我的代码：
#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Created on Sun Jan 22 14:47:36 2017
@author: Jose Chong
"""
import json
try:
import tkinter as tk
except ImportError:
import Tkinter as tk
import os
import pymsgbox
filepath = os.path.expanduser(r'~\Documents\joseDzirehChongToDoList\toDoListSaveFile.json')
checkboxList = []
def checkSaveFile():
def checkExistenceOfSaveFile():
if not os.path.isdir(os.path.expanduser(r'~\Documents\joseDzirehChongToDoList')):
os.makedirs(os.path.expanduser(r'~\Documents\joseDzirehChongToDoList'), 777)
if not os.path.isfile(filepath):
open(filepath, 'w')
open(filepath).close()
def checkIfSaveFileIsEmpty():
global checkboxList
if os.path.getsize(filepath) == 0:
with open (filepath, 'w') as outfile:
json.dump(checkboxList, outfile)
with open(filepath) as infile:
checkboxList = json.load(infile)
checkExistenceOfSaveFile()
checkIfSaveFileIsEmpty()
try:
open(filepath, 'w')
open(filepath).close()
except (IOError, ValueError):
pymsgbox.alert("""You're not supposed to see this message ever. If you do, that means your save file is either missing or corrupted, and my methods of stopping that have failed. Please email me at 'josedzirehchong@gmail.com' with a copy of your save file so I can tell what went wrong.
Click the button below to exit, the red button in the corner doesn't work.""", 'Broken Save File')
checkSaveFile()
var = tk.IntVar()
def loadToJSON():
with open(filepath, 'w') as outfile:
json.dump(checkboxList, outfile)
class CheckboxRow(tk.Frame):
def __init__(self, master, text):
self.text = text
tk.Frame.__init__(self, master)
checkbox = tk.Checkbutton(self, text=text, variable=var)
checkbox.pack(side=tk.LEFT)
deleteItem = tk.Button(self, text="x", bg="red", fg="white",
activebackground="white", activeforeground="red",
command=self.destroyCheckbox)
deleteItem.pack(side=tk.RIGHT)
newItem = [self.text, var.get()]
self.master.master.checkboxList.append(newItem)
loadToJSON()
def destroyCheckbox(self, text):
self.text = text
newItem = [self.text, var.get()]
self.master.master.checkboxList.remove(newItem)
self.destroy()
loadToJSON()
class CheckboxArea(tk.Frame):
def add(self, name):
row = CheckboxRow(self, name)
row.pack(fill=tk.X)
class InputStuff(tk.Frame):
def __init__(self, master=None, **kwargs):
tk.Frame.__init__(self, master, **kwargs)
prompt = tk.Label(self, text="What do you want your checkbox to be for?")
prompt.pack()
bottomInput = tk.Frame(self)
self.entry = tk.Entry(bottomInput, bd=3)
self.entry.pack(side=tk.LEFT)
buttonConfirm = tk.Button(bottomInput, text="Confirm", command=self.drawCheckbox)
buttonConfirm.pack(side=tk.LEFT)
bottomInput.pack()
buttonDone = tk.Button(self, text = "Close Input", command=master.hideInputStuff)
buttonDone.pack()
def drawCheckbox(self, event=None):
self.master.add(self.entry.get())
self.entry.delete(0, tk.END)
class MainWindow(tk.Frame):
def __init__(self, master=None, **kwargs):
tk.Frame.__init__(self, master, **kwargs)
self.checkboxList = []
self.checkboxArea = CheckboxArea(self)
self.checkboxArea.pack(fill=tk.X)
self.inputStuff = InputStuff(self)
self.addButton = tk.Button(self, text="Add Item", command=self.showInputStuff)
self.hideInputStuff() # start with "add" button active
self.load()
def load(self):
for savedCheckbox in checkboxList:
checkboxRow = tk.Frame(checkboxArea)
checkboxRow.pack(fill=tk.X)
checkbox1 = tk.Checkbutton(checkboxRow, text=savedCheckbox[0], variable=var)
checkbox1.pack(side=tk.LEFT)
deleteItem = tk.Button(checkboxRow, text="x", bg="red", fg="white",
activebackground="white", activeforeground="red",
command=lambda c=savedCheckbox, r=checkboxRow: destroyCheckbox(c, r))
deleteItem.pack(side=tk.RIGHT)
loadToJSON()
def add(self, name):
self.checkbox_area.add(name)
self.checkboxList.append(name)
def showInputStuff(self):
self.addButton.pack_forget()
self.input_stuff.pack()
self.input_stuff.entry.focus()
self.master.bind('<Return>', self.input_stuff.drawCheckbox)
def hideInputStuff(self):
self.inputStuff.pack_forget()
self.addButton.pack()
self.master.unbind('<Return>')
def main():
master = tk.Tk()
master.title("To-Do List (with saving!)")
