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how to call a function of class based tkinter Frame from another class based frame [duplicate]

This question already has answers here:
Calling functions from a Tkinter Frame to another
(2 answers)
Closed 1 year ago.
I have a Tkinter application that has multiple class based frames and I would like to call a function which is in tkinter Frame from another frame/class.
For example, my frames are like this:
class_B(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
def Update_class_b():
label = tk.Label(class_B, text=f"Welcome", font=LARGEFONT)
label.grid(row=1, column=0)
# wigdgets
button = tk.Button(self, text="START_TRIP", command=lambda: controller.show_frame(D_file.D_class)
#i am using this controller to navigate between those pages
# packing/grid
button.grid(row=2, column=0, padx=10, pady=10)
Now, I would like to call the function update_class_b from another class base frame. How can I do that right now I am passing class_B in label widget while making it as you can see and directly calling it in class_A, but it is not working. Please if anyone could help me regarding this.
Also, I would like to call this update_class_b function from inside another class based frame like while pressing a button in Class_A this function should be triger
class A would be like
class class_A(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
def do_something_in_class_B():
#this should trigger Update_class_b function in class_B
button = tk.Button(self, text="DO SOMETHING IN CLASS B", command=do_something_in_class_B).pack()
controller class
class tkinterApp(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
container = tk.Frame(self)
container.pack(side="top", fill="both", expand=True)
self.frames = {}
self.attributes('-fullscreen', True)
for F in (file_A.Class_A,file_B.class_B):
frame = F(container, self)
self.frames[F] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame(startPage.StartPage)
def show_frame(self, cont):
frame = self.frames[cont]
frame.tkraise()
if __name__ == "__main__":
app = tkinterApp()
app.mainloop()

Assuming you have your frames stored in a dictionary in the controller frame:
func = controller.frames[class_B].update_class_b
button = tk.Button(self, text="START_TRIP", command=func)
button.grid(row=2, column=0, padx=10, pady=10)
We'd have to see a MCVE to give a specific answer.

Segmentation fault: 11 - tkinter python

Segmentation fault: 11 - not sure what it means, why it has happened. I thought it was an issue with Python on my machine by all other files run fine. I have, of course, tried restarting and re-installing Python but didn't help.
I'm just trying to implement frame switching via a menu bar with tkinter.
Any help greatly appreciated.
# import tkinter modules
from tkinter import *
from tkinter import ttk
import tkinter.font as tkFont
from PIL import ImageTk, Image
from tkcalendar import *
# import modules for restart functionality
import os
import sys
import time
# define self
class tkinterApp(Tk):
def __init__(self,*args, **kwargs):
Tk.__init__(self, *args, **kwargs)
# creating a container
container = Frame(self)
container.pack(side = "top", fill = "both", expand = True)
container.grid_rowconfigure(0, weight = 1)
container.grid_columnconfigure(0, weight = 1)
# initialising frames to an empty array
self.frames = {}
menu_bar = Menu(container)
menu_bar.add_cascade(label="Main Menu", menu=menu_bar)
menu_bar.add_command(label="Welcome page", command=lambda: self.show_frame(welcome_frame))
menu_bar.add_command(label="Book a vehicle", command=lambda: self.show_frame(booking_frame))
menu_bar.add_command(label="Register as new user", command=lambda: self.show_frame(register_frame))
Tk.config(self, menu=menu_bar)
for F in (welcome_frame, register_frame, booking_frame):
frame = F(container, self)
self.frames[F] = frame
frame.grid(row = 0, column = 0, sticky = "nsew")
self.show_frame(welcome_frame)
def show_frame(self, cont):
frame = self.frames[cont]
frame.tkraise()
class welcome_frame(Frame):
def __init__(self, parent, controller):
Frame.__init__(self, parent)
# welcome_frame = Frame(self, width=1000, height=800)
# welcome_frame.grid()
welcome = Label(welcome_frame, text="Hello, please use the menu above to navigate the interface")
welcome.grid(row=0, column=4, padx=10, pady=10)
class register_frame(Frame):
def __init__(self, parent, controller):
Frame.__init__(self, parent)
welcome = Label(self, text="New user - enter your details below to use the Collyer's car park.")
welcome.grid(row=0, column=4, padx=10, pady=10)
class booking_frame(Frame):
def __init__(self, parent, controller):
Frame.__init__(self, parent)
app = tkinterApp()
app.geometry("1000x800")
app.mainloop()

