Develop Reference

tkinter: Using same frame but having different command button?

Pardon me for my bad grammar or explanation, since I didn't know how to explain this properly.
I try to build some gui that could switch between frame, using script from this as base Switch between two frames in tkinter.
In this case, I will have a few frame that had similar design, but different function when the button is pressed. For example, I have 2 frames that have similar 2 entries and 1 button, but the button do different command (where at sub01 frame it will multiply and at sub02 frame will divide)
This is my code:
class SampleApp(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
container = tk.Frame(self)
container.grid(row=1,columnspan=4,sticky='nsew')
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in (sub01, sub02):
page_name = F.__name__
frame = F(parent=container, controller=self)
self.frames[page_name] = frame
frame.grid(row=1,sticky="nsew")
self.choices = {'sub01','sub02'}
self.tkvar = tk.StringVar()
self.tkvar.set('sub01')
self.popMenu = tk.OptionMenu(self,self.tkvar,*self.choices)
self.popMenu.grid(row=0)
self.show_frame()
self.button1 = tk.Button(self, text="Go to Layer",command=lambda: self.show_frame())
self.button1.grid(row=0, column=1)
def show_frame(self):
'''Show a frame for the given page name'''
page_name = self.tkvar.get()
frame = self.frames[page_name]
frame.tkraise()
class sub01(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
label = tk.Label(self, text="This SubLayer 1")
label.grid(row=0)
self.entries=[]
i = 0
while i < 2:
self.entries.append(tk.Entry(self,width=10))
self.entries[i].grid(row=i+1,columnspan=2,sticky='we')
i += 1
self.btn = tk.Button(self,text="multiply", command=lambda : self.multiply())
self.btn.grid(row=i+1, columnspan=2,sticky='we')
def multiply(self):
pass
class sub02(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
label = tk.Label(self, text="This SubLayer 2")
label.grid(row=0)
self.entries=[]
i = 0
while i < 2:
self.entries.append(tk.Entry(self,width=10))
self.entries[i].grid(row=i+1,columnspan=2,sticky='w')
i += 1
self.btn = tk.Button(self,text="divide",command=lambda : self.divide())
self.btn.grid(row=i+1, columnspan=2,sticky='we')
def divide(self):
pass
if __name__ == "__main__":
app = SampleApp()
app.mainloop()
This code itself works, but when I need to create more of these frames, it becomes inconvenient. How could I make this code simpler? Like having that similar frame as a class, and the button as other class that do differ behaviour depend of the layer shown.
Thank you in advance

The canonical way to do this sort of thing is to create a class hierarchy for your Page classes and put common functionality in the base classes and derive subclasses from them that specify the behavior that differs between them. Below is how you could do that with the sample code in your question.
Since the things that are different between them are:
The text displayed on the Label.
The text displayed on the Button.
The code in that's execute when the Button is clicked.
This means the derived classes only need to know what code to run in a generically named btn_func() method and what the text to displayed on the two widgets. The code below illustrates how to do that.
Note that I've changed the spelling of your class names to conform to the naming conventions describe in PEP 8 - Style Guide for Python Code.
import Tkinter as tk
class SampleApp(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
container = tk.Frame(self)
container.grid(row=1,columnspan=4,sticky='nsew')
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in (Sub01, Sub02):
page_name = F.__name__
frame = F(parent=container, controller=self)
self.frames[page_name] = frame
frame.grid(row=1,sticky="nsew")
self.choices = {'Sub01','Sub02'}
self.tkvar = tk.StringVar()
self.tkvar.set('Sub01')
self.popMenu = tk.OptionMenu(self,self.tkvar,*self.choices)
self.popMenu.grid(row=0)
self.show_frame()
self.button1 = tk.Button(self, text="Go to Layer",command=lambda: self.show_frame())
self.button1.grid(row=0, column=1)
def show_frame(self):
'''Show a frame for the given page name'''
page_name = self.tkvar.get()
frame = self.frames[page_name]
frame.tkraise()
class BaseSubLayer(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
label = tk.Label(self, text=self.lbl_text)
label.grid(row=0)
self.entries=[]
i = 0
while i < 2:
self.entries.append(tk.Entry(self,width=10))
self.entries[i].grid(row=i+1,columnspan=2,sticky='we')
i += 1
self.btn = tk.Button(self,text=self.btn_func_name, command=self.btn_func)
self.btn.grid(row=i+1, columnspan=2,sticky='we')
def btn_func(self):
raise NotImplementedError
class Sub01(BaseSubLayer):
lbl_text = 'This SubLayer 1'
btn_func_name = 'multiply'
def btn_func(self):
print('Running multiply() method.')
class Sub02(BaseSubLayer):
lbl_text = 'This SubLayer 2'
btn_func_name = 'divide'
def btn_func(self):
print('Running divide() method.')
if __name__ == "__main__":
app = SampleApp()
app.mainloop()

