Calculator Project in Python Programming 💻✅

Source Code:

from tkinter import *

win = Tk()
win.geometry("312x324")
win.title("Calculator")

def btn_click(item):
global expression
expression=expression + str(item)
input_text.set(expression)

def bt_clear():
global expression
expression = ""
input_text.set("")

def bt_equal():
global expression
result = str(eval(expression))
'eval':This function is used to evaluates the string expression directly
input_text.set(result)
expression = ""



expression=""

StringVar(): It is used to get the instance of input field

input_text =StringVar()

input_frame=Frame(win,width=312,height=50,bd=0,highlightbackground='black',
highlightcolor='black',highlightthickness=2)

input_frame.pack(side=TOP)

input_field=Entry(input_frame,font=('arial',18,'bold'),textvariable=input_text,width=50
,bg="#eee",bd=0,justify=RIGHT)

input_field.grid(row=0,column=0)

input_field.pack(ipady=10)

btns_frame=Frame(win,width=312,height=272.5,bg='grey')

btns_frame.pack()

First row of calculator

clear = Button(btns_frame, text = "C", fg = "black", width = 32, height = 3, bd = 0, bg = "#eee",
cursor = "hand2", command = lambda: bt_clear()
).grid(row = 0, column = 0, columnspan = 3, padx = 1, pady = 1)
divide = Button(btns_frame, text = "/", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee",
cursor = "hand2", command = lambda: btn_click("/")
).grid(row = 0, column = 3, padx = 1, pady = 1)

Row 2

seven = Button(btns_frame, text = "7", fg = "black", width = 10, height = 3,bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(7)
).grid(row = 1, column = 0, padx = 1, pady = 1)

eight = Button(btns_frame, text = "8", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(8)
).grid(row = 1, column = 1, padx = 1, pady = 1)

nine = Button(btns_frame, text = "9", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(9)
).grid(row = 1, column = 2, padx = 1, pady = 1)

multiply = Button(btns_frame, text = "*", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee",
cursor = "hand2", command = lambda: btn_click("*")
).grid(row = 1, column = 3, padx = 1, pady = 1)

Row 3

four = Button(btns_frame, text = "4", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(4)
).grid(row = 2, column = 0, padx = 1, pady = 1)

five = Button(btns_frame, text = "5", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(5)
).grid(row = 2, column = 1, padx = 1, pady = 1)

six = Button(btns_frame, text = "6", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(6)
).grid(row = 2, column = 2, padx = 1, pady = 1)

minus = Button(btns_frame, text = "-", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee",
cursor = "hand2", command = lambda: btn_click("-")
).grid(row = 2, column = 3, padx = 1, pady = 1)


Row 4

one = Button(btns_frame, text = "1", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(1)
).grid(row = 3, column = 0, padx = 1, pady = 1)

two = Button(btns_frame, text = "2", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(2)
).grid(row = 3, column = 1, padx = 1, pady = 1)

three = Button(btns_frame, text = "3", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(3)
).grid(row = 3, column = 2, padx = 1, pady = 1)

plus = Button(btns_frame, text = "+", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee",
cursor = "hand2", command = lambda: btn_click("+")
).grid(row = 3, column = 3, padx = 1, pady = 1)


Last part

zero = Button(btns_frame, text = "0", fg = "black", width = 21, height = 3, bd = 0, bg = "#fff",
cursor = "hand2", command = lambda: btn_click(0)
).grid(row = 4, column = 0, columnspan = 2, padx = 1, pady = 1)

point = Button(btns_frame, text = ".", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee",
cursor = "hand2", command = lambda: btn_click(".")
).grid(row = 4, column = 2, padx = 1, pady = 1)

equals = Button(btns_frame, text = "=", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee",
cursor = "hand2", command = lambda: bt_equal()
).grid(row = 4, column = 3, padx = 1, pady = 1)


win.mainloop()