from tkinter import *

root = Tk()
root.title("Simple Calculator")

e = Entry(root, width= 35, borderwidth=5)
e.grid(row=0, column=0, columnspan=3, padx=10, pady=10)


def button_click(number):
	#e.delete(0, END)
	current= e.get()
	e.delete(0, END)
	e.insert(0, str(current) + str(number))

def button_clear():
	e.delete(0, END)

def button_add():
	first_number = e.get()
	global f_num
	global math
	math = "addition"
	f_num = int(first_number)
	e.delete(0, END)

def button_equal():
	second_number = e.get()
	e.delete(0,END)

	if math == "addition":
		e.insert(0, f_num + int(second_number))

	if math == "substraction":
		e.insert(0, f_num - int(second_number))

	if math == "multiplication":
		e.insert(0, f_num * int(second_number))

	if math == "devision":
		e.insert(0, f_num / int(second_number))

def button_substract():
	first_number = e.get()
	global f_num
	global math
	math = "substraction"
	f_num = int(first_number)
	e.delete(0, END)

def button_multiply():
	first_number = e.get()
	global f_num
	global math
	math = "multiplication"
	f_num = int(first_number)
	e.delete(0, END)

def button_devide():
	first_number = e.get()
	global f_num
	global math
	math = "devision"
	f_num = int(first_number)
	e.delete(0, END)



button_1= Button(root, text="1", padx=40, pady=20, command=lambda: button_click(1))
button_2= Button(root, text="2", padx=40, pady=20, command=lambda: button_click(2))
button_3= Button(root, text="3", padx=40, pady=20, command=lambda: button_click(3))
button_4= Button(root, text="4", padx=40, pady=20, command=lambda: button_click(4))
button_5= Button(root, text="5", padx=40, pady=20, command=lambda: button_click(5))
button_6= Button(root, text="6", padx=40, pady=20, command=lambda: button_click(6))
button_7= Button(root, text="7", padx=40, pady=20, command=lambda: button_click(7))
button_8= Button(root, text="8", padx=40, pady=20, command=lambda: button_click(8))
button_9= Button(root, text="9", padx=40, pady=20, command=lambda: button_click(9))
button_0= Button(root, text="0", padx=40, pady=20, command=lambda: button_click(0))
button_add= Button(root, text="+", padx=39, pady=20, command=button_add)
button_equal= Button(root, text="=", padx=91, pady=20, command=button_equal)
button_clear= Button(root, text="Clear", padx=79, pady=20, command=button_clear)

button_substract= Button(root, text="-", padx=40, pady=20, command=button_substract)
button_multiply= Button(root, text="*", padx=40, pady=20, command=button_multiply)
button_devide= Button(root, text="/", padx=40, pady=20, command=button_devide)


button_1.grid(row=3, column=0)
button_2.grid(row=3, column=1)
button_3.grid(row=3, column=2)

button_4.grid(row=2, column=0)
button_5.grid(row=2, column=1)
button_6.grid(row=2, column=2)

button_7.grid(row=1, column=0)
button_8.grid(row=1, column=1)
button_9.grid(row=1, column=2)

button_0.grid(row=4, column=0)
button_clear.grid(row=4, column=1, columnspan=2)
button_add.grid(row=5, column=0)
button_equal.grid(row=5, column=1, columnspan=2)

button_substract.grid(row=6, column=0)
button_multiply.grid(row=6, column=1)
button_devide.grid(row=6, column=2)




root.mainloop()