How do you change the variable in a function from a different class and call it back?

I am making a game with levels and in each level, I will need to be using different operators and/or different ranges. My problem is that I don't know how to change the variables in a function from a different class. I would like to do this so I don't need to copy and paste my code making it lengthy. I'd like to use self.Answer and self.strQuestion for mulitple scope.
The code below is just to make the classes functional.
from tkinter import *
import tkinter as tk
import random
from Tkinter import messagebox
class BattleMaths(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)
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in (StartPage, levelone, leveltwo):
frame = F(container, self)
self.frames[F] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame(StartPage)
def show_frame(self, cont):
frame = self.frames[cont]
frame.tkraise()
class StartPage(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
lvl1_button = Button(self, text="LEVEL 1", command=lambda: controller.show_frame(levelone))
lvl1_button.place(relx=0.5, rely=0.5, anchor='center')
I want to put the questions def into class leveltwo while changing it to self.Answer = int(numOne) * int(numTwo) and self.strQuestion = "{} x {}".format(str(numOne), str(numTwo))
class levelone(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
def widgets(self):
#widgets here
def question(self):
self.UserAnswer = ''
numOne = random.randrange(1,10)
numTwo = random.randrange(1,10)
self.Answer = int(numOne) + int(numTwo) #change this
self.strQuestion = "{} + {}".format(str(numOne), str(numTwo)) #and change this
def answer(self):
#answer checker
class leveltwo(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
#question def here
root = BattleMaths()
root.title("Battle Maths")
root.geometry("400x250")
root.resizable(0,0)
root.mainloop()

Create the variables you want in the main class (BattleMaths), then you can alter them in the child classes via controller.my_variable.
Example: self.Answer created in BattleMaths and accessed in levelone via controller.Answer

Python - Global not working as expected

I'm currently working on a tkinter project. The code is shown below:
import tkinter as tk
from tkinter import font as tkfont
background_colour = "#F0F0F0"
class Application(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.title("CCNA Command Learner")
self.geometry("500x500")
self.iconbitmap("favicon.ico")
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 (IntroPage, MainPage):
page_name = F.__name__
frame = F(parent=container, controller=self)
self.frames[page_name] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame("IntroPage")
def show_frame(self, page_name):
frame = self.frames[page_name]
frame.tkraise()
class IntroPage(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
self.image = tk.PhotoImage(file="IntroImage.gif")
self.head_img = tk.Label(self, image=self.image, background=background_colour)
self.head_img.pack()
self.label = tk.Label(self, bg=background_colour,
text="\nLearn essential commands for the CCNA exam\n\nPlease enter your name")
self.label.pack()
self.head_entry = tk.Entry(self)
self.head_entry.pack()
self.submit = tk.Button(self, text="Submit", command=self.submit_button)
self.submit.pack()
def submit_button(self):
global var_username
self.controller.show_frame("MainPage")
var_username = self.head_entry.get()
class MainPage(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
self.controller = controller
self.introduction = tk.Label(self, text="Hello" + var_username)
self.introduction.pack()
if __name__ == "__main__":
app = Application()
app.mainloop()
My problem is that in the submit_button method of my IntroPage class, I am trying to set a global variable so that my MainPage class can then access it. However, despite declaring it and setting it, I am still getting a NameError when accessing it in my MainPage class?

