[Tkinter] tkinter.TclError: expected integer but got " "

[TWB]

Hello all,
I am trying to build a function that i can use to check a imput field that requires a integer to make sure a character hasn't been entered.
Anything I try gives me a error "tkinter.TclError: expected integer but got " "
It seems to catch the error before i can run any error checking
I have attached a snippet of the code below that is executable
Any help is always appreciated

# Introduction to Python Programming
from tkinter import *
import shelve
import tkinter as tk
from tkinter import ttk

class MyFrame (Frame):
    def __init__(self):
        Frame.__init__(self)
        self.master.geometry("600x600")
        self.master.title("Student Scores")
        self.grid()

        #Display menue here here
        self.student_score = IntVar()
        self.student_score.set("")

        #label to prompt for input of score
        self.prompt = Label(self, text = "Enter students score: ")
        self.prompt.grid(row = 3, column = 0, sticky="W")
      
        #enable text field for score input
        self.input = Entry(self,textvariable=self.student_score)
        self.input.grid(row = 3, column = 2)
           
        #submit button
        self.button_submit = Button(self, text = "Submit", command = self.enter_student_scores)
        self.button_submit.grid(row = 10, column = 0, pady=20)

    #function to see entered student names and scores
    def enter_student_scores(self):
        student_score = self.student_score.get()
        #print output
        print(" Student Score is ",student_score)
        
    # function for error checking
    def error_checking(self):
        score = self.student_score.get()
        try:
            x = int(score)
            print("int is entered")
        except ValueError:
                print("Not a proper integer! Try it again")
     
asn_frame = MyFrame()
asn_frame.mainloop()