Pygame PlayerRect global variable not working

Question

I want to check if two rects collide in pygame and the global keyword isn't working

Here is the code for the player and for the enemy:

#player   
def player():
    global xPlayer, yPlayer
    global playerRect
    playerRect = pygame.Rect(xPlayer,yPlayer, 15, 15)
    pygame.draw.rect(screen,(0,0,253),playerRect)
    keys = pygame.key.get_pressed()

    if keys[pygame.K_RIGHT] and xPlayer < 971:
        xPlayer += velPlayer
    if keys[pygame.K_LEFT] and xPlayer > 0:
        xPlayer -= velPlayer
    if keys[pygame.K_UP] and yPlayer > 0:
        yPlayer -= velPlayer
    if keys[pygame.K_DOWN] and yPlayer < 970:
        yPlayer += velPlayer
        
def enemy():
    global xEnemy,yEnemy, xPlayer, yPlayer, playerRect
    enemyRect = pygame.Rect(xEnemy,yEnemy,15,15)
    pygame.draw.rect(screen,(255,0,0),enemyRect)