min = Entry(self.root, bd = 4, relief = 'sunken', textvariable = e_add_minvar, 
        selectborderwidth = 5, font = ('Calibri', 20), width = 8)
        e_add_min.grid(column = 1, row = 1, padx = 40)

        #create/submit button
        create_button = Button(self.root, text = 'Create Document', command = self.get_inputs)
        create_button.grid(row = 3, column = 4)

        self.root.mainloop()
        #function to get all inputs to connect to submit/create button
    def get_inputs(self):
        minadd = self.e_add_minvar.get()
        print(minadd)

class Main:

    proot = Tk()
    Window1 = BigWindow(root, "Word Problem Generator", "900x500")

Main()

核心错误原因 #

你在__init__方法里定义的e_add_minvar是局部变量，仅在__init__的作用域内有效，而get_inputs方法尝试通过self.e_add_minvar访问它，自然找不到这个实例属性。

修正步骤 #

1. 将需要跨方法访问的变量绑定为实例属性，即在变量名前加上self.：

#entry widgets for min max
self.e_add_minvar = StringVar()
self.e_add_minvar.set('32')
e_add_min = Entry(self.root, bd = 4, relief = 'sunken', textvariable = self.e_add_minvar, 
selectborderwidth = 5, font = ('Calibri', 20), width = 8)
e_add_min.grid(column = 1, row = 1, padx = 40)

2. 调整get_inputs方法的缩进，使其与__init__方法同级（当前缩进属于__init__内部，会导致方法定义无效）。

3. 修复Main类里的变量引用错误：

class Main:
    def __init__(self):
        self.proot = Tk()
        self.Window1 = BigWindow(self.proot, "Word Problem Generator", "900x500")

Main()

• 先扎实掌握Python面向对象基础：明确实例属性、局部变量、类属性的区别与作用域。
• Tkinter类式开发重点：把需要在多个方法中访问的控件、变量都绑定为实例属性（self.xxx），避免局部变量无法跨方法访问的问题。
• 可以拆解成熟的Tkinter类项目代码，理解其中的属性和方法组织逻辑。

内容的提问来源于stack exchange，提问作者Riley Morris