That's correct, as you seem to use global incorrectly. It can make existing variable out of your scope visible and available for modification, like this:
a = 'test'
def f():
global a
a = 'edited'
f()
print(a)
Output:
>>> edited
You don't seem to declare variable with this name, hence the NameError. And again - global is not for creating global variables, it is for making them visible.
By the way, think twice before using globals in python, that usually indicates huge design problems. It's surely possible to refactor your code in a way that you won't need global.

You simply need create it before MainPage in call stack.
Create it outside the IntroPage class, and initializing can stay where it is.

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()))

Import data from another class python

I need to access the temperature variable from Monitor Class and print on Graph Class. How can I do that? Please see code below which should compile.
from tkinter import *
import tkinter as tk
import time
class ScientificPumpGui(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.container = tk.Frame(self)
self.container.pack(side="top", fill="both", expand=True)
self.container.grid_rowconfigure(0, weight=1)
self.container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in (MonitorPage, GraphPage):
frame = F(self.container)
self.frames[F] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame(MonitorPage)
self.create_buttons()
def show_frame(self, cont):
frame = self.frames[cont]
frame.tkraise()
def exit_app(self):
exit()
def create_buttons(self):
main_b_height = 2
main_b_width = 20
page_button_pady = 10
self.page_button_main_toolbar = tk.Frame(self, borderwidth=1)
self.page_button_main_toolbar.pack(side=TOP, anchor=CENTER, fill=X)
self.page_button_toolbar = tk.Frame(self.page_button_main_toolbar, borderwidth=1)
self.page_button_toolbar.pack(side=TOP, anchor=CENTER)
self.monitor_page_button = Button(self.page_button_toolbar, text="Monitor Page", width=main_b_width, height=main_b_height, command=lambda: self.show_frame(MonitorPage))
self.monitor_page_button.pack(side=LEFT, anchor=CENTER, pady=page_button_pady)
self.graph_page_button = Button(self.page_button_toolbar, text="Graph Page", width=main_b_width, height=main_b_height, command=lambda: self.show_frame(GraphPage))
self.graph_page_button.pack(side=LEFT, anchor=CENTER, pady=page_button_pady)
self.exit_app_button = Button(self.page_button_toolbar, text="Exit App", width=main_b_width, height=main_b_height, command=lambda: ScientificPumpGui.exit_app(0))
self.exit_app_button.pack(side=LEFT, anchor=CENTER, pady=page_button_pady)
class MonitorPage(tk.Frame):
def __init__(self, parent):
tk.Frame.__init__(self, parent)
self.monitor_data_counter = 0
self.page_label = tk.Label(self, text="Monitor Page")
self.page_label.pack(pady=10, padx=10)
def value_function(self):
self.temperature = 100
class GraphPage(tk.Frame):
def __init__(self, parent):
tk.Frame.__init__(self, parent)
label = tk.Label(self, text="Graph Page!")
label.pack(pady=5, padx=10)
app = ScientificPumpGui()
app.mainloop()
When I tried to read temperature using:
monitor_page=MonitorPage(ScientificPumpGui())
print(str(monitor_page.temperature))
monitor_page.mainloop()
The error I get is:
AttributeError: 'MonitorPage' object has no attribute 'temperature'

Your MonitorPage class does not declaretemperature in the constructor function, but in value_function.
You can either declare temperature inside __init__ function, or call value_function before reading temperature.

You get this error because the member temperature is initialized in value_function method, which is not getting called.
As you didn't called to this method, the member temperature is not initialized and therefore you get the error.
In order to prevent this error, you should define the member temperature in your __init__ method with a default value.
You also can fix it by calling to the value_function method in order to initialize the member temperature.