This question already has an answer here:
Tkinter, error maximum recursion depth exceeded
(1 answer)
Closed 5 years ago.
I'm new to Python and wanted to build a sleeptimer for training purposes.
I'm using Python 3.6.3 on Ubuntu.
I wanted a label which shows how many time is left till the Computer wents to sleep.
I'm using after() but every time I call the update Method it calls itself very often until I reach the maximum recursion depth with the Error:
RecursionError: maximum recursion depth exceeded while calling a Python object
I think that, for some reason the after(1000, self.update) command doesn't wait 1 second before calling the method again. Also I don't want a recursion, but call the method each second...
Can you tell me what I'm doing wrong?
class Application(Frame):
def startTimer(self):
self.start = time.time()
self.waiting = self.entry.get()*60000
self.update()
self.after(self.waiting, self.shutdown)
def update(self):
string = str(int(int(self.waiting/6000) + self.start - time.time())/10)
print(string)
self.label.config(text = string + " Minuts left")
self.after(1000, self.update())
def shutdown(self):
print("PSSST!")
def createWidgets(self):
self.entry = Scale(self, from_=5, to=120, orient=HORIZONTAL, resolution=5)
self.label = Label(self,text="time remaining")
self.start = Button(self, text="Start", fg="black",
command=self.startTimer)
self.quit = Button(self, text="QUIT", fg="red",
command=root.quit)
self.entry.pack(side="top")
self.label.pack(side="left")
self.start.pack(side="right")
self.quit.pack(side="bottom")
def __init__(self, master=None):
Frame.__init__(self, master)
self.pack()
self.createWidgets()
root = Tk()
app = Application(master=root)
app.mainloop()`
In this line:
self.after(1000, self.update())
You are not passing the self.update function to self.after, you are calling self.update() immediately and passing the result to self.after. This causes infinite recursion.
Related
I have been looking to create a code that opens a second tkinter window to display stuffs live while a program is running on my main window. However, doing so, my main window gets frozen during 5s and then displays stuff on my second window when it is completed.
Is there a way to live display in the second window ?
My code below:
import tkinter as tk
from tkinter import ttk
import time
class PopUpLog(tk.Tk):
def __init__(self, parent):
tk.Tk.__init__(self)
self.y=5
tk.Button(self.master, text="Write in pop-up", command=self.write).pack(side="left")
# canvas
frameL = tk.Frame(self)
frameL.pack(side="left", fill="both")
self.canvasL = tk.Canvas(frameL, height=800, width=800)
self.canvasL.pack(fill="both", expand=True)
# scrollbar
vsb = ttk.Scrollbar(self, orient="v", command=self.canvasL.yview)
vsb.pack(side="left", fill="y")
self.canvasL.configure(yscrollcommand=vsb.set)
self.canvasL.bind("<Configure>", lambda e:self.canvasL.configure(scrollregion=self.canvasL.bbox("all")))
def write(self, text="hi im a pop-up"):
for i in range(5):
self.canvasL.create_text(5, self.y, anchor='nw', justify='left', text=text)
self.y += 25
time.sleep(1)
class App(tk.Tk):
def __init__(self):
tk.Tk.__init__(self)
tk.Button(self, text="Open window", command=self.popup).pack(side="left")
def popup(self):
self.top = PopUpLog(self)
self.top.geometry("400x400")
self.top.title("pop-up")
self.top.mainloop()
if __name__ == "__main__":
root = App()
root.mainloop()
So far, the program runs for 5s and then displays everything in self.top. BUT I need a live display (made every time create_text is called) in self.top but I can't even get that.
I am sorry if this is redundant to another question asked but I couldn't find helpful enough information.
Thanks a lot !
time.sleep is the reason why your window is freezing. This is the case for virtually any GUI toolkit. If you want the updates to happen incrementally you can use the after method which will execute the callback you assign after a certain number of milliseconds.
Also there should only be one mainloop. There is no need to start one per window and doing so could cause problems.
