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Tkinter GUI freezes while running looping

I'm new to python coding and I have been working on a project which could click on an image based on a chosen color. I have been using a program which loops the search 50 times when I click the start button. However, I have been trying to implement a stop button, but the problem is that my code freezes when the loop is running. Any ideas?
I have heard to try threading but it seems very complicated and I have been unable to follow any tutorials properly in relation to my code. By the way, the image searched has been testing images I've been using stored inside the program files.
from imagesearch import *
import pyautogui
import tkinter as tk
from tkinter import *
from tkinter.ttk import *
import time
import threading
# ---Defined Programs---
def run():
global enterColor
enterColor = str(enterColorField.get())
program(enterColor)
def program(color):
whitePos = imagesearch_numLoop(str(color) + ".PNG", 0, 50)
pyautogui.moveTo(whitePos[0] + 20, whitePos[1] + 10)
pyautogui.click()
def stop():
print("Placeholder")
# ---Main Runner---
window = tk.Tk()
window.geometry("250x250")
window.configure(background="#181b54")
app = tk.Frame(window)
app.grid()
enterColorLabel = tk.Label(window, text="Enter Color:", bg="#181b54", fg="white")
enterColorLabel.place(x=10, y=50)
enterColorField = Combobox(window)
enterColorField['values'] = ("Black", "White")
enterColorField.current("0") # set the selected item
enterColorField.place(x=10, y=70)
submitButton = tk.Button(window, text="Start", bg="#66ff00", command=run)
submitButton.place(x=10, y=130)
stopButton = tk.Button(window, text="Stop", bg="red", command=stop)
stopButton.place(x=50, y=130)
window.mainloop()
#---New Python Script---
import cv2
import numpy as np
import pyautogui
import random
import time
def imagesearch_numLoop(image, timesample, maxSamples, precision=0.8):
pos = imagesearch(image, precision)
count = 0
while pos[0] == -1:
print(image+" not found, waiting")
count = count + 1
if count>maxSamples:
break
pos = imagesearch(image, precision)
return pos
Whenever clicking start, the whole code freezes. I can't even (x) out.

Here's a hopefully simple multiprocessing recipe that will work for you. We'll have three main functions. The first will be an example loop that you would put your processing inside. I included arguments in the function to show you that it's possible to pass args and kwargs while using multiprocessing.
def loop(a, b, c, d):
# Will just sleep for 3 seconds.. simulates whatever processing you do.
time.sleep(3)
return
Next is a function we will use to queue the multiprocessing process.
def queue_loop():
p = multiprocessing.Process(target = loop,
args = (1, 2),
kwargs = {"c": 3, "d": 4})
# You can pass args and kwargs to the target function like that
# Note that the process isn't started yet. You call p.start() to activate it.
p.start()
check_status(p) # This is the next function we'll define.
return
Then, you may be interested in knowing the status of your process throughout its execution. For example it is sometimes desirable to disable certain buttons while a command is being run.
def check_status(p):
""" p is the multiprocessing.Process object """
if p.is_alive(): # Then the process is still running
label.config(text = "MP Running")
mp_button.config(state = "disabled")
not_mp_button.config(state = "disabled")
root.after(200, lambda p=p: check_status(p)) # After 200 ms, it will check the status again.
else:
label.config(text = "MP Not Running")
mp_button.config(state = "normal")
not_mp_button.config(state = "normal")
return
Throwing this all together into one snippet:
import tkinter as tk
import multiprocessing
import time
def loop(a, b, c, d):
# Will just sleep for 3 seconds.. simulates whatever processing you do.
time.sleep(3)
return
def queue_loop():
p = multiprocessing.Process(target = loop,
args = (1, 2),
kwargs = {"c": 3, "d": 4})
# You can pass args and kwargs to the target function like that
# Note that the process isn't started yet. You call p.start() to activate it.
p.start()
check_status(p) # This is the next function we'll define.
return
def check_status(p):
""" p is the multiprocessing.Process object """
if p.is_alive(): # Then the process is still running
label.config(text = "MP Running")
mp_button.config(state = "disabled")
not_mp_button.config(state = "disabled")
root.after(200, lambda p=p: check_status(p)) # After 200 ms, it will check the status again.
else:
label.config(text = "MP Not Running")
mp_button.config(state = "normal")
not_mp_button.config(state = "normal")
return
if __name__ == "__main__":
root = tk.Tk()
mp_button = tk.Button(master = root, text = "Using MP", command = queue_loop)
mp_button.pack()
label = tk.Label(master = root, text = "MP Not Running")
label.pack()
not_mp_button = tk.Button(master = root, text = "Not MP", command = lambda: loop(1,2,3,4))
not_mp_button.pack()
root.mainloop()
The result is that when you click the "Using MP" button, the command buttons will be disabled and the process will be started without freezing your UI. Clicking the "Not MP" button will start the function like 'normal' and will freeze your UI as you noticed in your own code.

