python中的进度条

Question

I have created token in tkinter window which changes the value each 10 seconds. I want to improve it and add progress bar. I know about ready libraries, but I want to use my personal code. My question is how to slow down the loop so the current value will be conveyed to string variable and after one second another value according to loop progress etc. My code just needs this "stopper". I could use 10 different functions and just triger after() but it doesn't look good and also my program crashes after a while.

def count(self):
        k =[" l", " l", " l"," l"," l"," l"," l"," l"," l"," l"]
        for x in range(9,0,-1):
                self.test_var.set(k[x]*x)

Answer 1

Edit: Here is a generalized method, which should give the idea of how to solve this problem. It contains all necessary parts, but it must be implemented into right places of your code.

To make sure your tkinter window wouldn't freeze during the update phase, you have to do the progress bar updating in another thread.

To call the method repeatedly after a certain time you can use time.sleep() method and a recursive method to call itself again and again.

import threading
import time


def change_progressbar(bar):
    # If there is more progress bar points to display, then do it
    if bar > 0:
        print(bar * ' l')  # Change your var here instead of printing
        time.sleep(10) # Wait 10 seconds
        change_progressbar(bar - 1) # Call itself again with one less point in a progress bar

# Let's call a method in new thread, with argument bar=10, which
# defines how many progress bar points there will be at start.
progressbar_thread = threading.Thread(target=change_progressbar, args=[10])
progressbar_thread.start()

# Output:  
# l l l l l l l l l l
# l l l l l l l l l
# l l l l l l l l
# l l l l l l l
# l l l l l l
# l l l l l
# l l l l
# l l l
# l l
# l

Answer 2

The "stopper" you are looking for is time.sleep()

The sleep function needs one argument, which is the amount of seconds to wait. This can also be a float like 0.5

You use it like this:

import time

while True:
    time.sleep(1)
    print("One second has passed")

This code will print something every second.