Pygame Multiplayer Bullet and Player Collision Checking

Ok, so i need a little bit of advice and help, im making a 2d Multiplayer FPS (first person shooter) game using pygame, threading and sockets (ill convert it to websockets later dw). and each client has a player class and the player has a list/dict of bullets the player shot then it sends it to the server

##################### CLIENT SIDE #####################
    r.clear() # r is a mutable data type aka list (its the only way to return values from threaded functions)
    b = []
    for bu in theply.bullets:
        bl = theply.bullets[bu]
        b.append({
            "id":str(bl.id),
            "x":float(bl.x),
            "y":float(bl.y),
            "x_vel":float(bl.x_vel),
            "y_vel":float(bl.y_vel),
            "angle":float(bl.angle),
            })
    req = {
        "id":str(theply.id),
        "color":theply.color,
        "name":str(theply.name),
        "x":float(theply.x),
        "y":float(theply.y),
        "reload_": int(theply.reload_),
        "bullets": b
    }
    r.append(send(req)) # return and sends the msg to the server, the func send returns values from the server and my code later takes r[0] as return value of the threaded func

And the Server takes the player and send all game objects back:-

##################### SERVER SIDE #####################
def R(msg):
    if msg == "reset":
            GAME.clear()
            GAME["players"] = dict()
            return True
    else:
        b = dict()
        for i in msg["bullets"]:
            b[i["id"]] = {
            "x":i["x"],
            "y":i["y"],
            "x_vel":i["x_vel"],
            "y_vel":i["y_vel"],  
            "angle":i["angle"]
            }
        GAME["players"][msg["id"]] = {
            "color":msg["color"],
            "name":msg["name"],
            "x":msg["x"],
            "y":msg["y"],
            "reload_":msg["reload_"],
            "bullets":b,

        }
        return GAME

Also both the player and bullets have their own Pygame Rectangles, so where should i check the bullet collision? using these -

pygame.Rect.colliderect
# OR
pygame.Rect.collidelist

• a) the player checks all the other player bullets if they have hit it
• b) the player who shoots the bullets, checks if his bullets have hit others
• c) do the colision server side (not possible bcs the pygame lib cant check colision without window)
• d) whatever you guys suggest