from tkinter import *
from tkinter.ttk import *


class HelloGui:
    def __init__(self, parent):
        """docstring showing innit function"""
        ops = ['+', '-', '*']
        self.name_entry = Entry(parent)
        self.name_entry.grid(row=0, column=0)
        self.name_entry2 = Entry(parent)
        self.name_entry2.grid(row=0, column=2)
        self.combo = Combobox(parent, values=ops)
        self.combo.grid(row=0, column=1)
        self.combo.bind('<<ComboboxSelected>>', self.calculator)
        self.combo.current(0)



        self.button = Button(parent, text='Calculate', command=self.calculator)
        self.button.grid(row=1, column=1)
        self.message_label = Label(parent, text='')
        self.message_label.grid(row=0, column=4)
        self.return_value = Label(parent, text='=')
        self.return_value.grid(row=0, column=3)

    def calculator(self):
        """shows message"""
        num = self.name_entry.get()
        num1 = self.name_entry2.get()
        operator = self.combo.get()
        maths = int(num) + operator + int(num1)
        self.message_label['text'] = maths



def main():
    window = Tk()
    gui = HelloGui(window)
    window.mainloop()

main()