You are trying to make a cascade menu where the cascaded menu is the same menu:
menu_bar.add_cascade(label="Main Menu", menu=menu_bar)
The menu option needs to point to a new menu menu.
main_menu = Menu(menu_bar)
menu_bar.add_cascade(label="Main Menu", menu=main_menu)
I'm guessing you also want to put the menu commands on that menu, too
main_menu.add_command(label="Book a vehicle", command=lambda: self.show_frame(booking_frame))
main_menu.add_command(label="Register as new user", command=lambda: self.show_frame(register_frame))
Unrelated to the question, this code is also wrong:
welcome = Label(welcome_frame, text="Hello, please use the menu above to navigate the interface")
You are trying to use a class as the parent/master of the Label widget. You can't do that. The first parameter needs to be a widget. In this case, it should be self.
You also need to make sure that show_frame is indented the same as the __init__ method of the tkinterApp class.

Why aren't radiobuttons working in a Tkinter window with multiple frames?

I copied Python code to create a Tkinter window with multiple frames. I put many kinds of widgets into it with no problem but when I add radiobuttons, those act funny, although they work fine in a regular window (without multiple pages). Whether I set the value or not, none of the radiobuttons are selected. What's worse, if I just pass the mouse pointer over a radiobutton, it looks like it gets selected although I didn't click it. If I pass the mouse pointer over both radiobuttons, they BOTH look selected, violating the one-of-many-selections rule of radiobuttons.
I should add that I tried this with a pack manager and with a grid manager. The results are the same.
Here's a stripped-down version of my code:
import tkinter as tk
class MainWindow(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
# Set the title of the main window.
self.title('Multi-frame window')
# Set the size of the main window to 300x300 pixels.
self.geometry('300x100')
# This container contains all the pages.
container = tk.Frame(self)
container.grid(row=1, column=1)
self.frames = {} # These are pages to which we want to navigate.
# For each page...
for F in (StartPage, PageOne):
# ...create the page...
frame = F(container, self)
# ...store it in a frame...
self.frames[F] = frame
# ..and position the page in the container.
frame.grid(row=0, column=0, sticky='nsew')
# The first page is StartPage.
self.show_frame(StartPage)
def show_frame(self, name):
frame = self.frames[name]
frame.tkraise()
class StartPage(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
label = tk.Label(self, text='Start Page')
label.grid(row=1, column=1)
# When the user clicks on this button, call the
# show_frame method to make PageOne appear.
button1 = tk.Button(self, text='Visit Page 1',
command=lambda : controller.show_frame(PageOne))
button1.grid(row=2, column=1)
class PageOne(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
# When the user clicks on this button, call the
# show_frame method to make StartPage appear.
button1 = tk.Button(self, text='Back to Start',
command=lambda : controller.show_frame(StartPage))
button1.grid(row=1, column=1)
options_label = tk.Label(self, text='Choose an option: ')
options_label.grid(row=2, column=1)
options_value = tk.IntVar()
first_option = tk.Radiobutton( self , text = 'Option 1' ,
variable = options_value , value = 1 )
second_option = tk.Radiobutton( self , text = 'Option 2' ,
variable = options_value , value = 2 )
first_option.grid(row=2, column=2)
second_option.grid(row=2, column=3)
options_value.set(1)
if __name__ == '__main__':
app = MainWindow()
app.mainloop()

The problem is that options_value is a local value that gets destroyed when __init__ finishes.
You need to save a reference to it, such as self.options_value.

