tkinter Button command argument with lambda

Question

I'm pretty new to programming in general, and have been learning the basics of Python. I wanted to learn some GUI stuff so I looked into some tutorials on using tkinter. I'm following along with this tutorial to create a simple calculator right now: https://www.geeksforgeeks.org/python-simple-gui-calculator-using-tkinter/

Towards the bottom of the code, they create all the calculator buttons individually. I thought it would be cleaner and easier to create a function and use a for-loop to run through and create each button. It works fine except when I press the buttons they only update the entry field to the "/" symbol, the last index of my buttons tuple. Any ideas why this could be happening? Full code below:

import tkinter as tk


def create_buttons():
    """
    adds calculator buttons in a for loop, resetting column and row when max is hit
    """

    buttons = ("1","2","3","+","4","5","6","-","7","8","9","*", "Clear", "0", "=", "/")
    column = 0
    row = 2

    for i in buttons:
        new_button = tk.Button(calc, text=i, fg="black", bg="red", height=2, width=10, command=lambda: press(i))
        new_button.grid(column=column, row=row)
    
        if column == 3:
            column = 0
            row += 1
        else:
            column += 1


def press(button):
    equation.set(button)


if __name__ == "__main__":
    calc = tk.Tk()
    calc.title("Calculator")
    calc.geometry("400x300")
    calc.configure(background="light green")

    equation = tk.StringVar()

    expression_field = tk.Entry(calc, textvariable=equation)
    expression_field.grid(columnspan=4, ipadx=130)

    create_buttons()

    calc.mainloop()

(I know the calculator doesn't actually do anything yet, I just wanted to test that this was working and got stuck here.)

tkinter Button command argument with lambda

0 Answers0