this constructor takes no arguments

问题

I'd like to make a simple calculator in Tkinter. I've got few lines of code and want to check if it works. But then I recevie such error: "Calc(T.Tk()).run() this constructor takes no arguments". Here is my code:

# -*- coding: utf-8 -*-

import Tkinter as T
from Tkinter import W, E

class Calc():
    def _init_(self,main):
        self.main = main
        self.main.title('Calculator')
        self.main.config(bg = 'black')
        self.e = T.Entry(self.main, justify = 'center')
        self.e.grid(row = 0, columnspan = 5, sticky = W + E)

        self.e.pack()


    def run(self):
        self.main.mainloop()



Calc(T.Tk()).run()  

回答1:

def _init_(self, main):

should be:

def __init__(self, main):

You need double underscores.

回答2:

Name your method __init__ with two underscores on each side.

来源：https://stackoverflow.com/questions/19929872/this-constructor-takes-no-arguments