Variables from other classes in Tkinter [duplicate]

This is a shortened example of a longer application where I have multiple pages of widgets collecting information input by the user. The MyApp instantiates each page as a class. In the example, PageTwo would like to print the value of the StringVar which stores the data from an Entry widget in PageOne.
How do I do that? Every attempt I've tried ends up with one exception or another.
from tkinter import *
from tkinter import ttk
class MyApp(Tk):
def __init__(self):
Tk.__init__(self)
container = ttk.Frame(self)
container.pack(side="top", fill="both", expand = True)
self.frames = {}
for F in (PageOne, PageTwo):
frame = F(container, self)
self.frames[F] = frame
frame.grid(row=0, column=0, sticky = NSEW)
self.show_frame(PageOne)
def show_frame(self, cont):
frame = self.frames[cont]
frame.tkraise()
class PageOne(ttk.Frame):
def __init__(self, parent, controller):
ttk.Frame.__init__(self, parent)
ttk.Label(self, text='PageOne').grid(padx=(20,20), pady=(20,20))
self.make_widget(controller)
def make_widget(self, controller):
self.some_input = StringVar
self.some_entry = ttk.Entry(self, textvariable=self.some_input, width=8)
self.some_entry.grid()
button1 = ttk.Button(self, text='Next Page',
command=lambda: controller.show_frame(PageTwo))
button1.grid()
class PageTwo(ttk.Frame):
def __init__(self, parent, controller):
ttk.Frame.__init__(self, parent)
ttk.Label(self, text='PageTwo').grid(padx=(20,20), pady=(20,20))
button1 = ttk.Button(self, text='Previous Page',
command=lambda: controller.show_frame(PageOne))
button1.grid()
button2 = ttk.Button(self, text='press to print', command=self.print_it)
button2.grid()
def print_it(self):
print ('The value stored in StartPage some_entry = ')#What do I put here
#to print the value of some_input from PageOne
app = MyApp()
app.title('Multi-Page Test App')
app.mainloop()

Leveraging your controller
Given that you already have the concept of a controller in place (even though you aren't using it), you can use it to communicate between pages. The first step is to save a reference to the controller in each page:
class PageOne(ttk.Frame):
def __init__(self, parent, controller):
self.controller = controller
...
class PageTwo(ttk.Frame):
def __init__(self, parent, controller):
self.controller = controller
...
Next, add a method to the controller which will return a page when given the class name or some other identifying attribute. In your case, since your pages don't have any internal name, you can just use the class name:
class MyApp(Tk):
...
def get_page(self, classname):
'''Returns an instance of a page given it's class name as a string'''
for page in self.frames.values():
if str(page.__class__.__name__) == classname:
return page
return None
note: the above implementation is based on the code in the question. The code in the question has it's origin in another answer here on stackoverflow. This code differs from the original code slightly in how it manages the pages in the controller. This uses the class reference as a key, the original answer uses the class name.
With that in place, any page can get a reference to any other page by calling that function. Then, with a reference to the page, you can access the public members of that page:
class PageTwo(ttk.Frame):
...
def print_it(self):
page_one = self.controller.get_page("PageOne")
value = page_one.some_entry.get()
print ('The value stored in StartPage some_entry = %s' % value)
Storing data in the controller
Directly accessing one page from another is not the only solution. The downside is that your pages are tightly coupled. It would be hard to make a change in one page without having to also make a corresponding change in one or more other classes.
If your pages all are designed to work together to define a single set of data, it might be wise to have that data stored in the controller, so that any given page does not need to know the internal design of the other pages. The pages are free to implement the widgets however they want, without worrying about which other pages might access those widgets.
You could, for example, have a dictionary (or database) in the controller, and each page is responsible for updating that dictionary with it's subset of data. Then, at any time you can just ask the controller for the data. In effect, the page is signing a contract, promising to keep it's subset of the global data up to date with what is in the GUI. As long as you maintain the contract, you can do whatever you want in the implementation of the page.
To do that, the controller would create the data structure before creating the pages. Since we're using tkinter, that data structure could be made up of instances of StringVar or any of the other *Var classes. It doesn't have to be, but it's convenient and easy in this simple example:
class MyApp(Tk):
def __init__(self):
...
self.app_data = {"name": StringVar(),
"address": StringVar(),
...
}
Next, you modify each page to reference the controller when creating the widgets:
class PageOne(ttk.Frame):
def __init__(self, parent, controller):
self.controller=controller
...
self.some_entry = ttk.Entry(self,
textvariable=self.controller.app_data["name"], ...)
Finally, you then access the data from the controller rather than from the page. You can throw away get_page, and print the value like this:
def print_it(self):
value = self.controller.app_data["address"].get()
...