Here is an example using the after method:
class PopUpLog(tk.Tk):
def __init__(self, parent):
tk.Tk.__init__(self)
self.y=5
self.c=5 # counter
tk.Button(self.master, text="Write in pop-up", command=self.write).pack(side="left")
# canvas
frameL = tk.Frame(self)
frameL.pack(side="left", fill="both")
self.canvasL = tk.Canvas(frameL, height=800, width=800)
self.canvasL.pack(fill="both", expand=True)
# scrollbar
vsb = ttk.Scrollbar(self, orient="v", command=self.canvasL.yview)
vsb.pack(side="left", fill="y")
self.canvasL.configure(yscrollcommand=vsb.set)
self.canvasL.bind("<Configure>", lambda e:self.canvasL.configure(scrollregion=self.canvasL.bbox("all")))
def write(self, text="hi im a pop-up"):
if self.c > 0:
self.canvasL.create_text(5, self.y, anchor='nw', justify='left', text=text)
self.y += 25
self.c -= 1 # reduce counter
self.after(1000, self.write) # call again in 1 second
else:
self.c = 5 # when counter is 0 reset counter
class App(tk.Tk):
def __init__(self):
tk.Tk.__init__(self)
tk.Button(self, text="Open window", command=self.popup).pack(side="left")
def popup(self):
self.top = PopUpLog(self)
self.top.geometry("400x400")
self.top.title("pop-up")
if __name__ == "__main__":
root = App()
root.mainloop()
This question already has answers here:
Call a function defined in another function
(4 answers)
Closed 3 years ago.
I am creating an application using Tkinter. I have two Threads, the first is an algorithm that looks for results and the second is my Tkinter window that displays the number of results found.
import time
from tkinter import *
from threading import Thread
global results
results = []
class thread(Thread):
def __init__(self, name):
Thread.__init__(self)
self.name = name
def run(self):
global results
if self.name == "algo":
algo()
elif self.name == "window":
window = Tk()
tmp = StringVar()
tmp.set(str(len(results)))
text = Label(window, textvariable=tmp, font=(None, 12))
text.place(x=10, y=15)
window.mainloop()
def algo():
global results
while True:
time.sleep(1)
results += [1]
print(len(results))
thread_1 = thread("algo")
thread_2 = thread("window")
thread_1.start()
thread_2.start()
thread_1.join()
thread_2.join()
The problem is that the textvariable does not update.
You can run the tkinter mainloop in the mainthread, and your function in a specially spawned new Thread. It does not appear necessary to have more:
import time
import tkinter as tk
from threading import Thread
def algo():
while True:
time.sleep(1)
result.set(result.get() + 1)
print(result.get())
root = tk.Tk()
result = tk.IntVar(value=0)
label = tk.Label(root, textvariable=result)
label.pack()
thread_1 = Thread(target=algo)
thread_1.start()
root.mainloop()
I have this following code where I am calling the function from the button which takes input from the widgets. It's a function which takes about 4 minutes to run and for solving the 'not responding' problem of tkinter window, I want to get the func process running on the different core and terminate as it can be called again via the application running on mainloop with a different argument. I read the documentation of multiprocessing and Pool seemed to be the choice here but I don't know how to frame it here. Tried a few things with error.
class database(tk.Tk):
def __init__(self, *args, *kwargs):
tk.Tk.__init__(self, *args, **kwargs):
container= tk.Frame(self, width=1000, height=1000)
container.pack(side="top", fill="both", expand= True)
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in ( msPage): #many more pages here
frame = F(container, self)
self.frames[F] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame(msPage)
def show_frame(self,cont):
frame = self,frames[cont]
frame.tkraise()
def MarkS(msVar):
ms.func(msVar.get()) # func takes about 4 mins
class msPage(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
msVar = StringVar()
msCal = Calendar(self, selectmode='day'
textvariable=msVar).pack(fill="both", expand=True)
# button2 calls MarkS
button2 = ttk.Button(self,
text="Get Data",
command=lambda: MarkS(msVar)).pack(pady=30, padx=10)
app = database()
app.geometry("1066x568")
app.minsize(width=670, height=550)
app.mainloop()
This is a standalone example that might help you get started:
from multiprocessing import Process
class ms_var_class():
value = None
def __init__(self, value):
self.value = value
def get(self):
return self.value
# This is to simulate type(ms)
class ms_class():
process = None
# This is for simulating your long running function
def func(self, ms_var):
print(ms_var)
def MarkS(msVar):
ms.process = Process(target=ms.func, args=(msVar.get(),))
ms.process.start()
# Call ms.process.join() later
ms_var = ms_var_class("bogus")
ms = ms_class()
MarkS(ms_var)
if ms.process is not None:
ms.process.join()
Thank you Mike for commenting and helping me get towards the solution
Here's how I did it
Create a global queue
q= queue.Queue()
Defined the function MarkS within the class msPage
def MarkS(msVar):
q.put([7 , datetime.datetime.strptime(msVar.get(), '%x').strftime('%d-%b-%Y').upper(),0])
ThreadedTask(q).start()
7 is the unique number of the 9 functions that I had for each page (class)
Made another class of ThreadedTask as in the link below
Tkinter: How to use threads to preventing main event loop from "freezing"
class ThreadedTask(threading.Thread):
def __init__(self,queue):
threading.Thread.__init__(self)
q = queue
def run(self):
items = q.get()
if items[0]==7:
ms.func(items[1])
ThreadedTask(q).start() creates a constructor object and the run function automatically starts depending on the argument here which is of course the 1st element of q which is a list of 3 in my case. It is detected and the desired function is run in another thread which prevents the tkinter window from closing.