master.geometry("300x300")
win = MainWindow(master)
win.pack(fill=tk.X)
master.mainloop()
if __name__ == "__main__":
main()
我知道，它可怕地被打破了。我不想要任何其他东西的帮助，只需要AttributeError。
完整错误：
runfile('C:/Users/Josalina/Desktop/Coding/Language - Python/to-do-list-to-compile/toDoListToCompile.py', wdir='C:/Users/Josalina/Desktop/Coding/Language - Python/to-do-list-to-compile')
Traceback (most recent call last):
File "<ipython-input-78-a1f8f63a42cc>", line 1, in <module>
runfile('C:/Users/Josalina/Desktop/Coding/Language - Python/to-do-list-to-compile/toDoListToCompile.py', wdir='C:/Users/Josalina/Desktop/Coding/Language - Python/to-do-list-to-compile')
File "C:\Users\Josalina\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 866, in runfile
execfile(filename, namespace)
File "C:\Users\Josalina\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 102, in execfile
exec(compile(f.read(), filename, 'exec'), namespace)
File "C:/Users/Josalina/Desktop/Coding/Language - Python/to-do-list-to-compile/toDoListToCompile.py", line 51, in <module>
var = tk.IntVar()
File "C:\Users\Josalina\Anaconda3\lib\tkinter\__init__.py", line 351, in __init__
Variable.__init__(self, master, value, name)
File "C:\Users\Josalina\Anaconda3\lib\tkinter\__init__.py", line 233, in __init__
self._root = master._root()
AttributeError: 'NoneType' object has no attribute '_root'
我不知道这意味着什么。 Isn＆lt; IntVar（）是Tkinter的标准部分吗？为什么会引发错误？我如何解决它？此外，修复此错误可能不会使程序运行，它只是让我继续下一个错误。提前谢谢！
答案 0 :(得分：1)
在Tkinter程序中，必须通过在执行任何其他操作之前创建根窗口来初始化Tkinter。但是，您的代码会在创建根窗口之前尝试创建StringVar。
FWIW，我们可以在几行中重现该错误：
import tkinter as tk
var = tk.IntVar()
导致
Traceback (most recent call last):
File "./qtest.py", line 4, in <module>
var = tk.IntVar()
File "/opt/python3.6/lib/python3.6/tkinter/__init__.py", line 499, in __init__
Variable.__init__(self, master, value, name)
File "/opt/python3.6/lib/python3.6/tkinter/__init__.py", line 314, in __init__
self._root = master._root()
AttributeError: 'NoneType' object has no attribute '_root'
因此，您需要在执行var调用后定义master = tk.Tk()。它仍然可以是一个全局变量，但你真的应该尽量避免这种情况，特别是因为你已经在使用类来构建数据。
我还应该提到tk.Tk()调用不只是创建根窗口。它首先创建一个Tcl/tk解释器的实例; Python Tkinter代码本质上是创建和运行GUI的Tcl / tk调用的包装器。