CODEWITHSUNDEEP
pythonwindowspython-3.xwindows-8tkinter
user3687970
user3687970

Reputation: 23

to create a button when pressed print the number on that button in the entry box in python 3.3

i want to make a button on which '2' is written .... now when anyone click it , it will show the number '2' in the entry box... the error is: before clicking , it is already showing '2' in the entry box

So please help me removing this error here is my program

from tkinter import * 

root = Tk()  
def add(x):  
    e1=Entry(root)  
    e1.insert(INSERT, x)  
    e1.pack()

a=Button(root, text='2', command=add(2))  
a.pack()

root.mainloop()

Upvotes: 1

Views: 675

Answers (2)

falsetru
falsetru

Reputation: 368954

Pass a function (used lambda in the following code) instead of return value of the function.

from tkinter import * 

root = Tk()  
e1 = Entry(root)  
e1.pack()

def add(x):  
    e1.insert(INSERT, x)  

a = Button(root, text='2', command=lambda: add(2))
a.pack()

root.mainloop()

In addition to that, extract Entry creation code out of the add function. Otherwise entry are create every time when the button is clicked.

Upvotes: 2

jonrsharpe
jonrsharpe

Reputation: 121966

When you do:

a=Button(root, text='2', command=add(2))

it is the same as:

add(2)
a=Button(root, text='2', command=None)

i.e. you are calling add and assigning its return value to command. Instead, you can use functools.partial to create a function that will call add with the argument 2:

from functools import partial

a=Button(root, text='2', command=partial(add, 2))

Upvotes: 1

Related Questions