Цифровая клавиатура

#-*-coding: utf-8-*-
from tkinter import Button,Entry,END,Tk
import math
 
class calc:
    def getandreplace(self):
        """replace x with * and ? with /"""
        
        self.expression = self.e.get()
        self.newtext=self.expression.replace(self.newdiv,'/')
        self.newtext=self.newtext.replace('x','*')
 
    def equals(self):
        """when the equal button is pressed"""
 
        self.getandreplace()
        try: 
            self.value= eval(self.newtext) #evaluate the expression using the eval function
        except SyntaxError or NameErrror:
            self.e.delete(0,END)
            self.e.insert(0,'Invalid Input!')
        else:
            self.e.delete(0,END)
            self.e.insert(0,self.value)
    
    def squareroot(self):
        """squareroot method"""
        
        self.getandreplace()
        try: 
            self.value= eval(self.newtext) #evaluate the expression using the eval function
        except SyntaxError or NameErrror:
            self.e.delete(0,END)
            self.e.insert(0,'Invalid Input!')
        else:
            self.sqrtval=math.sqrt(self.value)
            self.e.delete(0,END)
            self.e.insert(0,self.sqrtval)
 
    def square(self):
        """square method"""
        
        self.getandreplace()
        try: 
            self.value= eval(self.newtext) #evaluate the expression using the eval function
        except SyntaxError or NameErrror:
            self.e.delete(0,END)
            self.e.insert(0,'Invalid Input!')
        else:
            self.sqval=math.pow(self.value,2)
            self.e.delete(0,END)
            self.e.insert(0,self.sqval)
    
    def clearall(self): 
        """when clear button is pressed,clears the text input area"""
        self.e.delete(0,END)
    
    def clear1(self):
        self.txt=self.e.get()[:-1]
        self.e.delete(0,END)
        self.e.insert(0,self.txt)
 
    def action(self,argi): 
        """pressed button's value is inserted into the end of the text area"""
        self.e.insert(END,argi)
    
    def __init__(self,master):
        """Constructor method"""
        master.title('Calulator') 
        master.geometry()
        self.e = Entry(master)
        self.e.grid(row=0,column=0,columnspan=6,pady=3)
        self.e.focus_set() #Sets focus on the input text area
                
        self.div='?'
        
        #Generating Buttons
        Button(master,text="=",width=10,command=lambda:self.equals()).grid(row=4, column=4,columnspan=2)
        Button(master,text='AC',width=3,command=lambda:self.clearall()).grid(row=1, column=4)
        Button(master,text='C',width=3,command=lambda:self.clear1()).grid(row=1, column=5)
        Button(master,text="+",width=3,command=lambda:self.action('+')).grid(row=4, column=3)
        Button(master,text="x",width=3,command=lambda:self.action('x')).grid(row=2, column=3)
        Button(master,text="-",width=3,command=lambda:self.action('-')).grid(row=3, column=3)
        Button(master,text="?",width=3,command=lambda:self.action(self.div)).grid(row=1, column=3) 
        Button(master,text="%",width=3,command=lambda:self.action('%')).grid(row=4, column=2)
        Button(master,text="7",width=3,command=lambda:self.action('7')).grid(row=1, column=0)
        Button(master,text="8",width=3,command=lambda:self.action(8)).grid(row=1, column=1)
        Button(master,text="9",width=3,command=lambda:self.action(9)).grid(row=1, column=2)
        Button(master,text="4",width=3,command=lambda:self.action(4)).grid(row=2, column=0)
        Button(master,text="5",width=3,command=lambda:self.action(5)).grid(row=2, column=1)
        Button(master,text="6",width=3,command=lambda:self.action(6)).grid(row=2, column=2)
        Button(master,text="1",width=3,command=lambda:self.action(1)).grid(row=3, column=0)
        Button(master,text="2",width=3,command=lambda:self.action(2)).grid(row=3, column=1)
        Button(master,text="3",width=3,command=lambda:self.action(3)).grid(row=3, column=2)
        Button(master,text="0",width=3,command=lambda:self.action(0)).grid(row=4, column=0)
        Button(master,text=".",width=3,command=lambda:self.action('.')).grid(row=4, column=1)
        Button(master,text="(",width=3,command=lambda:self.action('(')).grid(row=2, column=4)
        Button(master,text=")",width=3,command=lambda:self.action(')')).grid(row=2, column=5)
        Button(master,text="v",width=3,command=lambda:self.squareroot()).grid(row=3, column=4)
        Button(master,text="x?",width=3,command=lambda:self.square()).grid(row=3, column=5)
        
    
if __name__ == "__main__":
    #Main
    root = Tk()
    obj=calc(root) #object instantiated
    root.mainloop()