I am pretty new to using Tkinter and I am trying to build an app that displays a timer as one of its features. I am updating a label to display the time from a separate thread. On the display the time does not update smoothly. It freezes for short periods of time and then jumps a second or more. It there a way to keep the updates consistent so the timer is smooth?
It's a simple app so far so it doesn't seem like the CPU or main thread should be busy doing anything else. When you press a button it starts a separate thread that periodically sets the label text. I've tried sleeping between 0-0.1 seconds per update and the result is the same.
window = tk.Tk()
frame2 = tk.Frame(master=window, width=50, height=50, bg="yellow")
frame2.pack()
time_display = tk.Label(master=frame2, text="0.0")
time_display.pack()
update_thread = None
def play_pause():
global update_thread, stop_loop
if not update_thread:
stop_loop = False
update_thread = threading.Thread(target=update_timer_loop)
update_thread.start()
else:
stop_loop = True
update_thread = None
stop_loop = False
def update_timer_loop():
global window
start = time.time()
base_time = float(time_display["text"])
while not stop_loop:
current_time = time.time() - start + base_time
window.after(0, lambda: set_text(round(current_time, 2)))
time.sleep(0.1)
def set_text(text):
time_display["text"] = text
btn_play = tk.Button(master=frame1, text="Play/Pause", command=play_pause)
btn_play.pack(side=tk.LEFT)
You don't need threading at all in this. I see you tried to use after, and that's the correct approach. The only thing extra to know is that you can use after_cancel to cancel an upcoming event that you scheduled with after. Try this:
import tkinter as tk
import time
window = tk.Tk()
time_display = tk.Label(window, text="0.0")
time_display.pack()
update_thread = None
def play_pause():
global update_thread, start, base_time
if update_thread is None:
start = time.time()
base_time = float(time_display["text"])
update_timer_loop() # start the loop
else:
time_display.after_cancel(update_thread)
update_thread = None
def update_timer_loop():
global update_thread
current_time = time.time() - start + base_time
time_display["text"] = round(current_time, 2)
update_thread = window.after(100, update_timer_loop)
btn_play = tk.Button(master=window, text="Play/Pause", command=play_pause)
btn_play.pack(side=tk.LEFT)
window.mainloop()
Related
i want to animate a label text in tkinter (python). for that purpose, i am using time.sleep() method for updating 1 character in Label widget after a second but it is not updating Label widget instantly rather it is updating label at once at the end of timer. How could i fix this?. Here is my code:-
from tkinter import *
import time
global a
def update(a):
txt = 'Sample Text'
mylabel.configure(text=txt[0:a])
def timer():
global a
a = 0
lenth = len('Sample Text')
start = time.time()
while True:
# Do other stuff, it won't be blocked
time.sleep(0.1)
# When 1 sec or more has elapsed...
if time.time() - start > 1:
start = time.time()
a = a + 1
# This will be updated once per second
print("{} counter".format(a))
update(a)
# Count up to the lenth of text, ending loop
if a > lenth:
break
root = Tk()
root.geometry('300x300')
mylabel = Label(root, text="S", font=('Bell', 36, 'bold'))
mylabel.pack(pady=5)
root.after(3000, timer)
root.mainloop()
It is not recommended to use loop and time.sleep() in the main thread of a tkinter application because it will block the tkinter mainloop() from updating widgets until the loop exits. That is why you can only see the result after the loop completes.
