from tkinter import *

root = Tk()

root.title("Simple Calulator")

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

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

def get_number():
  first_number = e.get()
  global f_num
  f_num = int(first_number)
  e.delete(0,END)

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

def button_add():
  get_number()
  global oprtr
  oprtr = "add"

def button_subtract():
  get_number()
  global oprtr
  oprtr = "subtract"

def button_multiply():
  get_number()
  global oprtr
  oprtr = "multiply"

def button_divide():
  get_number()
  global oprtr
  oprtr = "divide"

def button_equal():
  second_number = e.get()
  e.delete(0,END)
  if oprtr == "add":
    result = f_num + int(second_number)
  elif oprtr == "subtract":
    result = f_num - int(second_number)
  elif oprtr == "multiply":
    result = f_num * int(second_number)
  elif oprtr == "divide":
    result = f_num / int(second_number)

  e.insert(0,result)
# Define Buttons

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_subtract = Button(root, text="-", padx=39, pady=20, command=button_subtract)
button_multiply = Button(root, text="x", padx=39, pady=20, command=button_multiply)
button_divide = Button(root, text="/", padx=39, pady=20, command=button_divide)

button_equal = Button(root, text="=", padx=99, pady=20, command =button_equal)
button_clear = Button(root, text="Clear", padx=87, pady=20, command=button_clear)


# Show Buttons on screen
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_equal.grid(row=5, column=1, columnspan=2)
button_add.grid(row=5, column=0)

button_subtract.grid(row=6, column=0)
button_multiply.grid(row=6, column=1)
button_divide.grid(row=6, column=2)


root.mainloop()