How to run multiple processes in python without multithreading? For example consider the following problem:-
We have to make a Gui,which has a start button which starts a function(say, prints all integers) and there is a stop button, such that clicking it stops the function.
How to do this in Tkinter?
Then you need to bind the Button widget with the function which starts the working thread. For example:
import time
import threading
import Tkinter as tk
class App():
def __init__(self, root):
self.button = tk.Button(root)
self.button.pack()
self._resetbutton()
def _resetbutton(self):
self.running = False
self.button.config(text="Start", command=self.startthread)
def startthread(self):
self.running = True
newthread = threading.Thread(target=self.printints)
newthread.start()
self.button.config(text="Stop", command=self._resetbutton)
def printints(self):
x = 0
while self.running:
print(x)
x += 1
time.sleep(1) # Simulate harder task
With the self.running approach, you can end the thread gracefully only by changing its value. Note that the use of multiple threads serves to avoid blocking the GUI while printints is being executed.
I have read this previous question and I suppose why you explicitly asked here for a solution without multithreading. In Tkinter this solution can be used in a scenario where the other threads have to communicate with the GUI part. For example: filling a progressbar while some images are being rendered.
However, as it has been pointed in the comments, this approach is too complex for just printing numbers.
Here you can find a lot of information and more examples about Tkinter.
Edit:
Since your new question has been closed, I'll change the code here to clarify the last point.
