Program stopped working when using try and except within tkinter

Question

I am trying to use the try and except in tkinter. The try is working fine but the except makes my program stop running and it closes the window.

try:
   num1 = int(self.valx1.get())
   num2 = int(self.valy1.get())
   num3 = int(self.valx2.get())
   num4 = int(self.valy2.get())
   DDALine(num1,num2,num3,num4).main()
   
except ValueError:
   self.lblerror.config(text="Please enter integer number only.")
   print("Please enter integer number only.")'''

Please help me, I have been on this for hours and have been searching all over Stack Overflow.

Thanks in advance!