Invalid command name while executing (“after” script)

问题

As solve this problem? I'm running this code, window is created, but in console appears message on the error. I think problem the fact that is "after" loop not terminate but the window already destroyed.

Code:

import Tkinter as tk
import time

class App():
    def __init__(self):
        self.root = tk.Tk()
        self.label = tk.Label(text="")
        self.label.pack()
        self.update_clock()
        self.root.mainloop()

    def update_clock(self):
        now = time.strftime("%H:%M:%S")
        self.label.configure(text=now)
        self.root.after(1000, self.update_clock)

app=App()

A message in console:

invalid command name "66120320callit"
while executing
"66120320callit"
("after" script)

Sorry for my small information in first post. I'm using Spyder IDE, and bugs see in spyder console, wherein run repeatedly my code. A description this bugs I find in the python bug tracker as "wait_variable hangs at exit"

回答1:

If you destroy the window, whatever "after" jobs that have already been scheduled may run. If the window is destroyed and this job interacts with a widget that has been deleted, you'll get this error.

You can either put a try around the code and ignore such an error, check that the window exists before trying to configure it, or put a handler in for when the main window is destroyed to delete any pending "after" jobs.

回答2:

I had this problem because my module was named "setup" and I also had a setup.py file. When calling setup.py somecommand, you will get "invalid command name 'somecommand'".

来源：https://stackoverflow.com/questions/26168967/invalid-command-name-while-executing-after-script