Python Tkinter：从列表框删除所有内容

Question

Hey guys pretty sure this is a simple fix, but I can't find anything. Basically I'm filling a listbox, and I need it to update (pseudo update) whenever a user clicks a label in the listbox.

My only problem is deleting all contents from the listbox. Below I have the function I implemented. Thank you in advance!

class SocketThreadedTask(threading.Thread):
def _init_(self, socket, callback):
    threading.Thread._init_(self)
    self.socket = socket
    self.callback = callback
    self.allChannels = None
    self.privateChannels = {}
    self.publicChannels = {}
    self.channelMessages = {}

def run(self):
    channels = None
    messages = None
    while True:
        try:
            message = self.socket.receive()
            if message[0] == "channels":
                self.allChannels = message[1]
                for key, value in self.allChannels.items():
                    if key[0] == '+':
                        oldKey = key
                        newKey = key[1:]
                        self.allChannels[newKey] = value
                        del self.allChannels[oldKey]
                        self.publicChannels[key] = value
                    elif key[0] == '-':
                        key = key[1:]
                        self.privateChannels[key] = value
                message = message[0]
                self.callback(None, self.allChannels, None)
            elif message[0] == "messages":
                self.channelMessages = messages = message[1]
                message = message[0]
                self.callback(message, None, messages)
            else:
                message = message[0]
                self.callback(message, None, None)
            if message == '/quit':
                self.callback('> You have been disconnected from the chat room.')
                self.socket.disconnect()
                break
        except OSError:
            break

class ChatWindow(tk.Frame):
def _init_(self, parent):
    tk.Frame._init_(self, parent)

    self.initUI(parent)

def initUI(self, parent):
    self.messageScrollbar = tk.Scrollbar(parent, orient=tk.VERTICAL)
    self.messageScrollbar.grid(row=0, column=3, sticky="ns")

    self.messageTextArea = tk.Text(parent, bg="white", state=tk.DISABLED, yscrollcommand=self.messageScrollbar.set, wrap=tk.WORD)
    self.messageTextArea.grid(row=0, column=0, columnspan=2, sticky="nsew")

    # list of users
    self.usersListBox = tk.Listbox(parent, bg="white")
    self.usersListBox.grid(row=0, column=4, padx=5, sticky="nsew")

    self.entryField = entry.BaseEntry(parent, placeholder="Enter message.", width=80)
    self.entryField.grid(row=1, column=0, padx=5, pady=10, sticky="we")

    self.send_message_button = tk.Button(parent, text="Send", width=10, bg="#CACACA", activebackground="#CACACA")
    self.send_message_button.grid(row=1, column=1, padx=5, sticky="we")

def update_window(self, message, channels, messages):
    if (message is None) and (messages is None):
        self.refresh_users(channels)
    elif (channels is None) and (message is None):
        self.refresh_messages(messages)
    elif (channels is None) and (messages is None):
        self.update_chat_window(message)

def refresh_users(self, channels = {}):
     self.usersListBox.delete(0, END)
     self.usersListBox.insert(0, "Channels")
     if bool(channels) is True:
          count = 1
          for key, value in channels.items():
               label = Label(self.userListBox, text=key)
               label.pack()
               label.bind(None, self.switch(label.cget("text")))
               self.usersListBox.insert(count, label)
               count += 1

I will attach 2 images

Answer 1

I'm surprised it's not crashing. I don't see your import statements, but contextually in your code you may have to write:

 self.usersListBox.delete(0, tk.END)

I think you imported Tkinter as tk, and END is a component of tk. Because it's not defined as such, is it possible that END is a variable in some wildcard-ed library or somewhere else in your code?

Specify tk.END or "end" in your delete function as in the example above and that would prevent this error.