Hope this helps! :)
I am designing a simple timer using Tkinter that changes color after a certain amount of time has elasped. I have a base timer program which works well, but now I want to modify it so the background changes color.
I have if statements that trigger on the appropriate intervals and then change the class attribute assigned to the background color, but I can't get the label color to update.
I understand the "makeWidgets" function runs only once and believe this is likely the source of my problem. I've experimented breaking out this function into the main program with mixed success. I am able to get the timer to work, but still cannot get the color to change. I have also tried writing a color change function/s but haven't had any success. I am inexperienced with python, tkinter and full-disclosure, I did not design the bulk of the base timer program.
I would really appreciate any direction/advice on how to get this working. I feel that I am either close, or in need of a complete re-work. Hopefully, the former is the case.
from tkinter import *
import time
class StopWatch(Frame):
global mincount
""" Implements a stop watch frame widget. """
def __init__(self, parent=None, **kw):
Frame.__init__(self, parent, kw)
self.start = 0.0
self.elapsedtime = 0.0
self.running = 0
self.timestr = StringVar()
self.makeWidgets()
self.color = 'green'
def makeWidgets(self): #this function only run once at setup
""" Make the time label. """
self.color='green' #this works
l = Label(self, textvariable=self.timestr, bg=self.color, font=("Helvetica",300), width=12, height=2)
self.setTime(self.elapsedtime)
l.pack(fill=X, expand=YES, pady=2, padx=2)
def update(self):
""" Update the label with elapsed time. """
self.elapsedtime = time.time() - self.start
self.setTime(self.elapsedtime)
self.timer = self.after(50, self.update)
def setTime(self, elap,):
global mincount
""" Set the time string to Minutes:Seconds:Hundreths """
minutes = int(elap/60)
seconds = int(elap - minutes*60.0)
hseconds = int((elap - minutes*60.0 - seconds)*100)
self.timestr.set('%02d:%02d:%02d' % (minutes, seconds, hseconds))
mincount = int(elap)
if mincount>=3:
print("yellow")
self.color='yellow' #has no effect
l.config(bg='yellow') #not in scope
#CHANGE COLOR TO YELLOW - call fx?
if mincount>=5:
print("red")
#CHANGE COLOR TO RED
def Start(self):
""" Start the stopwatch, ignore if running. """
if not self.running:
self.start = time.time() - self.elapsedtime
self.update()
self.running = 1
def Stop(self):
""" Stop the stopwatch, ignore if stopped. """
if self.running:
self.after_cancel(self.timer)
self.elapsedtime = time.time() - self.start
self.setTime(self.elapsedtime)
self.running = 0
def Reset(self):
""" Reset the stopwatch. """
self.start = time.time()
self.elapsedtime = 0.0
self.setTime(self.elapsedtime)
self.color='green'
def main():
root = Tk()
sw = StopWatch(root)
sw.pack(side=TOP)
Button(root, text='Start', command=sw.Start).pack(side=BOTTOM, fill=BOTH)
Button(root, text='Stop', command=sw.Stop).pack(side=BOTTOM, fill=BOTH)
Button(root, text='Reset', command=sw.Reset).pack(side=BOTTOM, fill=BOTH)
Button(root, text='Quit', command=root.quit).pack(side=BOTTOM, fill=BOTH)
current=sw.timestr
root.mainloop()
if __name__ == '__main__':
main()
You can't use l in your setTime function : l is a local variable in makeWidgets
it can't be used in setTime. To fix it you have to make l a variable part of the class in makeWidgets : self.label = ... for exemple. And after that use your new variable self.label in setTime : self.label.config("bg"="yellow")
Something can be improved in your if statement if mincount>=3: because if it's true you change the bg and after that you check if mincount>=5. You should do this:
if mincount>=5:
...
elif mincount >=3:
...
I have successfully created a threading example of a thread which can update a Progressbar as it goes. However doing the same thing with multiprocessing has so far eluded me.
I'm beginning to wonder if it is possible to use tkinter in this way. Has anyone done this?
I am running on OS X 10.7. I know from looking around that different OS's may behave very differently, especially with multiprocessing and tkinter.
