How to set the text/value/content of an `Entry` widget using a button in tkinter

You can choose between the following two methods to set the text of an Entry widget. For the examples, assume imported library import tkinter as tk and root window root = tk.Tk().

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• Method A: Use delete and insert

  Widget Entry provides methods delete and insert which can be used to set its text to a new value. First, you'll have to remove any former, old text from Entry with delete which needs the positions where to start and end the deletion. Since we want to remove the full old text, we start at 0 and end at wherever the end currently is. We can access that value via END. Afterwards the Entry is empty and we can insert new_text at position 0.

  entry = tk.Entry(root)
  new_text = "Example text"
  entry.delete(0, tk.END)
  entry.insert(0, new_text)
  

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• Method B: Use StringVar

  You have to create a new StringVar object called entry_text in the example. Also, your Entry widget has to be created with keyword argument textvariable. Afterwards, every time you change entry_text with set, the text will automatically show up in the Entry widget.

  entry_text = tk.StringVar()
  entry = tk.Entry(root, textvariable=entry_text)
  new_text = "Example text"
  entry_text.set(new_text)
  

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• Complete working example which contains both methods to set the text via Button:

  This window

  

  is generated by the following complete working example:

  import tkinter as tk
  
  def button_1_click():
      # define new text (you can modify this to your needs!)
      new_text = "Button 1 clicked!"
      # delete content from position 0 to end
      entry.delete(0, tk.END)
      # insert new_text at position 0
      entry.insert(0, new_text)
  
  def button_2_click():
      # define new text (you can modify this to your needs!)
      new_text = "Button 2 clicked!"
      # set connected text variable to new_text
      entry_text.set(new_text)
  
  root = tk.Tk()
  
  entry_text = tk.StringVar()
  entry = tk.Entry(root, textvariable=entry_text)
  
  button_1 = tk.Button(root, text="Button 1", command=button_1_click)
  button_2 = tk.Button(root, text="Button 2", command=button_2_click)
  
  entry.pack(side=tk.TOP)
  button_1.pack(side=tk.LEFT)
  button_2.pack(side=tk.LEFT)
  
  root.mainloop()
  

You might want to use insert method. You can find the documentation for the Tkinter Entry Widget here.

This script inserts a text into Entry. The inserted text can be changed in command parameter of the Button.

from tkinter import *

def set_text(text):
    e.delete(0,END)
    e.insert(0,text)
    return

win = Tk()

e = Entry(win,width=10)
e.pack()

b1 = Button(win,text="animal",command=lambda:set_text("animal"))
b1.pack()

b2 = Button(win,text="plant",command=lambda:set_text("plant"))
b2.pack()

win.mainloop()

If you use a "text variable" tk.StringVar(), you can just set() that.

No need to use the Entry delete and insert. Moreover, those functions don't work when the Entry is disabled or readonly! The text variable method, however, does work under those conditions as well.

import Tkinter as tk

...

entry_text = tk.StringVar()
entry = tk.Entry( master, textvariable=entry_text )
entry_text.set( "Hello World" )