A simple answer is you cannot use while loop in GUI design.
But you can use the method .after(delay, callback=None) instead.
Here is an example:
from tkinter import *
root = Tk()
def loop():
print("Hi!")
root.after(1000, loop) # 1000 is equal to 1 second.
root.after(1000, loop) # This line is to call loop() in 1 second.
root.mainloop()

Python tkinter GUI freezing/crashing

from Tkinter import *
import tkFileDialog
import tkMessageBox
import os
import ttk
import serial
import timeit
import time
######################################################################################
class MyApp:
def __init__(self, parent):
########################################################
#Setup Frames
self.MiddleFrame = Frame(parent) #Middle Frame
self.MiddleFrame.pack()
#GLOBAL VARIABLES
self.chip_number = 0 #number of chip testing
###########################################
#Middle Frame setup
Label(self.MiddleFrame, text='Done').grid(row=8, column=1, sticky = E)
self.Done = Canvas(self.MiddleFrame, bg="yellow", width=10, height=10)
self.Done.grid(row=8, column=2)
Label(self.MiddleFrame, text='Chip Number:').grid(row=9, column=1, sticky = E)
#start button
self.button1 = Button(self.MiddleFrame,state=NORMAL, command= self.start_pre)
self.button1["text"]= "START"
self.button1.grid(row=1, column=2, sticky = E)
###########################################
#Action of Start Button
def start_pre(self):
x = 0
while x<10000:
self.start_button()
x=x+1
#Talking to Board
def start_button(self):
#increase chip count number and update
self.chip_number += 1
Label(self.MiddleFrame, text=str(self.chip_number)).grid(row=9, column=2, sticky = E)
#reset-yellow
self.reset_color()
print "Still Working", self.chip_number
self.Done.configure(background="green")
self.Done.update_idletasks()
###############################################################
#Color Boxes
#Reset
def reset_color(self):
self.Done.configure(background="yellow")
self.Done.update_idletasks()
###############################################################################################################
#Start Programs
root = Tk() #makes window
root.title("Interface")
myapp = MyApp(root) #this really runs program
root.mainloop() #keep window open
With my program, i first push the start button.
I will print "still working" and the GUi will update chip number and blink done light over and over. The start button go to function that will execute 10000 times. However after 3000 iterations, the gui freeze, but the program is still print "still working". How do I keep the gui from crashing?

There are many problems with your code. For one, this is fundamentally flawed:
while self.stop == True:
self.start_button()
time.sleep(0.5)
You simply can't expect a GUI to behave properly with code like that. As a general rule of thumb you should never have the main thread of a GUI call sleep. Causing sleep prevents the event loop from processing any events, including low level events such as requests to refresh the screen.
The use of sleep has been asked and answered many times on stackoverflow. You might find some of those questions useful. For example,
windows thinks tkinter is not responding
Python Tkinter coords function not moving canvas objects inside loop
How do widgets update in Tkinter?
Tkinter multiple operations
Python Tkinter Stopwatch Error
You have another problem that falls into the category of a memory leak. From that while loop, you call self.start_button() indefinitely. This happens about once a second, due to sleep being called for half a second in the loop, and another half a second in start_button.
Each time you call start_button, you create another label widget that you stack on top of all previous widgets in row 9, column 2. Eventually this will cause your program to crash. I'm surprised that it causes your program to fail so quickly, but that's beside the point.
My recommendation is to start over with a simple example that does nothing but update a label every second. Get that working so that you understand the basic mechanism. Then, once it's working, you can add in your code that reads from the serial port.