I faced a challenge in knowing where to place the print_it function.
i added the following to make it work though I don't really understand why they are used.
def show_frame(self,page_name):
...
frame.update()
frame.event_generate("<<show_frame>>")
and added the show_frame.bind
class PageTwo(tk.Frame):
def __init__(....):
....
self.bind("<<show_frame>>", self.print_it)
...
def print_it(self,event):
...
Without the above additions, when the mainloop is executed,
Page_Two[frame[print_it()]]
the print_it function executes before PageTwo is made Visible.
try:
import tkinter as tk # python3
from tkinter import font as tkfont
except ImportError:
import Tkinter as tk #python2
import tkFont as tkfont
class SampleApp(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.title_font = tkfont.Font(family="Helvetica", size=18, weight="bold", slant="italic")
# data Dictionary
self.app_data = {"name": tk.StringVar(),
"address": tk.StringVar()}
# the container is where we'll stack a bunch of frames
# on top of each other, then the one we want visible
# will be raised above the others.
container = tk.Frame(self)
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 (StartPage, PageOne, PageTwo):
page_name = F.__name__
frame = F(parent=container, controller=self)
self.frames[page_name] = frame
# put all of the pages in the same location;
# the one on the top of the stacking order
# will be the one that is visible
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame("StartPage")
def show_frame(self, page_name):
''' Show a frame for the given page name '''
frame = self.frames[page_name]
frame.tkraise()
frame.update()
frame.event_generate("<<show_frame>>")
class StartPage(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
label = tk.Label(self, text="this is the start page", font=self.controller.title_font)
label.pack(side="top", fill="x", pady=10)
# Update the Name value only
self.entry1 = tk.Entry(self,text="Entry", textvariable=self.controller.app_data["name"])
self.entry1.pack()
button1 = tk.Button(self, text="go to page one", command = lambda: self.controller.show_frame("PageOne")).pack()
button2 = tk.Button(self, text="Go to page Two", command = lambda: self.controller.show_frame("PageTwo")).pack()
class PageOne(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
label = tk.Label(self, text="This is page 1", font=self.controller.title_font)
label.pack(side="top", fill="x", pady=10)
# Update the Address value only
self.entry1 = tk.Entry(self,text="Entry", textvariable=self.controller.app_data["address"])
self.entry1.pack()
button = tk.Button(self, text="Go to the start page", command=lambda: self.controller.show_frame("StartPage"))
button.pack()
class PageTwo(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
# Bind the print_it() function to this Frame so that when the Frame becomes visible print_it() is called.
self.bind("<<show_frame>>", self.print_it)
label = tk.Label(self, text="This is page 2", font=self.controller.title_font)
label.pack(side="top", fill="x", pady=10)
button = tk.Button(self, text="Go to the start page",
command=lambda: self.controller.show_frame("StartPage"))
button.pack()
def print_it(self,event):
StartPage_value = self.controller.app_data["name"].get()
print(f"The value set from StartPage is {StartPage_value}")
PageOne_value= self.controller.app_data["address"].get()
print(f"The value set from StartPage is {PageOne_value}")
if __name__ == "__main__":
app = SampleApp()
app.mainloop()

