Tkinter计算器报错AttributeError: '_tkinter.tkapp'对象无insert属性如何解决

错误原因 #

• 直接触发报错的原因：insert() 是Tkinter输入框组件Entry的专属方法，你在add_digit函数中调用了主窗口对象root的insert方法，但root属于_tkinter.tkapp类，本身没有insert属性，因此触发属性不存在的报错。
• 隐藏问题：你创建输入框时的代码写为entr = Entry(root, bd = 4).grid(row = 0, column = 0, columnspan = 3)，grid()布局方法的返回值为None，因此变量entr实际存储的是空值，即使后续修改为调用entr.insert也会触发新的报错。

修复方案 #

1. 拆分输入框的实例创建和布局操作，先实例化Entry对象赋值给entr，再单独调用grid方法布局：

entr = Entry(root, bd = 4)
entr.grid(row = 0, column = 0, columnspan = 3)

2. 修改add_digit函数，将插入操作的调用对象改为输入框实例entr：

def add_digit(digit):
    entr.insert(0, digit)

如果需要数字追加在输入框末尾而非开头，可将insert(0, digit)改为insert(END, digit)。

修复后完整可运行代码 #

from tkinter import *

root = Tk()
root.title("Calculator")
root.geometry("400x480")
root.configure(bg = 'gray')

#commands for buttons
def add_digit(digit):
    entr.insert(END, digit)

#buttons
b7 = Button(root, text = '7', bd = 5, command = lambda : add_digit(7)).grid(row = 1, column = 0, stick = 'wens', padx = 5, pady = 5)
b8 = Button(root, text = '8', bd = 5, command = lambda : add_digit(8)).grid(row = 1, column = 1, stick = 'wens', padx = 5, pady = 5)
b9 = Button(root, text = '9', bd = 5, command = lambda : add_digit(9)).grid(row = 1, column = 2, stick = 'wens', padx = 5, pady = 5)
b4 = Button(root, text = '4', bd = 5, command = lambda : add_digit(4)).grid(row = 2, column = 0, stick = 'wens', padx = 5, pady = 5)
b5 = Button(root, text = '5', bd = 5, command = lambda : add_digit(5)).grid(row = 2, column = 1, stick = 'wens', padx = 5, pady = 5)
b6 = Button(root, text = '6', bd = 5, command = lambda : add_digit(6)).grid(row = 2, column = 2, stick = 'wens', padx = 5, pady = 5)
b1 = Button(root, text = '1', bd = 5, command = lambda : add_digit(1)).grid(row = 3, column = 0, stick = 'wens', padx = 5, pady = 5)
b2 = Button(root, text = '2', bd = 5, command = lambda : add_digit(2)).grid(row = 3, column = 1, stick = 'wens', padx = 5, pady = 5)
b3 = Button(root, text = '3', bd = 5, command = lambda : add_digit(3)).grid(row = 3, column = 2, stick = 'wens', padx = 5, pady = 5)
b0 = Button(root, text = '0', bd = 5, command = lambda : add_digit(0)).grid(row = 4, column = 1, stick = 'wens', padx = 5, pady = 5)

#entry
entr = Entry(root, bd = 4)
entr.grid(row = 0, column = 0, columnspan = 3)

root.mainloop()

内容的提问来源于stack exchange，提问作者user12962135