May I suggest that you start over with the following code? You can port in back to Python 2 if needed, but your program has been rewritten to use Python 3 and has been designed to use tkinter's ability to schedule future events with the after methods. Hopefully, you will find the code easier to follow.
import collections
import timeit
import tkinter
def main():
root = Application()
root.setup()
root.mainloop()
class Application(tkinter.Tk):
def setup(self):
mf = self.__middle_frame = tkinter.Frame(self)
self.__middle_frame.grid()
bf = self.__bot_frame = tkinter.Frame(self)
self.__bot_frame.grid()
self.__port_set = False
self.__chip_number = 0
self.__chip_pass_num = 0
self.__chip_fail_num = 0
self.__chip_yield_num = 0
self.__stop = True
self.__widgets = collections.OrderedDict((
('COT', 'Continuity Test'), ('CHE', 'Chip Erase'),
('ERT', 'Erase Test'), ('WRT', 'Write Test'),
('WIRT', 'Wire Reading Test'), ('WIT', 'Wire Reading Test'),
('WRAT', 'Write All Test'), ('DO', 'Done')))
for row, (key, value) in enumerate(self.__widgets.items()):
label = tkinter.Label(mf, text=value+':')
label.grid(row=row, column=0, sticky=tkinter.E)
canvas = tkinter.Canvas(mf, bg='yellow', width=10, height=10)
canvas.grid(row=row, column=1)
self.__widgets[key] = label, canvas
self.__cn = tkinter.Label(mf, text='Chip Number:')
self.__cn.grid(row=8, column=0, sticky=tkinter.E)
self.__display = tkinter.Label(mf)
self.__display.grid(row=8, column=1, sticky=tkinter.E)
self.__button = tkinter.Button(bf, text='START',
command=self.__start_pre)
self.__button.grid(sticky=tkinter.E)
def __start_pre(self):
self.__button['state'] = tkinter.DISABLED
self.__start_button(0)
def __start_button(self, count):
if count < 100:
self.__chip_number += 1
self.__display['text'] = str(self.__chip_number)
self.__widgets['DO'][1]['bg'] = 'yellow'
start_time = timeit.default_timer()
print('Still Working:', self.__chip_number)
self.after(500, self.__end_button, count)
else:
self.__button['state'] = tkinter.NORMAL
def __end_button(self, count):
self.__widgets['DO'][1]['bg'] = 'green'
self.after(500, self.__start_button, count + 1)
if __name__ == '__main__':
main()

Update time for recording

I doing a simple python GUI using tkinter to do screen recording.Basically, I am using ffmpeg commands at the backend with tkinter as the front end triggering the ffmpeg commands.There is something that I stuck with.I dont know why my time is unable to trigger off if I program in this way.
The code below is basically the recording method.You will notice that I am actually trying to update my tkinter GUI in the while loop.This method is actually in my class named Gui_Rec() which contains other methods I need for my screen recording program.
def rec(self):
global videoFile
mydate = datetime.datetime.now()
videoFile = mydate.strftime("\%d%b_%Hh%Mm.avi")
self.l['text']=os.path.expanduser('~')+"\Videos"
self.l1['text']=videoFile
self.b.config(state=DISABLED)
self.b1.config(state=ACTIVE)
t = Thread(target=self.rec_thread)#trigger another method using thread which will run ffmpeg commands here
t.start()
while True:
if self.count_flag == False:
break
self.label['text'] = str("%02dm:%02ds" % (self.mins,self.secs))
if self.secs == 0:
time.sleep(0)
else:
time.sleep(1)
if(self.mins==0 and self.secs==1):
self.b1.config(fg="white")
self.b1.config(bg="red")
self.b.config(fg="white")
self.b.config(bg="white")
if self.secs==60:
self.secs=0
self.mins+=1
self.label['text'] = str("%02dm:%02ds" % (self.mins,self.secs))
main.gui.update()
self.secs = self.secs+1
other method in the class Gui_Rec() then this below
def main():
gui = Gui_Rec()
gui.minsize(300,155)
gui.maxsize(390,195)
gui.title("Desktop REC")
gui.attributes("-topmost", 1)
gui.mainloop() #start mainloop of program
if __name__ == '__main__':
main()
Strangely, if I don't put the above section of code in the the def main(), the GUI will be update with the duration of the time running when rec button is pressed.I don't really know how to go about solving this.Tried putting it in another thread yet it doesn't work as well.Thank you everyone for your help.

The while loop is creating a conflict with Tkinter's mainloop. Threading or multiprocessing are solutions, but I'd recommend looking into Tkinter's after() method. Here's a simplified example of how to handle a timer using after:
from Tkinter import *
class App(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
self.mins = 0
self.secs = 0
# make a stringvar instance to hold the time
self.timer = StringVar()
self.timer.set('%d:%d' % (self.mins, self.secs))
Label(self, textvariable=self.timer).pack()
Button(self, text='Start', command=self._start_timer).pack()
Button(self, text='Stop', command=self._stop_timer).pack()
def _start_timer(self):
self.secs += 1 # increment seconds
if self.secs == 60: # at every minute,
self.secs = 0 # reset seconds
self.mins += 1 # and increment minutes
self.timer.set('%d:%d' % (self.mins, self.secs))
# set up the after method to repeat this method
# every 1000 ms (1 second)
self.repeater = self.after(1000, self._start_timer)
def _stop_timer(self):
self.after_cancel(self.repeater)
root = Tk()
App(root).pack()
mainloop()

