How do I check if two balls collide in tkinter?

Working on a small project involving tkinter and I need to figure out how to get balls bouncing off of each other.

Heres the code:

from tkinter import *

# dimensions of canvas
WIDTH=300
HEIGHT=400

# Create window and canvas
window = Tk()
canvas = Canvas(window, width=WIDTH, height=HEIGHT, bg='#ADF6BE')
canvas.pack()

# starting position of ball
x = 0
y = 10
# starting position of ball1
x1 = 100
y1 = 0

# distance moved each time step for ball 1
dx = 10
dy= 10
# distance moved each time step for ball 2
dx1 = 10
dy1 = 10

# diameter of ball
ballsize = 30


while True:
   x = x + dx
   y = y + dy
   x1 = x1 + dx1
   y1 = y1 + dy1

   # if ball get to edge then we need to
   # change direction of movement
   if x >= WIDTH-ballsize or x <= 0 or x == x1:
      dx = -dx
      print("x=", x)
      print('y=', y)
   if y >= HEIGHT-ballsize or y <= 0 or y == y1:
      dy = -dy
      print("x=", x)
      print('y=', y)

   if x1 >= WIDTH-ballsize or x1 <= 0 or x1 == x:
      dx1 = -dx1
      print("x1=", x1)
      print('y1=', y1)
   if y1 >= HEIGHT-ballsize or y1 <= 0 or y1 == y:
      dy1 = -dy1
      print("x1=", x1)
      print('y1=', y1)


   # Create balls
   ball=canvas.create_oval(x, y, x+ballsize, y+ballsize, fill="white", outline='white')
   ball1 = canvas.create_oval(x1, y1, x1 + ballsize, y1 + ballsize, fill="white", outline='white')
   # display ball
   canvas.update()
   canvas.after(50)
   #remove ball
   canvas.delete(ball)
   canvas.delete(ball1)

window.mainloop()

They move and bounce off of the canvas walls but not off of each other.

Heres an image to show what I mean, instead of hitting each other and bouncing off