Use .after() instead:
import tkinter as tk
root = tk.Tk()
#root.geometry('300x300')
txt = 'Sample Text'
lbl = tk.Label(root, font='Bell 36 bold', width=len(txt))
lbl.pack(pady=5)
def animate_label(text, n=0):
if n < len(text)-1:
# not complete yet, schedule next run one second later
lbl.after(1000, animate_label, text, n+1)
# update the text of the label
lbl['text'] = text[:n+1]
# start the "after loop" one second later
root.after(1000, animate_label, txt)
root.mainloop()
I tried making a fast reaction tester with Tkinter Module in Python, but when I clicked the Start button, it justs freezes the window. And I don't know how to recover that
Here's my code:
import webbrowser as wb
import time
import math
from random import *
from tkinter import *
from PIL import ImageTk, Image
seconds = 0
miliseconds = 0
minutes = 0
def reactionStarted():
global seconds, miliseconds, greenimages, redimages, minutes
# Put Image Green
reactionImage.config(image=greenimages)
# Random Countdown
countdownSecond = randint(4, 9)
countdownMiliSecond = randint(0, 9)
# Turn into float ( More Randomized )
countdownBonk = float(str(countdownSecond) + "." + str(countdownMiliSecond))
# Start Countdown
print(countdownBonk) # i was testing if this was the problem but its not
time.sleep(countdownBonk)
# Red image ( fast reaction part )
reactionImage.config(image=redimages)
# Timer
timeLoop = True
while timeLoop:
miliseconds += 1
time.sleep(0.1)
if miliseconds == 10:
seconds += 1
miliseconds = 0
elif seconds == 60:
seconds = 0
minutes += 1
def reactionCompleted():
global seconds, miliseconds, minutes
timeLoop = False
if not timeLoop:
reactionImage.config(image='', text=(
str(minutes) + "Minute(s)" + str(seconds) + "Second(s)" + str(miliseconds) + "Milisecond(s)"))
root = Tk()
root.title("Fast Reaction Test")
greenimages = ImageTk.PhotoImage(Image.open("green.png"))
redimages = ImageTk.PhotoImage(Image.open("red.png"))
reactionImage = Label(text='Click the button Below To Start!')
reactionImage.pack()
Start = Button(root, width=500, height=5, text="Click Here to Start", command=reactionStarted)
Start.pack()
Stop = Button(root, width=500, height=10, text="Stop (Spacebar)", command=reactionCompleted)
Stop.bind("<space>", reactionCompleted)
Stop.focus_force()
Stop.pack()
root.mainloop()
Really, thanks if you helped me out :)
Your error is that you are asking your program to enter an infinite loop when clicking the start button. The interpreter never leaves that loop, and thus the UI gets stuck without being able to update itself or receive input, because the interpreter is still stuck within your loop.
So you need to have another approach for this. Issues like these are normally handled by opening separate threads in your program, that can execute independently such that your main thread responsible for updating the UI window is not impacted by the child thread running your infinite loop. Then the main thread can at some point send a message to the child thread that the loop should be cancelled, when you user presses the stop button.
Handling this in tkinter has been made easy with the after() method, which simply put creates such an infinite loop in a separate thread to allow the main thread to keep running. I have below included a small example of how such an after loop can look, and you can try implementing that in your own code. If you still have problems, open a new question with more clarity.
import tkinter as tk
import time
class Timer:
def __init__(self):
self.root = tk.Tk()
self.sv = tk.StringVar()
self.start_time = None
self.after_loop = None
self.make_widgets()
self.root.mainloop()
def make_widgets(self):
tk.Label(self.root, textvariable=self.sv).pack()
tk.Button(self.root, text='start', command=self.start).pack()
tk.Button(self.root, text='stop', command=self.stop).pack()
def start(self):
self.start_time = time.time()
self.timer()
def timer(self):
self.sv.set(round(time.time() - self.start_time))
self.after_loop = self.root.after(500, self.timer)
def stop(self):
if self.after_loop is not None:
self.root.after_cancel(self.after_loop)
self.after_loop = None
Timer()
I'm writing a program with Python's tkinter library.
My major problem is that I don't know how to create a timer or a clock like hh:mm:ss.
I need it to update itself (that's what I don't know how to do); when I use time.sleep() in a loop the whole GUI freezes.
Tkinter root windows have a method called after which can be used to schedule a function to be called after a given period of time. If that function itself calls after you've set up an automatically recurring event.
Here is a working example:
# for python 3.x use 'tkinter' rather than 'Tkinter'
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()
Bear in mind that after doesn't guarantee the function will run exactly on time. It only schedules the job to be run after a given amount of time. It the app is busy there may be a delay before it is called since Tkinter is single-threaded. The delay is typically measured in microseconds.