Calling a widget from another class to change its properties in tKinter

I have made a function in the main constructor of my tKinter app which updates certain properties of widgets e.g. their text across multiple frames. What I'm trying to do is change widgets in multiple frames at the same time while in a controller frame.
def update_widgets(self, frame_list, widget_name, criteria, output):
for i in frame_list:
i.widget_name.config(criteria=output)
# update_widgets(self, [Main, AnalysisSection], text_label, text, "foo")
# would result in Main.text_label_config(text="foo") and
# AnalysisSection.text_label_config(text="foo") ideally.
However with this code, I'm encountering two problems. Firstly, I'm getting an attribute error stating that both frames don't have the attribute widget_name. Secondly, when I tried to refer to the widget names with the self prefix, both frames say they don't have the attribute self. Is there a way to fix this?
Full program below:
import tkinter as tk
class Root(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.frames = {}
container = tk.Frame(self)
container.pack(side="bottom", expand=True)#fill="both", expand=True)
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
for X in (A, B):
frame=X(container, self)
self.frames[X]=frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame(A)
def show_frame(self, page):
frame = self.frames[page]
frame.tkraise()
def update_widgets(self, frame_list, widget_name, criteria, output):
for i in frame_list:
frame = self.frames[i]
widget = getattr(frame, widget_name)
widget[criteria] = output
class A(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
self.text = 'hello'
self.classLabel = tk.Label(self, text="Frame A")
self.classLabel.pack(side=tk.TOP)
# trying to change this widget
self.wordLabel = tk.Label(self, text="None")
self.wordLabel.pack(side=tk.TOP)
self.changeTextLabel = tk.Label(self, text="Change text above across both frames").pack(side=tk.TOP)
self.changeTextEntry = tk.Entry(self, bg='pink')
self.changeTextEntry.pack(side=tk.TOP)
self.changeFrameButton = tk.Button(text="Change to Frame B", command=lambda: self.controller.show_frame(B))
self.changeFrameButton.pack(side=tk.TOP, fill=tk.X)
self.changeTextEntryButton = tk.Button(self, text="ENTER", width=5, command=lambda: self.controller.update_widgets([A, B], 'self.wordLabel', 'text', self.changeTextEntry.get()))
self.changeTextEntryButton.pack(side=tk.TOP, fill=tk.X)
### calling this function outside of the button; this is already
### called within a function in my project.
x = self.controller.update_widgets([A, B], 'wordLabel', 'text', '*initial change*')
class B(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
self.text = 'hello'
self.classLabel = tk.Label(self, text="Frame B")
self.classLabel.pack(side=tk.TOP)
# trying to change this widget
self.wordLabel = tk.Label(self, text="None")
self.wordLabel.pack(side=tk.TOP)
self.changeTextLabel = tk.Label(self, text="Change text above across both frames").pack(side=tk.TOP)
self.changeTextEntry = tk.Entry(self, bg='light yellow').pack(side=tk.TOP)
self.changeFrameButton = tk.Button(text="Change to Frame A", command=lambda: self.controller.show_frame(A))
self.changeFrameButton.pack(side=tk.TOP, fill=tk.X)
self.changeTextEntryButton = tk.Button(self, text="ENTER", width=5, command=lambda: self.controller.update_widgets([A, B], 'self.wordLabel', 'text', self.changeTextEntry.get()))
self.changeTextEntryButton.pack(side=tk.TOP, fill=tk.X)
if __name__ == '__main__':
app = Root()

The problem in your code is that you're trying to get an attribute of a class rather than an instance of a class. You need to convert i to the actual instance of that class. You have the additional problem that you're passing 'self.wordLabel' rather than just 'wordLabel'.
A simple fix is to look up the instance in self.frames
def update_widgets(self, frame_list, widget_name, criteria, output):
for i in frame_list:
frame = self.frames[i]
label = getattr(frame, widget_name)
label[criteria] = output
You also need to change the button command to look like this:
self.changeTextEntryButton = tk.Button(... command=lambda: self.controller.update_widgets([A,B], 'wordLabel', 'text', self.changeTextEntry.get()))
If you intend for update_widgets to always update all of the page classes, there's no reason to pass the list of frame classes in. Instead, you can just iterate over the known classes:
def update_widgets(self, widget_name, criteria, output):
for frame in self.frames.values():
label = getattr(frame, 'classLabel')
label[criteria] = output
You would then need to modify your buttons to remove the list of frame classes:
self.changeTextEntryButton = tk.Button(..., command=lambda: self.controller.update_widgets('wordLabel', 'text', self.changeTextEntry.get()))