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How to update tkinter texbox in Python during program runtime

I am writing a Python GUI program using tkinter to read data from an instrument based on a list of setpoints and to show the results of each reading in a tkinter scrolled textbox as the program is running, once the user clicks the "Start" button.
However, my program only shows the results at the end of all loops, rather than update the textbox after each loop. In actual usage, the program might run for many tens of minutes due to the large number of test points.
I tried using the .after method, to allow the GUI to update, but the program does not update the textbox during each loop.
How can I modify my code so that the tkinter textbox in the GUI is updated during each loop?
Here is my simplified code using random results as a sample instrument reading:
import tkinter as tk
import tkinter.scrolledtext as tkscrolled
from tkinter import ttk
def start_measurement():
import random
test_points = [tp for tp in range(1,5)]
for setpoint in test_points:
data_reading = random.normalvariate(setpoint,0.05/2)
data_results.insert(tk.INSERT,"Setpoint = {:.3f}, Reading = {:.3f}\n".format(setpoint, data_reading))
data_results.after(1000)
data_results.insert(tk.INSERT,"\nDone\n")
root = tk.Tk()
# Create main frame for entire program: mainframe
mainframe = ttk.Frame(root, padding="10 10 10 10", style='bgstyle.TFrame')
mainframe.grid(row=0, column=0, sticky=(tk.N, tk.W, tk.E, tk.S))
root.columnconfigure(0, weight=1)
root.rowconfigure(0, weight=1)
# Create Data Output Text Box with Vertical Scrollbar
data_label = ttk.Label(mainframe, text="Results")
data_label.grid(row=1, column=0, padx=(30,30), pady=(20,0), sticky=(tk.S,tk.W,tk.E))
data_results = tkscrolled.ScrolledText(mainframe, width=100, height=20)
data_results.grid(row=2, column=0, padx=(30,30), pady=(0,20), sticky=(tk.N,tk.W,tk.E))
start_button = ttk.Button(mainframe, width=15, text="Start", command=lambda:start_measurement())
start_button.grid(row=0, column=0, padx=(30,30), pady=(20,0), sticky=(tk.N, tk.W))
root.mainloop()

data_results.after(1000) behaves like time.sleep(1). So the updates are not shown until tkinter mainloop() takes back the control after the function exits.
You should use .after() like below:
def start_measurement(setpoint=1):
import random
if setpoint < 5:
start_button.config(state=tk.DISABLED) # prevent multiple executions
data_reading = random.normalvariate(setpoint, 0.05/2)
data_results.insert(tk.INSERT, "Setpoint = {:.3f}, Reading = {:.3f}\n".format(setpoint, data_reading))
# execute this function one second later with updated setpoint
data_results.after(1000, start_measurement, setpoint+1)
else:
data_results.insert(tk.INSERT, "\nDone\n")
start_button.config(state=tk.NORMAL) # enable for next execution

You can use root.after like this -
data_results.after(1000,lambda:data_results.insert(tk.INSERT,"\nDone\n"))
So, after approximately 1 second it inserts Done. And you should keep this out of the for loop -
def start_measurement():
test_points = [tp for tp in range(1,5)]
for setpoint in test_points:
data_reading = random.normalvariate(setpoint,0.05/2)
data_results.insert(tk.INSERT,"Setpoint = {:.3f}, Reading = {:.3f}\n".format(setpoint, data_reading))
data_results.after(1000,lambda:data_results.insert(tk.INSERT,"\nDone\n"))

Change your code as follows.
def start_measurement():
import random
test_points = [tp for tp in range(1,5)]
for setpoint in test_points:
data_reading = random.normalvariate(setpoint,0.05/2)
data_results.insert(tk.INSERT,"Setpoint = {:.3f}, Reading = {:.3f}\n".format(setpoint, data_reading))
data_results.update()
data_results.after(1000)
data_results.insert(tk.INSERT,"\nDone\n")
Add data_results.update() to your code.This updates your textbox every second.After all iteration You get 'Done' displayed.