Python3 clock example using the frame.after() rather than the top level application. Also shows updating the label with a StringVar()
#!/usr/bin/env python3
# Display UTC.
# started with https://docs.python.org/3.4/library/tkinter.html#module-tkinter
import tkinter as tk
import time
def current_iso8601():
"""Get current date and time in ISO8601"""
# https://en.wikipedia.org/wiki/ISO_8601
# https://xkcd.com/1179/
return time.strftime("%Y%m%dT%H%M%SZ", time.gmtime())
class Application(tk.Frame):
def __init__(self, master=None):
tk.Frame.__init__(self, master)
self.pack()
self.createWidgets()
def createWidgets(self):
self.now = tk.StringVar()
self.time = tk.Label(self, font=('Helvetica', 24))
self.time.pack(side="top")
self.time["textvariable"] = self.now
self.QUIT = tk.Button(self, text="QUIT", fg="red",
command=root.destroy)
self.QUIT.pack(side="bottom")
# initial time display
self.onUpdate()
def onUpdate(self):
# update displayed time
self.now.set(current_iso8601())
# schedule timer to call myself after 1 second
self.after(1000, self.onUpdate)
root = tk.Tk()
app = Application(master=root)
root.mainloop()
from tkinter import *
import time
tk=Tk()
def clock():
t=time.strftime('%I:%M:%S',time.localtime())
if t!='':
label1.config(text=t,font='times 25')
tk.after(100,clock)
label1=Label(tk,justify='center')
label1.pack()
clock()
tk.mainloop()
You should call .after_idle(callback) before the mainloop and .after(ms, callback) at the end of the callback function.
Example:
import tkinter as tk
import time
def refresh_clock():
clock_label.config(
text=time.strftime("%H:%M:%S", time.localtime())
)
root.after(1000, refresh_clock) # <--
root = tk.Tk()
clock_label = tk.Label(root, font="Times 25", justify="center")
clock_label.pack()
root.after_idle(refresh_clock) # <--
root.mainloop()
I have a simple answer to this problem. I created a thread to update the time. In the thread i run a while loop which gets the time and update it. Check the below code and do not forget to mark it as right answer.
from tkinter import *
from tkinter import *
import _thread
import time
def update():
while True:
t=time.strftime('%I:%M:%S',time.localtime())
time_label['text'] = t
win = Tk()
win.geometry('200x200')
time_label = Label(win, text='0:0:0', font=('',15))
time_label.pack()
_thread.start_new_thread(update,())
win.mainloop()
I just created a simple timer using the MVP pattern (however it may be
overkill for that simple project). It has quit, start/pause and a stop button. Time is displayed in HH:MM:SS format. Time counting is implemented using a thread that is running several times a second and the difference between the time the timer has started and the current time.
Source code on github
from tkinter import *
from tkinter import messagebox
root = Tk()
root.geometry("400x400")
root.resizable(0, 0)
root.title("Timer")
seconds = 21
def timer():
global seconds
if seconds > 0:
seconds = seconds - 1
mins = seconds // 60
m = str(mins)
if mins < 10:
m = '0' + str(mins)
se = seconds - (mins * 60)
s = str(se)
if se < 10:
s = '0' + str(se)
time.set(m + ':' + s)
timer_display.config(textvariable=time)
# call this function again in 1,000 milliseconds
root.after(1000, timer)
elif seconds == 0:
messagebox.showinfo('Message', 'Time is completed')
root.quit()
frames = Frame(root, width=500, height=500)
frames.pack()
time = StringVar()
timer_display = Label(root, font=('Trebuchet MS', 30, 'bold'))
timer_display.place(x=145, y=100)
timer() # start the timer
root.mainloop()
You can emulate time.sleep with tksleep and call the function after a given amount of time. This may adds readability to your code, but has its limitations:
def tick():
while True:
clock.configure(text=time.strftime("%H:%M:%S"))
tksleep(0.25) #sleep for 0.25 seconds
root = tk.Tk()
clock = tk.Label(root,text='5')
clock.pack(fill=tk.BOTH,expand=True)
tick()
root.mainloop()
I was writing a program with a start page, and two programs that are called from that start page. Both of the subprograms work by themselves. However, when I put them into my start page, the stopwatch timing label doesn't show up. If you are wondering, I put them into my program by doing:
import program
program.function()
Here is my start page program:
from Tkinter import *
class start_page:
def __init__(self,master):
self.master = master
self.frame = Frame(self.master)
self.countdown = Button(master, text = "Timer", command = self.c).pack()
self.stopwatch_butt = Button(master,text="Stopwatch",command=self.g).pack()
def g(self):
import stopwatch
stopwatch.f()
def c(self):
import timer_prog
timer_prog.timer()
self.master.after_cancel(timer_prog)
def main():
root = Tk()
s = start_page(root)
root.title("Timer Suite: Brian Ton")
root.mainloop()
main()
If I run this program, the timer program works fine, but the stopwatch doesn't show its label, only its buttons. I tried to clear all Tk after functions, and that didn't work, and I also tried to run the stopwatch program first, to no avail.
