Talk:Tkinter

1. Python program to create a simple GUI
2. calculator using Tkinter

1. import everything from tkinter module

from tkinter import *

1. globally declare the expression variable

expression = ""

1. Function to update expression
2. in the text entry box

def press(num):

   # point out the global expression variable
   global expression

   # concatenation of string
   expression = expression + str(num)

   # update the expression by using set method
   equation.set(expression)

1. Function to evaluate the final expression

def equalpress():

   # Try and except statement is used
   # for handling the errors like zero
   # division error etc.

   # Put that code inside the try block
   # which may generate the error
   try:

       global expression

       # eval function evaluate the expression
       # and str function convert the result
       # into string
       total = str(eval(expression))

       equation.set(total)

       # initialize the expression variable
       # by empty string
       expression = ""

   # if error is generate then handle
   # by the except block
   except:

       equation.set(" error ")
       expression = ""

1. Function to clear the contents
2. of text entry box

def clear():

   global expression
   expression = ""
   equation.set("")

1. Driver code

if __name__ == "__main__":

   # create a GUI window
   gui = Tk()

   # set the background colour of GUI window
   gui.configure(background="light green")

   # set the title of GUI window
   gui.title("Simple Calculator")

   # set the configuration of GUI window
   gui.geometry("270x150")

   # StringVar() is the variable class
   # we create an instance of this class
   equation = StringVar()

   # create the text entry box for
   # showing the expression .
   expression_field = Entry(gui, textvariable=equation)

   # grid method is used for placing
   # the widgets at respective positions
   # in table like structure .
   expression_field.grid(columnspan=4, ipadx=70)

   # create a Buttons and place at a particular
   # location inside the root window .
   # when user press the button, the command or
   # function affiliated to that button is executed .
   button1 = Button(gui, text=' 1 ', fg='black', bg='red',
                   command=lambda: press(1), height=1, width=7)
   button1.grid(row=2, column=0)

   button2 = Button(gui, text=' 2 ', fg='black', bg='red',
                   command=lambda: press(2), height=1, width=7)
   button2.grid(row=2, column=1)

   button3 = Button(gui, text=' 3 ', fg='black', bg='red',
                   command=lambda: press(3), height=1, width=7)
   button3.grid(row=2, column=2)

   button4 = Button(gui, text=' 4 ', fg='black', bg='red',
                   command=lambda: press(4), height=1, width=7)
   button4.grid(row=3, column=0)

   button5 = Button(gui, text=' 5 ', fg='black', bg='red',
                   command=lambda: press(5), height=1, width=7)
   button5.grid(row=3, column=1)

   button6 = Button(gui, text=' 6 ', fg='black', bg='red',
                   command=lambda: press(6), height=1, width=7)
   button6.grid(row=3, column=2)

   button7 = Button(gui, text=' 7 ', fg='black', bg='red',
                   command=lambda: press(7), height=1, width=7)
   button7.grid(row=4, column=0)

   button8 = Button(gui, text=' 8 ', fg='black', bg='red',
                   command=lambda: press(8), height=1, width=7)
   button8.grid(row=4, column=1)

   button9 = Button(gui, text=' 9 ', fg='black', bg='red',
                   command=lambda: press(9), height=1, width=7)
   button9.grid(row=4, column=2)

   button0 = Button(gui, text=' 0 ', fg='black', bg='red',
                   command=lambda: press(0), height=1, width=7)
   button0.grid(row=5, column=0)

   plus = Button(gui, text=' + ', fg='black', bg='red',
               command=lambda: press("+"), height=1, width=7)
   plus.grid(row=2, column=3)

   minus = Button(gui, text=' - ', fg='black', bg='red',
               command=lambda: press("-"), height=1, width=7)
   minus.grid(row=3, column=3)

   multiply = Button(gui, text=' * ', fg='black', bg='red',
                   command=lambda: press("*"), height=1, width=7)
   multiply.grid(row=4, column=3)

   divide = Button(gui, text=' / ', fg='black', bg='red',
                   command=lambda: press("/"), height=1, width=7)
   divide.grid(row=5, column=3)

   equal = Button(gui, text=' = ', fg='black', bg='red',
               command=equalpress, height=1, width=7)
   equal.grid(row=5, column=2)

   clear = Button(gui, text='Clear', fg='black', bg='red',
               command=clear, height=1, width=7)
   clear.grid(row=5, column='1')

   Decimal= Button(gui, text='.', fg='black', bg='red',
                   command=lambda: press('.'), height=1, width=7)
   Decimal.grid(row=6, column=0)
   # start the GUI
   gui.mainloop()

Simpler Example

I suggest that the example under A minimal application should be made more simpler and it should be changed to a Hello, world! example. Thoughts? --I8086 (talk) 12:49, 13 March 2015 (UTC)

I agree and disagree. This should be the second example and a simple Hello, world! example with out the need for a class structure should be the first. I think there are many other issues and concepts that need to be introduced. To be of practical use we need a menubar structure, and canvas too. --ClemRutter (talk) 17:47, 16 August 2018 (UTC)

Is Tkinter still the de facto Python GUI?

In 2021, there are a lot of different libraries to write GUIs, among them GTK and Qt. Should the introductory sentence be edited? 2601:281:C500:37:5D60:623F:7A0F:F317 (talk) 00:27, 17 March 2021 (UTC)

Nope. Tkinter is still one of the most relevant GUIs. Didlidoo (talk) 06:14, 4 September 2024 (UTC)

And that is because Tcl/Tk is a great language for cross-platform GUI development, BUT putting Tcl/Tk on your resume is considered suicidal... So wrapping an entire Tcl language interpreter in python and translating a bunch of nonsense code into Tcl/Tk at runtime is the pathetic result. Now that Python has an event loop there is no excuse for not dropping the charade. — Preceding unsigned comment added by 2600:1700:6AE5:2510:0:0:0:40 (talk) 18:24, 5 December 2024 (UTC)

root=none?

The first example creates a root element before using it. The second example just uses root=none during initialization, and does no patching or registration when changing it to a real object. This is worth an explanation in the line-by-line notes below. JimJJewett (talk) 23:19, 27 February 2026 (UTC)