Python - Tkinter Manage Frames

I have a small script which is organized in 3 frames:
1 in the first row
1 in the second row Left
1 in the second row right
I press the button in the first row frame and hand over the input value to the Label in the second row in the left.
Here my code:
import tkinter as tk
# Create Window
root = tk.Tk()
# Define String Variable
Name = tk.StringVar()
# Organize root window in 3 frames
EntryFrame = tk.Frame(root)
MainLeftFrame = tk.Frame(root)
MainRightFrame = tk.Frame(root)
# Create Buttons, Entry and Labels
NameLabel = tk.Label(MainLeftFrame, textvariable=Name)
InputName = tk.Entry(EntryFrame, width=20,bg='yellow')
SubmitButton = tk.Button(EntryFrame, text='Submit', command=lambda:action())
# Define what happens when press button reset
def reset():
MainLeftFrame.forget()
MainRightFrame.forget()
EntryFrame.pack()
# Define what happens when button is pressed
def action():
Name.set(InputName.get())
ResetButton = tk.Button(MainRightFrame, text='Reset', command=lambda: reset())
ResetButton.pack()
Placeholder = tk.Label(MainRightFrame, text="place holder")
Placeholder.pack(side="top")
EntryFrame.forget()
# Pack Widgets
EntryFrame.pack(side='top')
MainLeftFrame.pack(side='left')
MainRightFrame.pack(side='right')
InputName.pack()
SubmitButton.pack()
NameLabel.pack()
#mainloop
root.mainloop()
Now to my question:
When I press the "Submit" Button for the Second time (after pressing Reset Button) nothing is happening :(
Thanks in advance!

The reason of your program not working is that, after using forget on the MainLeftFrame and MainRightFrame you aren't packing them again when the action function is called. Adding these 2 lines of code in action function should make it work. BUT
MainLeftFrame.pack()
MainRightFrame.pack()
That's not the only issue, defining new widgets every time the function is called and packing them will additively increase the same widget set over and over again. To avoid this, you would have to predefine them and them perform forget and repacking. But a better thing to do would be to have a dedicated frame for them, so that it becomes easy for you to toggle. I have tried rewriting your script, let me know if this is what you wanted.
from tkinter import *
def reset():
entry_frame.pack()
main_frame.pack_forget()
def submit():
entry_frame.pack_forget()
main_frame.pack()
name.set(name_entry.get())
root=Tk()
entry_frame=Frame(root)
entry_frame.pack()
name_entry=Entry(entry_frame)
name_entry.pack(side='top')
submit_button=Button(entry_frame,text='Submit',command=submit)
submit_button.pack(side='top')
main_frame=Frame(root)
reset_button=Button(main_frame,text='Reset',command=reset)
reset_button.pack(side='top')
name=StringVar()
name_label=Label(main_frame,textvariable=name)
name_label.pack(side='left')
placeholer_label=Label(main_frame,text='placeholer')
placeholer_label.pack(side='right')
root.mainloop()

Getting variable out of Tkinter

I would like to ask if anyone knows how to get out a variable from an Entry in Tkinter to be used in future calculation.
Let us assume that I want to create a prompt where the user needs to place two numbers in the two different Entry widgets.
These numbers are to be used in another script for calculation. How can I retrieve the values from the prompt created in Tkinter?
In my opinion, I would need to create a function with the code bellow and make it return the value from the Tkinter prompt. However, I cannot return the numbers because I'm destroying the root window. How can I get pass this, preferably without global variables.
Best Regards
from tkinter import *
from tkinter import ttk
#Start of window
root=Tk()
#title of the window
root.title('Title of the window')
def get_values():
values=[(),(value2.get())]
return values
# Creates a main frame on the window with the master being the root window
mainframe=ttk.Frame(root, width=500, height=300,borderwidth=5, relief="sunken")
mainframe.grid(sticky=(N, S, E, W))
###############################################################################
#
#
# Label of the first value
label1=ttk.Label(master=mainframe, text='First Value')
label1.grid(column=0,row=0)
# Label of the second value
label2=ttk.Label(master=mainframe, text='Second Value')
label2.grid(column=0,row=1)
###############################################################################
#
#
# Entry of the first value
strvar1 = StringVar()
value1 = ttk.Entry(mainframe, textvariable=strvar1)
value1.grid(column=1,row=0)
# Entry of the second value
strvar2 = StringVar()
value2 = ttk.Entry(mainframe, textvariable=strvar2)
value2.grid(column=1,row=1)
# Creates a simplle button widget on the mainframe
button1 = ttk.Button(mainframe, text='Collect', command=get_values)
button1.grid(column=2,row=1)
# Creates a simplle button widget on the mainframe
button2 = ttk.Button(mainframe, text='Exit', command=root.destroy)
button2.grid(column=2,row=2)
root.mainloop()