Here is my stopwatch program:
from Tkinter import *
import datetime
def s():
start.config(state='disabled')
stop.config(state="normal")
reset.config(state='disabled')
Start()
def Start():
if reset['state'] == 'disabled' and stop['state'] == 'normal':
hidden.set(str(int(hidden.get())+1))
root.update()
root.after(1000,Start)
curr = hidden.get()
g.set(str(datetime.timedelta(seconds=int(curr))))
print g.get()
else:
return None
def Stop():
start.config(state='disabled')
stop.config(state='disabled')
reset.config(state="normal")
def Reset():
start.config(state="normal")
stop.config(state="disabled")
reset.config(state='disabled')
hidden.set('0')
g.set(str(datetime.timedelta(seconds=0)))
def f():
global root,frame,master,hidden,g,timelabel,start,stop,reset
root = Tk()
frame = Frame(root)
master = root
hidden = StringVar()
g = StringVar()
hidden.set('0')
timelabel = Label(master,textvariable=g)
g.set(str(datetime.timedelta(seconds=int(0))))
timelabel.grid(row=1,column=2)
start = Button(master,text="Start",command = s,state="normal")
stop = Button(master,text="Stop",command = Stop,state = "disabled")
reset = Button(master,text="Reset",command = Reset,state = "disabled")
start.grid(row=2,column=1)
stop.grid(row=2,column=2)
reset.grid(row=2,column=3)
root.update()
root.mainloop()
And here is my timer program:
from Tkinter import *
import datetime
def get_seconds(h,m,s):
hr_sec = h * 3600
m_sec = m * 60
return hr_sec+m_sec+s
def timerstartstop():
hours = hour_entry.get()
minutes = minute_entry.get()
sec = second_entry.get()
if hours == "":
hours = 0
hour_entry.insert(0,"0")
if minutes == "":
minutes = 0
minute_entry.insert(0,"0")
if sec == "":
sec = 0
second_entry.insert(0,"0")
c = get_seconds(int(hours), int(minutes), int(sec))
global s
s = StringVar(master)
s.set(c)
if startstop['text'] == 'Stop':
global curr
curr = shown
s.set(-1)
if startstop['text'] == 'Reset':
startstop.config(text="Start")
s.set(c)
root.update()
shown.set(str(datetime.timedelta(seconds=int(s.get()))))
return None
countdown()
import winsound
def countdown():
startstop.config(text="Stop")
global shown
good = True
shown = StringVar(master)
shown.set(str(datetime.timedelta(seconds=int(s.get()))))
L = Label(master,textvariable=shown).grid(row=1,column=2)
if int(s.get()) == 0:
startstop.config(text="Reset")
while startstop['text'] != "Start":
root.update()
winsound.Beep(500,500)
elif int(s.get()) < 0:
good = False
shown.set(curr.get())
startstop.config(text="Reset")
else:
if good:
s.set(str(int(s.get())-1))
root.after(1000,countdown)
def ex():
root.after_cancel(countdown)
root.destroy()
def timer():
global root
global master
global frame
root = Tk()
master = root
frame = Frame(master)
global hour_entry
hour_entry = Entry(master,width=3)
hour_entry.grid(row=0,column=0)
colon_l = Label(master,text=':').grid(row=0,column=1)
global minute_entry
minute_entry = Entry(master,width=2)
minute_entry.grid(row=0,column=2)
colon_l2 = Label(master,text=':').grid(row=0,column=3)
global second_entry
second_entry = Entry(master,width=2)
second_entry.grid(row=0,column=4)
global startstop
startstop = Button(master,text="Start",command=timerstartstop)
e = Button(master,text="Exit",command=ex).grid(row=1,column=3)
startstop.grid(row=0,column=5)
root.mainloop()
In addition, I tried to run these two programs from a different starting menu that used the console, which worked.
The console program is:
import timer_prog
timer_prog.timer()
raw_input('next')
import stopwatch
stopwatch.f()
Attached are some screenshots of what the stopwatch program should look like vs what it does look like when called from the starting program.
