Develop Reference

How to create a subclass of ttk.Button correctly (class function doesnt work)?

I want to create Buttons with a text and define a function that prints me the text on the monitor when i press the button.
Everything works well without classes:
from tkinter import *
from tkinter import ttk
def PressButton():
print(FirstButton.cget('text'))
root = Tk()
root.title("Simple Calculator")
ButtonsFrame = ttk.Frame(root,relief= "groove").grid()
FirstButton=ttk.Button(ButtonsFrame, text=1, command= PressButton)
FirstButton.grid()
root.mainloop()
"1" is printed on the monitor when I press FirstButton.
Because I want to have a lot of Buttons, I created a class MyButton with the parent ttk.Button:
from tkinter import *
from tkinter import ttk
class MyButton(ttk.Button):
def __init__(self, text):
self.text=text
super().__init__()
self.Button=ttk.Button(ButtonsFrame, text=self.text, command=self.PressButton)
def PressButton(self):
print(self.Button.cget('text'))
root = Tk()
root.title("Simple Calculator")
ButtonsFrame = ttk.Frame(root,relief= "groove").grid()
FirstButton=MyButton(1)
FirstButton.grid()
root.mainloop()
Here a button is created but without text at all.
I found out that if I change the super().__init__() to super()._init__(text=self.text) then I get a Button with the right text but the PressButton command doesnt work. I tried diffent things with *args aswell but had no success.
What am I doing wrong? I would appreciate any help.

The main problem is that you're not specifying the parent widget for the parent in the constructor.
Here's corrected version of code:
from tkinter import *
from tkinter import ttk
class MyButton(ttk.Button):
def __init__(self, parent, text):
self.text=text
super().__init__(parent, text=self.text, command=self.PressButton)
def PressButton(self):
print(self.cget('text'))
root = Tk()
root.title("Simple Calculator")
ButtonsFrame = ttk.Frame(root,relief= "groove").grid()
FirstButton=MyButton(ButtonsFrame, 1)
FirstButton.grid()
root.mainloop()
You could've also swapped super(). with this:
super(MyButton,self).__init__(parent, text=self.text,command=self.PressButton)
Which is equal to super().__init__(parent, text=self.text, command=self.PressButton)
You can read more about it here:
https://docs.python.org/3/library/functions.html#super

Integrating tkinter event loop in ipython notebook

With a simple tkinter gui like this:
import tkinter as tk
class Application(tk.Frame):
def __init__(self, master=None):
tk.Frame.__init__(self, master)
self.grid()
self.createWidgets()
def printHello(self):
print("Hello")
def createWidgets(self):
self.quitButton = tk.Button(self, text='Quit',
command=self.quit)
self.quitButton.grid(row=1,column=0)
self.printButton = tk.Button(self, text='Print',command=lambda: self.printHello())
self.printButton.grid(row=1,column=1)
app = Application()
app.master.title('Sample application')
app.mainloop()
I am trying to follow this documentation to connect the event loop with the ipython notebook's kernel: https://ipython.org/ipython-doc/3/config/eventloops.html
But I can't quite seem to grasp how it works especially: #register_integration('tk')
How can I exactly connect the event loops? And if I do, what can I do with a connected event loop?

How to get the text out of a scrolledtext widget?

I am new to the tkinter python module. I try to do a project. I learned something new about the menus and I'm trying to make a little UI project that allows the user to write something in a scrolled text widget and then save it (using the sys module).
I've already tried some things that worked at buttons. For example .get() but it didn't work. I also tried the ["text"] method.
import tkinter, sys
root = tkinter.Tk()
class saveProject:
def __init__(self, master):
self.master = master
self.textFrame = tkinter.scrolledtext.ScrolledText(self.master, width=100, bd=10, relief="raised")
self.textFrame.pack()
def save(self):
#self.saveText = self.textFrame.get()
self.saveText = self.textFrame["text"]
project = saveProject(root)
root.mainloop()
The problem is, as I already said, I don't know how to get the text out of a tkinter.scrolledtext.ScrolledText widget.

So, out of curiosity I tried what described here (same link in my comment to the OP question). It works also for the scrolledtext.
import tkinter, sys
from tkinter import scrolledtext
root = tkinter.Tk()
class saveProject:
def __init__(self, master):
self.master = master
self.textFrame = scrolledtext.ScrolledText(self.master, width=100, bd=10, relief="raised")
self.textFrame.pack()
self.saveb = tkinter.Button(self.master, text="Save", command= lambda : self.save())
self.saveb.pack()
def save(self):
cur_inp = self.textFrame.get("1.0", tkinter.END)
fl = open("output.txt", "w")
fl.write(cur_inp)
project = saveProject(root)
root.mainloop()
I've added a save button at the bottom of the ScrolledText widget. The widget content is saved inside the output.txt area.