You use a class because the class instance and it's variables remain after tkinter exits.https://www.tutorialspoint.com/python/python_classes_objects.htm And you may want to reexamine some of your documentation requirements, i.e. when the statement is
"root.title('Title of the window')", adding the explanation "#title of the window" is just a waste of your time..
""" A simplified example
"""
import sys
if 3 == sys.version_info[0]: ## 3.X is default if dual system
import tkinter as tk ## Python 3.x
else:
import Tkinter as tk ## Python 2.x
class GetEntry():
def __init__(self, master):
self.master=master
self.entry_contents=None
self.e = tk.Entry(master)
self.e.grid(row=0, column=0)
self.e.focus_set()
tk.Button(master, text="get", width=10, bg="yellow",
command=self.callback).grid(row=10, column=0)
def callback(self):
""" get the contents of the Entry and exit
"""
self.entry_contents=self.e.get()
self.master.quit()
master = tk.Tk()
GE=GetEntry(master)
master.mainloop()
print("\n***** after tkinter exits, entered =", GE.entry_contents)

So, I have taken Curly Joe's example and made a function with the his sketch
The final result, for anyone wanting to use this as a template for a input dialog box:
def input_dlg():
import tkinter as tk
from tkinter import ttk
class GetEntry():
def __init__(self, master):
self.master=master
self.master.title('Input Dialog Box')
self.entry_contents=None
## Set point entries
# First point
self.point1 = ttk.Entry(master)
self.point1.grid(row=0, column=1)
self.point1.focus_set()
# Second point
self.point2 = ttk.Entry(master)
self.point2.grid(row=1, column=1)
self.point2.focus_set()
# labels
ttk.Label(text='First Point').grid(row=0, column=0)
ttk.Label(text='Second Point').grid(row=1, column=0)
ttk.Button(master, text="Done", width=10,command=self.callback).grid(row=5, column=2)
def callback(self):
""" get the contents of the Entries and exit the prompt"""
self.entry_contents=[self.point1.get(),self.point2.get()]
self.master.destroy()
master = tk.Tk()
GetPoints=GetEntry(master)
master.mainloop()
Points=GetPoints.entry_contents
return list(Points)

In python, functions are objects, as in get_values is an object.
Objects can have attributes.
Using these two, and the knowledge that we can't really return from a button command, we can instead attach an attribute to an already global object and simply use that as the return value.
Example with button
try: # In order to be able to import tkinter for
import tkinter as tk # either in python 2 or in python 3
except ImportError:
import Tkinter as tk
def on_button_press(entry):
on_button_press.value = entry.get()
entry.quit()
def main():
root = tk.Tk()
entry = tk.Entry(root)
tk.Button(root, text="Get Value!", command=lambda e = entry : on_button_press(e)).pack()
entry.pack()
tk.mainloop()
return on_button_press.value
if __name__ == '__main__':
val = main()
print(val)
Minimalistic example
Similarly modules are also objects, if you want to avoid occupying global namespace extremely, you can attach a new attribute to the module you're using
See:
try: # In order to be able to import tkinter for
import tkinter as tk # either in python 2 or in python 3
except ImportError:
import Tkinter as tk
if __name__ == '__main__':
tk.my_value = lambda: [setattr(tk, 'my_value', entry.get()), root.destroy()]
root = tk.Tk()
entry = tk.Entry(root)
root.protocol('WM_DELETE_WINDOW', tk.my_value)
entry.pack()
tk.mainloop()
print(tk.my_value)

How to make randomly pop some gui without stopping the script #python 2.7

I'm relatively new to python, so please bear with me.
My question has two aspects:
First, I'm trying to make a GUI that randomly pops different sentences to the user, every time in a new frame.
Second, I want the user to be able to close the GUI without stopping the script, like if it was running in the background.
here is my code:
import Tkinter as tk
import random
number = random.randint(0,13)
sentence = {contains 13 sentences
}
window = tk.Tk()
window.output = tk.Label(text = sentence[number])
window.title("I Always See You")
window.geometry("300x150")
def next():
rand= random.randint(0, 13)
window2 = tk.Tk()
window2.output = tk.Label(text = sentence[rand])
window2.output.pack(side="top", fill="x", expand=True)
window2.title("I Always See You")
window2.geometry("300x150")
window.output.pack(side="top", fill="x", expand=True)
choice()
window.after(1000, next)
window.mainloop()
My problem: when my second frame pops, there isn't any text showing, and if it does have something popping, it appears in the first frame.
also, how can you insert a random float in .after() ?
Thank you so much for your help!
cheers