Python, count down timer that doesn't sleep

I am new to python and i am trying to make a countdown timer on a button click. But i would like this countdown timer to start its countdown and place the current countdown value in the text area. Also i need the rest of the application to not sleep while this countdown is running. So far it will output the countdown in the console but will freeze the rest of the application. Can someone point me in the right direction?
from Tkinter import *
import time
import threading
import thread
class App:
def __init__(self, master):
frame = Frame(master)
frame.pack()
self.getvalue = Button(frame, text="Get the Text Area", command=self.thevalue)
self.getvalue.pack(side=LEFT)
self.text_area = Entry()
self.text_area.pack(side=RIGHT)
def thevalue(self):
print "In the value"
try:
t = threading.Thread(target=self.print_time("I am in print_time"))
t.daemon = True
t.start()
except:
print "Error: unable to start thread"
def print_time(self,bleh):
print bleh
print "The text area value is %s" % self.text_area.get()
boom=5
while boom >0:
time.sleep(1)
self.text_area.delete(0, END)
self.text_area.insert(0, boom)
print(boom)
boom -=1
root = Tk()
app = App(root)
root.mainloop()

threading.Thread(target=self.print_time("I am in print_time"))
This will not do what you want it to do. What happens here is that the function self.print_time is called and its return value is then passed to the constructor of threading.Thread.
You need to create the thread like this:
t = threading.Thread(target=self.print_time, args=("I am in print_time",))

Python GUI buttons wont execute

I'm writing a basic war-driving program. I have gotten it to loop the command to pull all the wireless access points near by. The problem is my stop button doesn't work and I am unable to update the label(I'm not even sure if I can update the label).
import sys, os, subprocess, re
from Tkinter import *
missionGO = 0
count = 0
class App:
def __init__(self, master):
frame = Frame(master)
frame.pack()
self.start = Button(frame, text="Start", fg="green",
command=self.startButtonClick)
self.start.grid(row=3)
self.stop = Button(frame, text="Stop", fg="red",
command=self.stopButtonClick)
self.stop.grid(row=3, column=1)
self.totalSSIDLabel = Label(frame, text="Current Access Points: ")
self.totalSSIDLabel.grid(row=0)
self.totalSSID = Label(frame, text=count)
self.totalSSID.grid(row=0, column=1)
def startButtonClick(self):
missionGO = 1
while (missionGO == 1):
wlan = getAccessPoints()
x = numberOfAccessPoints(wlan)
print x
return
def stopButtonClick(self):
missionGO = 0
return
def stop(event):
missionGO = 0
# Finds all wireless AP
def getAccessPoints():
X = subprocess.check_output("netsh wlan show network mode=Bssid",
shell=True)
return X
def numberOfAccessPoints(file):
count = 0
words = file.split()
for line in words:
if re.match('SSID', line):
count = count + 1
return count
#Main
root = Tk()
app = App(root)
root.mainloop()

Tkinter is single threaded. That means that while you are in the while loop inside startButtonClick, no other events are processed. The stop button won't call its command until the startButtonClick function finishes
You need to remember that your program is already running a global infinite loop: the event loop. There's no reason to put another infinite loop inside it. When you want something to run forever, the trick is to put one iteration on the event loop, then when it runs it puts another iteration on the event loop.
The other key to this is to make sure that one iteration of the loop is fast -- it needs to be well under a second (more like under 100ms) or the UI will become laggy.
The logic looks something like this:
def startButtonClick(self):
self.missionGO = 1
self._do_one_iteration()
def _do_one_iteration(self):
if self.missionGO == 1:
wlan = getAccessPoints()
x = numberOfAccessPoints(wlan)
print x
# this adds another iteration to the event loop
self.after(10, self._do_one_iteration)
def stopButtonClick(self):
self.missionGO = 0

I think the main thread is hanging in the while loop of the start button click. Since it's busy it won't even notice the stop button has been pressed.

I can't tell you exactly why your stop button doesn't work, but I think I got the idea of your programm. My suggestion is to establish two threads. The first thread for the UI, and the second for constantly checking wireless networks with given interval (your current code checks ASAP - bad practice, you should pause within the loop.
Since I have not dealt with multithreading in Tkinter, I can only provide you with entry points:
threading Module
time.sleep for updating the nearby networks every second or similar
Is there a way to request a function to be called on Tkinter mainloop from a thread which is not the mainloop?
Tkinter: invoke event in main loop
Good luck!