I have tried a producer which talks directly to the widget, through both namespaces and event.wait, and event.set. I have done the same thing with a producer talking to a consumer which is either a method or function which talks to the widget. All of these things successfully run, but do not update the widget visually. Although I have done a get() on the IntVar the widget is bound to and seen it change, both when using widget.step() and/or widget.set(). I have even tried running a separate tk() instance inside the sub process. Nothing updates the Progressbar.
Here is one of the simpler versions. The sub process is a method on an object that is a wrapper for the Progressbar widget. The tk GUI runs as the main process. I also find it a little odd that the widget does not get destroyed at the end of the loop, which is probably a clue I'm not understanding the implications of.
import multiprocessing
from tkinter import *
from tkinter import ttk
import time
root = Tk()
class main_window:
def __init__(self):
self.dialog_count = 0
self.parent = root
self.parent.title('multiprocessing progess bar')
frame = ttk.Labelframe(self.parent)
frame.pack(pady=10, padx=10)
btn = ttk.Button(frame, text="Cancel")
btn.bind("<Button-1>", self.cancel)
btn.grid(row=0, column=1, pady=10)
btn = ttk.Button(frame, text="progress_bar")
btn.bind("<Button-1>", self.pbar)
btn.grid(row=0, column=2, pady=10)
self.parent.mainloop()
def pbar(self, event):
name="producer %d" % self.dialog_count
self.dialog_count += 1
pbar = pbar_dialog(self.parent, title=name)
event = multiprocessing.Event()
p = multiprocessing.Process(target=pbar.consumer, args=(None, event))
p.start()
def cancel(self, event):
self.parent.destroy()
class pbar_dialog:
toplevel=None
pbar_count = 0
def __init__(self, parent, ns=None, event=None, title=None, max=100):
self.ns = ns
self.pbar_value = IntVar()
self.max = max
pbar_dialog.pbar_count += 1
self.pbar_value.set(0)
if not pbar_dialog.toplevel:
pbar_dialog.toplevel= Toplevel(parent)
self.frame = ttk.Labelframe(pbar_dialog.toplevel, text=title)
#self.frame.pack()
self.pbar = ttk.Progressbar(self.frame, length=300, variable=self.pbar_value)
self.pbar.grid(row=0, column=1, columnspan=2, padx=5, pady=5)
btn = ttk.Button(self.frame, text="Cancel")
btn.bind("<Button-1>", self.cancel)
btn.grid(row=0, column=3, pady=10)
self.frame.pack()
def set(self,value):
self.pbar_value.set(value)
def step(self,increment=1):
self.pbar.step(increment)
print ("Current", self.pbar_value.get())
def cancel(self, event):
self.destroy()
def destroy(self):
self.frame.destroy()
pbar_dialog.pbar_count -= 1
if pbar_dialog.pbar_count == 0:
pbar_dialog.toplevel.destroy()
def consumer(self, ns, event):
for i in range(21):
#event.wait(2)
self.step(5)
#self.set(i)
print("Consumer", i)
self.destroy()
if __name__ == '__main__':
main_window()
For contrast, here is the threading version which works perfectly.
import threading
from tkinter import *
from tkinter import ttk
import time
root = Tk()
class main_window:
def __init__(self):
self.dialog_count = 0
self.parent = root
self.parent.title('multiprocessing progess bar')
frame = ttk.Labelframe(self.parent)
frame.pack(pady=10, padx=10)
btn = ttk.Button(frame, text="Cancel")
btn.bind("<Button-1>", self.cancel)
btn.grid(row=0, column=1, pady=10)
btn = ttk.Button(frame, text="progress_bar")
btn.bind("<Button-1>", self.pbar)
btn.grid(row=0, column=2, pady=10)
self.parent.mainloop()
def producer(self, pbar):
i=0
while i < 101:
time.sleep(1)
pbar.step(1)
i += 1
pbar.destroy()
def pbar(self, event):
name="producer %d" % self.dialog_count
self.dialog_count += 1
pbar = pbar_dialog(self.parent, title=name)
p = threading.Thread(name=name, target=self.producer, args=(pbar,))
p.start()
#p.join()
def cancel(self, event):
self.parent.destroy()
class pbar_dialog:
toplevel=None
pbar_count = 0
def __init__(self, parent, ns=None, event=None, title=None, max=100):
self.ns = ns
self.pbar_value = IntVar()
self.title = title
self.max = max
pbar_dialog.pbar_count += 1
if not pbar_dialog.toplevel:
pbar_dialog.toplevel= Toplevel(parent)
self.frame = ttk.Labelframe(pbar_dialog.toplevel, text=title)
#self.frame.pack()
self.pbar = ttk.Progressbar(self.frame, length=300, variable=self.pbar_value)
self.pbar.grid(row=0, column=1, columnspan=2, padx=5, pady=5)
btn = ttk.Button(self.frame, text="Cancel")
btn.bind("<Button-1>", self.cancel)
btn.grid(row=0, column=3, pady=10)
self.frame.pack()
self.set(0)
def set(self,value):
self.pbar_value.set(value)
def step(self,increment=1):
self.pbar.step(increment)
def cancel(self, event):
self.destroy()
def destroy(self):
self.frame.destroy()
pbar_dialog.pbar_count -= 1
if pbar_dialog.pbar_count == 0:
pbar_dialog.toplevel.destroy()
pbar_dialog.toplevel = None
def automatic(self, ns, event):
for i in range(1,100):
self.step()
if __name__ == '__main__':
main_window()
Doing something similar, I ended up having to use a combination of threads and processes - the GUI front end had two threads: one for tkinter, and one reading from a multiprocessing.Queue and calling gui.update() - then the back-end processes would write updates into that Queue
This might be a strange approach, but it works for me. Copy and paste this code to a file and run it to see the result. It's ready to run.