help(ScrolledText) indicates it's a subclass of the tkinter.Text widget, which apparently means that the way to get the text from it is the same — via its get() method using "Text widget indices" (here's some documentation about them).
Below is an example that gets all of the text in the widget (I added a Save text Button to test the save() method):
import sys
import tkinter as tk
from tkinter.scrolledtext import ScrolledText
class SaveProject:
def __init__(self, master):
self.master = master
self.textFrame = ScrolledText(self.master, width=100, bd=10, relief="raised")
self.textFrame.pack()
# Added for testing.
self.save_btn = tk.Button(self.master, text='Save text', command=self.save)
self.save_btn.pack()
def save(self):
self.saveText = self.textFrame.get('1.0', tk.END) # Get all text in widget.
print('self.saveText:', self.saveText)
root = tk.Tk()
project = SaveProject(root)
root.mainloop()

Tkinter newly created button does not execute command

A script should open an application with two buttons visible. When Hello button is pressed a new button is gridded into the row number 1 and Hello button to be deactivated. When this new button is pressed it should delete itself off the grid and reactivate hello button but it does not do it.
Please check the video to see it in action.
Code edited to comment suggestion
from tkinter import *
class Application(Frame):
def __init__(self, master=None):
self.master = master
self.master.geometry('300x100+10+10')
Frame.__init__(self, master)
self.pack()
self.createWidgets()
def new_button(self):
print("enable_b")
self.hi_there.config(state=ACTIVE)
self.new_button.grid_remove()
def say_hi(self):
print("hi there, everyone!")
self.new_button = Button(self)
self.new_button.config(text = "New BTN", command=self.new_button)
self.new_button.grid(row=1,column=0)
self.hi_there.config(state=DISABLED)
def createWidgets(self):
self.QUIT = Button(self)
self.QUIT.config(text="QUIT",fg="red",command=self.quit)
self.QUIT.grid(row=0,column=1)
self.hi_there = Button(self)
self.hi_there["text"] = "Hello",
self.hi_there["command"] = self.say_hi
self.hi_there.grid(row=0,column=0)
def quit(self):
self.master.destroy()
def testit():
root = Tk()
app = Application(master=root)
app.mainloop()
if __name__ == '__main__':
testit()

Initially, self.new_button refers to a method. Then, you do this:
self.new_button = Button(self)
That effecting removes the method and replaces it with the button widget itself.
Also, you never assign a command to the new button, so clicking it doesn't cause anything to be called.

Where your program will technically work just fine with the 2 correction mentioned in Bryan's answer I am not sure why you are taking all the extra effort configuring the widgets for each individual field. All your configs can be done when you create the widget.
That said you can also change a few things for a cleaner code and 1 change I think that really needs to be made is how you are removing the new_button from the grid. When you do grid_remove() this only takes the widget off the screen but does not get rid of the widget. Then next time you press the say_hi button you will end up creating a new button and the old button will still exist. Instead I think I would use destroy() on the button and then let say_hi recreate it.
See this revised version of your code. You will see what I mean about configuring everything when creating the widget and also you do not need to write your own function for quit you can simply do self.master.destroy in the quit button command.
import tkinter as tk
class Application(tk.Frame):
def __init__(self, master=None):
tk.Frame.__init__(self, master)
self.master = master
self.master.geometry('300x100+10+10')
self.create_widgets()
def new_btn(self):
print("enable_b")
self.hi_there.config(state="active")
self.new_button.destroy()
def say_hi(self):
print("hi there, everyone!")
self.new_button = tk.Button(self, text="New BTN", command=self.new_btn)
self.new_button.grid(row=1, column=0)
self.hi_there.config(state="disabled")
def create_widgets(self):
tk.Button(self, text="QUIT", fg="red", command=self.master.destroy).grid(row=0,column=1)
self.hi_there = tk.Button(self, text="Hello", command=self.say_hi)
self.hi_there.grid(row=0, column=0)
if __name__ == '__main__':
root = tk.Tk()
app = Application(master=root).pack()
root.mainloop()

How to use TkInter fill or expand functions with self?

I have a very simple program with TkInter in Python.
How to I use the "fill" or "expand" options with the following code?
from Tkinter import *
class Application(Frame):
def sayhello(self):
print "Hello!"
def createWidgets(self):
self.var = Button(self, text="Hello", command = self.sayhello)
self.var.pack(side=LEFT)
self.QUIT = Button(self, text="QUIT", fg="red", command = self.quit)
self.QUIT.pack(side=LEFT)
def __init__(self, master=None):
Frame.__init__(self, master)
self.pack()
self.createWidgets()
root = Tk()
app = Application(master=root)
app.mainloop()
root.destroy()
Note: I have to use the self.var.pack() format so it can do a "command" when it's pressed...unless anyone has a better way?

To make an object fill it's container in the y axis, you would use the parameter fill="y" (or fill=Y if you import Y from Tkinter).
Note that this only controls how the widget fills its container. In your code, this makes the button fill the inner frame, but because your inner frame doesn't fill the main window in the y axis, you might not get the visual effect you expect.
Also, specifically in the case of buttons on the Macintosh, the button won't grow to fill the space. On OSX, buttons are native widgets which can't grow in height.