how to set how fast a gun shoots/fire-rate of a gun in pygame

Question

I think similar questions have been asked but they didn't help! The way it works is that the player left clicks to shoot but I don't them to be able to just spam left click to shoot I have tried things like tracking how many bullets are currently on the screen but it doesn't work.

basically, the goal is to set a fire rate. When I hold a key, the weapon should fire, but not crazy fast.

here is the code if it will help...

import pygame
from sys import exit
from random import randint
import math
from pygame.math import Vector2
from pygame.constants import K_LSHIFT, K_SPACE, MOUSEBUTTONDOWN, MOUSEBUTTONUP, K_e
pygame.init()
import time
pygame.mouse.set_visible(True)




class Player(pygame.sprite.Sprite):
    def __init__(self, x , y):
        super().__init__()
        self.x = x
        self.y = y
        self.image = pygame.image.load('graphics/Robot 1/robot1_gun.png').convert_alpha()
        self.rect = self.image.get_rect()
        self.orig_image = pygame.image.load('graphics/Robot 1/robot1_gun.png').convert_alpha()
        self.rotate_vel = 1
        self.cross_image = pygame.image.load('graphics/crosshair049.png')
        

    def draw(self, surface):
        """ Draw on surface """
        # blit yourself at your current position
        surface.blit(self.image, self.rect)
        dir_vec = pygame.math.Vector2()
        dir_vec.from_polar((180, -self.rotate_vel))
        cross_pos = dir_vec + self.rect.center
        cross_x, cross_y = round(cross_pos.x), round(cross_pos.y)
        surface.blit(self.cross_image,  self.cross_image.get_rect(center = (cross_x, cross_y)))
        

    def movement(self):
        key = pygame.key.get_pressed()
        self.rect = self.image.get_rect(center = (self.x, self.y))
        dist = 3 # distance moved in 1 frame, try changing it to 5
        if key[pygame.K_DOWN] or key[pygame.K_s]: # down key
            self.y += dist # move down
        elif key[pygame.K_UP] or key[pygame.K_w]: # up key
            self.y -= dist # move up
        if key[pygame.K_RIGHT] or key[pygame.K_d]: # right key
            self.x += dist # move right
        elif key[pygame.K_LEFT] or key[pygame.K_a]: # left key
            self.x -= dist # move left


    def rotate(self, surface):

        keys = pygame.key.get_pressed()
        if keys[K_LSHIFT]:
            self.rotate_vel += 5
            self.image = pygame.transform.rotate(self.orig_image, self.rotate_vel)
            self.rect = self.image.get_rect(center=self.rect.center)
            surface.blit(self.image, self.rect)
        if keys[K_SPACE]:
            self.rotate_vel += -5
            self.image = pygame.transform.rotate(self.orig_image, self.rotate_vel)
            self.rect = self.image.get_rect(center=self.rect.center)
            surface.blit(self.image, self.rect)


    def update(self):
        self.movement()
        self.draw(screen)
        self.rotate(screen)



class Bullet(pygame.sprite.Sprite):
    def __init__(self, pos, angle):
        super().__init__()
        self.image = pygame.image.load('graphics/weapons/bullets/default_bullet.png')
        self.image = pygame.transform.rotate(self.image, angle)
        self.rect = self.image.get_rect(center = pos)
        self.speed = 25
        self.pos = pos
        self.dir_vec = pygame.math.Vector2()
        self.dir_vec.from_polar((self.speed, -angle))


    def update(self, screen):
        self.pos += self.dir_vec
        self.rect.center = round(self.pos.x), round(self.pos.y)



class Zombie(pygame.sprite.Sprite):
    def __init__(self, x , y):
        super().__init__()
        self.x = x
        self.y = y
        self.image = pygame.image.load('graphics/zombie/zoimbie1_hold.png').convert_alpha()
        self.rect = self.image.get_rect(center = (x,y))
        self.orig_image = pygame.image.load('graphics/Robot 1/robot1_gun.png').convert_alpha()

    def draw(self, surface):
        surface.blit(self.image, self.rect)

    def update(self):
        self.draw(screen)



#screen
clock = pygame.time.Clock()
FPS = 60
screen = pygame.display.set_mode((1200, 600))

#player
player_sprite = Player(600, 300)
player = pygame.sprite.GroupSingle()
player.add(player_sprite)

#bullet
bullet_group = pygame.sprite.Group()


#Zombie
zombie_sprite = Zombie(600, 300)
zombie = pygame.sprite.Group()
zombie.add(zombie_sprite)
#keys
keys = pygame.key.get_pressed()


running = True
while running:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()

        if event.type == pygame.MOUSEBUTTONDOWN:
            if event.button == 1:
                    pos = player_sprite.rect.center
                    new_bullet = Bullet(pos, player_sprite.rotate_vel)
                    bullet_group.add(new_bullet)

                   
                    


    if pygame.sprite.spritecollide(zombie_sprite,bullet_group , True):
                print('hello')
                

    bullet_group.update(screen)
    #screen
    screen.fill('grey')
    #player sprite funtions
    player.update() 
    #buller group draw
    bullet_group.draw(screen)
    bullet_group.update(screen) 
    #Zombie update
    zombie.update()  

    clock.tick(FPS)

    pygame.display.update()