You do not see the text in the second window because Tkinter cannot handle two main windows. You need to use the Toplevel class for the others. In addition, you haven't specified the parent of the label in next, so it will probably be packed inside window instead of window2.
In addition, you need 14 sentences because randint, unlike randrange includes both end points.
To set a random time in after, just use randint because it expects an integer number of ms.
To achieve what you want I suggest you to create a main window that will be withdraw (it will run in the background). Then popup Toplevels with random sentences. You need to call again after inside the next function if you want the windows to keep poping up. To prevent the after to be cancelled if the user closes the Toplevel, I called the after method from the withdrawn main window:
import Tkinter as tk
import random
number = random.randint(0,13)
sentence = {i: str(i) for i in range(14)}
def next():
rand=random.randint(0, 13)
window2 = tk.Toplevel(root)
window2.output = tk.Label(window2, text=sentence[rand])
window2.output.pack(side="top", fill="x", expand=True)
window2.title("I Always See You")
window2.geometry("300x150")
tps = random.randint(1000, 10000)
root.after(tps, next)
root = tk.Tk()
root.withdraw() # hide root window
window = tk.Toplevel(root)
window.output = tk.Label(window, text=sentence[number])
window.title("I Always See You")
window.geometry("300x150")
window.output.pack(side="top", fill="x", expand=True)
tps = random.randint(1000, 10000)
root.after(tps, next)
root.mainloop()

How to make a button open a new window?

I am making a simple GUI that starts with a main menu them the user can click a button to proceed to a new window which has a picture of a keyboard and the user can press key on their keyboard to play the paino. Right now I cant figure out how to make a button that when pressed closes the main menu (labeled mainMenu()) and open the game menu (playGame).
import tkinter
from tkinter import *
class mainMenu:
def _init_(self, master):
frame = Frame(master)
frame.pack()
self.quitButton = Button(frame, text = "Quit", command = frame.quit)
self.quitButton.pack(side = LEFT)
self.proceedButton = Button(frame, text = "Play", command = playGame)
self.proceedButton.pack(side = LEFT)
def playGame(self):
frame.quit
gameMenu()
def gameMenu(self):
root = Tk()
b = mainMenu(root)
topFrame = Frame(root)
topFrame.pack()
bottomFrame = Frame(root)
bottomeFrame.pack(side = BOTTOM)
photo = PhotoImage(file = "piano.png")
label = Label(root, image = photo)
label.pack()
root.mainloop()

You'll have to forgive me for removing your class but I've never personally worked with classes in python before. However I seem to have you code working to some degree.
import tkinter
from tkinter import *
def playGame():
frame.quit
gameMenu()
def gameMenu():
b = mainMenu(root)
topFrame = Frame(root)
topFrame.pack()
bottomFrame = Frame(root)
bottomFrame.pack(side = BOTTOM)
photo = PhotoImage(file = "piano.png")
label = Label(root, image = photo)
label.pack()
root=Tk()
frame = Frame(root)
frame.pack()
quitButton = Button(frame, text = "Quit", command = frame.quit)
quitButton.pack(side = LEFT)
proceedButton = Button(frame, text = "Play", command = playGame)
proceedButton.pack(side = LEFT)
root.mainloop()
The main problem you had was that you were using both root and master. When declaring the main window in tkinter you normally use either root = Tk() or master = Tk() either one is acceptable, personally I use master. This variable contains the main window that everything else is placed into. You also hadn't put Tk() into any variable, meaning that when you hit root.mainloop() there was nothing to enter the main loop, this was because you were trying to declare root = Tk() inside gameMenu, which wasn't getting called in your program.
If you want to open windows within tkinter it's probably easier to write something like this:
from tkinter import *
master = Tk() #Declaring of main window
def ProceedButtonCommand(mainframe, master): #Command to attach to proceed button
mainframe.destroy()
DrawSecondScreen(master) #This line is what lets the command tied to the button call up the second screen
def QuitButtonCommand(master):
master.destroy()
def DrawFirstScreen(master):
mainframe = Frame(master) #This is a way to semi-cheat when drawing new screens, destroying a frame below master frame clears everything from the screen without having to redraw the window, giving the illusion of one seamless transition
ProceedButton = Button(mainframe, text="Proceed", command=lambda: ProceedButtonCommand(mainframe, master)) #Lambda just allows you to pass variables with the command
QuitButton = Button(mainframe, text = "Quit", command=lambda: QuitButtonCommand(master))
mainframe.pack()
ProceedButton.pack()
QuitButton.pack()
def DrawSecondScreen(master):
mainframe = Frame(master)
Label1 = Label(mainframe, text="Temp")
mainframe.pack()
Label1.pack()
DrawFirstScreen(master)
master.mainloop() #The mainloop handles all the events that occur in a tkinter window, from button pressing to the commands that a button runs, very important
This little script just draws a screen with two buttons, one draws a new screen with the text "temp" on it and the other button closes the master window.
In the future it's probably a better idea to ask a friend who is experienced in programming to help with this kind of stuff. Get talking on some computing forums, I'm sure you'll find a group of sharing and fixing code quickly.