Note: I can tell the program is running from the starting page, as it prints the current time each second. Also, I attached some screenshots
Stopwatch Program Run Directly
Stopwatch Program Run From The Start Page
Tkinter program should use only one Tk() - to create main window - and one mainloop() - to control all windows and widgets. If you use two Tk() and two mainloop() then it has problem - for example get()/set() may not work.
Subwindows should use Toplevel() instead of Tk().
Function which starts program (ie. run()) could run with parameter window (def run(window)) and then you can execute it as standalone program with
root = Tk()
run(root)
root.mainloop()
or after importing
run(Toplevel())
(without maniloop())
You can use if __name__ == "__main__" to recognize if program starts as standalone.
Example
main.py
from Tkinter import *
class StartPage:
def __init__(self, master):
self.master = master
master.title("Timer Suite: Brian Ton")
Button(master, text="Timer", command=self.run_timer).pack()
Button(master, text="Stopwatch", command=self.run_stopwatch).pack()
def run_stopwatch(self):
import stopwatch
window = Toplevel()
stopwatch.run(window)
def run_timer(self):
import timer_prog
window = Toplevel()
timer_prog.timer(window)
self.master.after_cancel(timer_prog)
def main():
root = Tk()
StartPage(root)
root.mainloop()
main()
stopwatch.py
from Tkinter import *
import datetime
def pre_start():
start_button.config(state='disabled')
stop_button.config(state='normal')
reset_button.config(state='disabled')
start()
def start():
global current_time
# stop_button['state'] can be 'normal' or 'active' so better use ` != 'disabled'`
if reset_button['state'] == 'disabled' and stop_button['state'] != 'disabled':
current_time += 1
time_var.set(str(datetime.timedelta(seconds=current_time)))
print(time_var.get())
master.after(1000, start)
def stop():
start_button.config(state='disabled')
stop_button.config(state='disabled')
reset_button.config(state='normal')
def reset():
global current_time
start_button.config(state='normal')
stop_button.config(state='disabled')
reset_button.config(state='disabled')
current_time = 0
time_var.set(str(datetime.timedelta(seconds=0)))
def run(window):
global master
global current_time, time_var
global start_button, stop_button, reset_button
master = window
current_time = 0
time_var = StringVar()
time_var.set(str(datetime.timedelta(seconds=0)))
time_label = Label(window, textvariable=time_var)
time_label.grid(row=1, column=2)
start_button = Button(master, text='Start', command=pre_start, state='normal')
stop_button = Button(master, text='Stop', command=stop, state='disabled')
reset_button = Button(master, text='Reset', command=reset, state='disabled')
start_button.grid(row=2, column=1)
stop_button.grid(row=2, column=2)
reset_button.grid(row=2, column=3)
if __name__ == '__main__':
# it runs only in standalone program
root = Tk()
run(root)
root.mainloop()
I'm very new to python and I'm trying to do a little project for myself, but I don't understand how to use the initial time variable from the start function in the stop function where I can do math with it. This is my code currently:
import time
import Tkinter
import tkMessageBox
top = Tkinter.Tk()
def start_time():
tkMessageBox.showinfo("Timer", "The timer will now begin")
initial = time.time()
return initial
def stop_time(initial):
final = time.time()
tkMessageBox.showinfo("Timer", final - initial)
Start = Tkinter.Button(top, text ="Start", command = start_time)
Stop = Tkinter.Button(top, text ="Stop", command = stop_time)
Start.pack()
Stop.pack()
top.mainloop()
Your functions need to agree on a common place for shared data. For this simple example, the module's global namespace is a good choice. All you need to do is add global initial to the functions that update it. For larger projects you may move to objects that hold the variables and the functions that update it, but this is fine for your goals.
import time
import Tkinter
import tkMessageBox
initial = 0
top = Tkinter.Tk()
def start_time():
global initial
tkMessageBox.showinfo("Timer", "The timer will now begin")
initial = time.time()
return initial
def stop_time():
# you could check for initial == 0 and display an error
final = time.time()
tkMessageBox.showinfo("Timer", final - initial)
Start = Tkinter.Button(top, text ="Start", command = start_time)
Stop = Tkinter.Button(top, text ="Stop", command = stop_time)
Start.pack()
Stop.pack()
top.mainloop()