Python Calculator Using Tkinter Source Code

How To Create A Calculator In Python and Tkinter

In This Python Tutorial we will See How To Make A Simple Windows Form Calculator Application To Do The Basic Operations (+, -, /, *) And Reset To Make Another Calc Using tkinter In Visual Code Editor .

Project Source Code:

import tkinter as tk 
from tkinter import *
from tkinter import ttk 
from tkinter.ttk import *

root = Tk()

buttons = []

btns_vals = {'0-0':'1','0-1':'2','0-2':'3','0-3':'4',
             '1-0':'5','1-1':'6','1-2':'7','1-3':'8',
             '2-0':'9','2-1':'0','2-2':'.','2-3':'=',
             '3-0':'+','3-1':'-','3-2':'/','3-3':'*',}


textbox = tk.Entry(root, width="30", font=("Arial",20))
textbox.grid(row="0", column="0", columnspan="4")


def displayVal(row_index, column_index):

    # get the textbox value
    textbox_val = textbox.get()
    # clear textbox
    textbox.delete(0,END)
    # get the clicked button value
    btn_val = buttons[row_index][column_index]['text']
    # new val 
    val = textbox_val + btn_val
    # display the new val in textbox
    textbox.insert(0,val)


# create a function to calculate
def calc(opr):
    if opr != '=':
        global calc_opr, number_1
        calc_opr = opr
        number_1 = float(textbox.get())
        textbox.delete(0,END)

    elif opr == '=':
        number_2 = float(textbox.get())
        if calc_opr == '+':
            val = number_1 + number_2
        elif calc_opr == '-':
            val = number_1 - number_2
        elif calc_opr == '/':
            val = number_1 / number_2
        elif calc_opr == '*':
            val = number_1 * number_2

        textbox.delete(0,END)
        textbox.insert(0,val)

    


# create a function to clear textbox
def clear():
    textbox.delete(0,END)


# display buttons
for i in range(4):
    btn_row = []
    for j in range(4):
        key = "{i}-{j}".format(i=i,j=j)
        button = tk.Button(root, padx=15, pady=15, text = btns_vals[key], 
                           font=("Arial",20))

        if btns_vals[key] not in ('=','+','-','*','/'):
            button['bg'] = 'Black'
            button['fg'] = 'White' 
            button['command'] = lambda theRow = i, 
                                       theCol = j : displayVal(theRow, theCol)

        else:
            button['bg'] = 'Orange'
            button['fg'] = 'White'
            button['command'] = lambda operation = btns_vals[key] : calc(operation)    


        button.grid(row=i+1, column=j, sticky="nsew")

        btn_row.append(button)

    buttons.append(btn_row)


button = tk.Button(root, padx=15, pady=15,bg="grey", text = 'c', font=("Arial",20))
button['command'] = clear
button.grid(row=5,column=0,columnspan=4, sticky="nsew")

root.mainloop()