Rock, Paper and scissors

import random

def rock_paper_scissors():
    choices = ["rock", "paper", "scissors"]
    while True:
        user = input("Choose rock, paper, or scissors: ").lower()
        if user not in choices:
            print("Invalid choice.")
            continue
        computer = random.choice(choices)
        print(f"Computer chose {computer}.")
        if user == computer:
            print("Tie!")
        elif (user == "rock" and computer == "scissors") or (user == "paper" and computer == "rock") or (user == "scissors" and computer == "paper"):
            print("You win!")
        else:
            print("You lose!")
        if input("Play again? (y/n): ").lower() != "y":
            break

rock_paper_scissors()