How to to properly use a checkbox to delete itself in tkinter?

Question

I am a beginner in python, I used tkinter to build a to-do list program. But the problem is I don't understand how it works.

from tkinter import *

root = Tk()

def insert_Task(name):
    name = Checkbutton(root, text=name, command= lambda: del_task(name))
    name.pack()
    
def del_task(name):
    name.destroy()
    
insert_Entry = Entry(root)
insert_Button = Button(root, text="Ok", command=lambda: insert_Task(insert_Entry.get()))

insert_Entry.pack()
insert_Button.pack()

root.mainloop()

The only way this should work is when name is passed into text, it is insert_Entry.get() and when the function is called it is the Checkbutton object.

Can someone explain to me if this is the case?

It sounds like you're saying your code works, you just don't know how — correct? — martineau, Aug 27 '21 at 09:38
I don't 100% get your question but if your question is: why is `del_task` called with a `Checkbutton` object instead of a `str` object, look at [this](https://stackoverflow.com/a/10865170/11106801). — TheLizzard, Aug 27 '21 at 10:57

score 0 · Answer 1 · answered Aug 27 '21 at 08:49

lambdas are used to create anonymous functions. The code:

command=lambda: insert_Task(insert_Entry.get())

Can also be written as:

def click_next(): #=== any name
    insert_Task(insert_Entry.get())

insert_Button=Button(....,command = click_next)

Why do we use lambda to pass arguments?
We need to pass the reference of the function, i.e without providing a (). Or else, the function is executed right away and the returned value is set as the command.

When you click on the button, insert_Entry.get() returns all the text which is entered in insert_Entry. This is passed as the argument in insert_Task where a Check button is created with that name.

Similarly:

name = Checkbutton(root, text=name, command= lambda: del_task(name))

in this, a reference of the Checkbutton is passed as an argument to del_task so that on clicking on it, the method in invoked and the selected check button is destroyed

So, basically when lambda are used, the argument inside del_task function is referring to the Checkbox itself and when lambda is not used it is referring to the value inside of insert_Entry. — bababooey2, Aug 27 '21 at 12:34

How to to properly use a checkbox to delete itself in tkinter?

1 Answers1