How can i make the ball bounce in the right directions

Im making an air hokey game using pygame , but i have no idea how to make the ball bounce in the right direction when the player hits it.

i tried making the ball move in the x direction if the player hits it and if the player is under the ball or aboce it i made it move in the y and x direction but that didnt work

import pygame
import math
pygame.init()
screen = pygame.display.set_mode((800, 400))
background = pygame.image.load("ER.png")



player1 = pygame.image.load("eee.png")
px = 20
py = 148
change = 0
cy = 0
player2 = pygame.image.load("a.png")
px2 = 700
py2 = 148
cx2 = 0
cy2 = 0

ball = pygame.image.load("qw.png")
bx = 351
by = 148
chx = 0
chy = 0

def balls(x,y):
    screen.blit(ball,(x,y))
def p1(x, y):
    screen.blit(player1,(x , y))
def p2(x, y):
    screen.blit(player2,(x , y))  
def  colid(ex,ey, bx, by):
    d = math.sqrt((math.pow(ex - bx, 2)) + (math.pow(by - ey,2)))
    if d < 40:
        return True
    else:
        return False    


run = True
while run:
    screen.blit(background,(0,0))
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_d:
                change += 1
            if event.key == pygame.K_a:
                change += -1 
            if event.key == pygame.K_s:
                cy += 1
            if event.key == pygame.K_w:
                cy += -1 
            if event.key == pygame.K_LEFT:
                cx2 -= 1
                print(px2)
                print(py2)
            if event.key == pygame.K_RIGHT:
                cx2 += 1 
                print(px2)
                print(py2) 
            if event.key == pygame.K_DOWN:
                cy2 += 1
                print(px2)
                print(py2)
            if event.key == pygame.K_UP:
                cy2 += -1
                print(px2)
                print(py2)    
      
        if event.type == pygame.KEYUP:
            if event.key == pygame.K_d:
                change -= 1    
            if event.key == pygame.K_a:
                change += 1 
            if event.key == pygame.K_s:
                    cy -= 1
            if event.key == pygame.K_w:
                    cy += 1 
            if event.key == pygame.K_LEFT:
                cx2 += 1
            if event.key == pygame.K_RIGHT:
                cx2 -= 1  
            if event.key == pygame.K_DOWN:
                cy2 -= 1
            if event.key == pygame.K_UP:
                cy2 += 1 
    colide =  colid(bx, by, px, py)           



    if colide:
        print("colided")
                          
    
    bx += ch
    py2 += cy2
    px2 += cx2
    py += cy  
    px += change
    balls(bx,by)
    p1(px,py)
    p2(px2, py2)
  
    if px <=  -8:
        px = -8
    if px >=  326:
        px = 326    
    if py <=  -8:
        py = -8
    if py >= 312:
        py = 312  

    if px2 >=  712:
        px2 = 712 

    if py2 <=  -8:
        py2 = -8
    if py2 >= 312:
        py2 = 312   
    if px2 <=  378:
        px2 = 378        
    
    pygame.display.update()