I don't have the patience to explain my code right now, I might edit it another day.
Oh, and this is in Python 2.7 I started programming two months ago, so I have not idea if the difference is relevant.
# -*- coding: utf-8 -*-
# threadsandprocesses.py
# Importing modules
import time
import threading
import multiprocessing
import Tkinter as tki
import ttk
class Master(object):
def __init__(self):
self.mainw = tki.Tk()
self.mainw.protocol("WM_DELETE_WINDOW", self.myclose)
self.mainw.title("Progressbar")
self.mainw.geometry('300x100+300+300')
self.main = tki.Frame(self.mainw)
self.RunButton = ttk.Button(self.main, text='Run',
command=self.dostuff)
self.EntryBox = ttk.Entry(self.main)
self.EntryBox.insert(0, "Enter a number")
self.progress = ttk.Progressbar(self.main,
mode='determinate', value=0)
self.main.pack(fill=tki.BOTH, expand=tki.YES)
self.progress.pack(expand=tki.YES)
self.EntryBox.pack(expand=tki.YES)
self.RunButton.pack()
print "The Master was created"
def dostuff(self):
print "The Master does no work himself"
data = range(int(self.EntryBox.get()))
S = Slave(self, data)
print "The Master created a Slave to do his stuff"
print "The Slave gets told to start his work"
S.start()
def myclose(self):
self.mainw.destroy()
return
def nextstep(self):
print "Good job, Slave, I see the result is"
print Master.results.get()
class Slave(threading.Thread):
def __init__(self, guest, data):
print "This is the Slave."
print "Nowdays, Work is outsourced!"
self.data = data
self.guest = guest
threading.Thread.__init__(self)
def run(self):
print "The Slave is outsourcing his work to Calcualte inc."
time.sleep(1)
Outsourcing = Calculate()
Results = Outsourcing.run(self.guest, self.data)
return Results
# unwrapping outside a class
def calc(arg, **kwarg):
return Calculate.calculate(*arg, **kwarg)
class Calculate(object):
def run(self, guest, data):
print"This is Calculate inc. ... how can I help you?"
time.sleep(1)
maximum = int(guest.EntryBox.get())
guest.progress.configure(maximum=maximum, value=0)
manager = multiprocessing.Manager()
queue = manager.Queue()
lock = manager.Lock()
print "Things are setup and good to go"
# Counting the number of available CPUs in System
pool_size = multiprocessing.cpu_count()
print "Your system has %d CPUs" % (pool_size)
# Creating a pool of processes with the maximal number of CPUs possible
pool = multiprocessing.Pool(processes=pool_size)
Master.results = pool.map_async(calc, (zip([self]*len(data), [lock]*len(data),
[queue]*len(data), data)))
for job in range(1, maximum+1):
queue.get() # this is an abuse I think, but works for me
guest.progress.configure(value=job)
# Properly close and end all processes, once we're done
pool.close()
pool.join()
print "All done"
guest.nextstep()
return
def calculate(self, lock, queue, indata):
lock.acquire()
print 'Reading values and starting work'
lock.release()
time.sleep(3) # some work
results = indata # The works results
lock.acquire()
print 'Done'
lock.release()
queue.put("Finished!")
return results
if __name__ == '__main__':
TheMaster = Master()
TheMaster.mainw.mainloop()