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Tkinter binding a function with arguments to a widget


Tkinter widgets are the building blocks that come with some predefined operations. To handle a specific functionality of an application, we bind the keys to some widgets.

We can bind an event to widgets using the bind(‘key’, callback function) method. Key represents the event through which we target a particular event, whereas callable function activates the event. To create a callback function, we switch to a specific widget as the argument and then add the particular event.

Example

Let us understand this with an example where we have to bind the <Enter> key with a function that displays some text on the window. Whenever the button is clicked or <Enter> key is pressed, the callback function executes and the event happens.

#Import the Tkinter library
from tkinter import *
#Create an instance of Tkinter frame
win= Tk()
#Define the geometry
win.geometry("750x250")
#Define Event handlers with arguments
def event_show(event):
   button.config(bg="red", fg= "white")
   label.config(text="Hello World")
#Create a Label
label= Label(win, text="",font=('Helvetica 15 underline'))
label.pack()
#Create a frame
frame= Frame(win)
#Create Buttons in the frame
button= Button(frame, text="Click",command=lambda:event_show(button))
button.pack(pady=10)
frame.pack()
#Bind the function
win.bind('<Return>',lambda event:event_show(event))
win.mainloop()

Output

Running the above code will display a window that contains a button. The button event can bed triggered through two ways − Enter Key and Click Event.

Tkinter binding a function with arguments to a widget

Now, press Enter or click the button to display the output on the screen.