写一个石头剪刀布的Python代码

import random

print("欢迎来玩石头剪刀布游戏！")
print("请输入您的选择：")
print("1. 石头 2. 剪刀 3. 布")

player_choice = int(input())

if player_choice not in [1, 2, 3]:
    print("请输入有效数字！")
else:
    computer_choice = random.randint(1, 3)
    print("电脑选择了：", computer_choice)

    if player_choice == computer_choice:
        print("平局！")
    elif player_choice == 1 and computer_choice == 2:
        print("您赢了！")
    elif player_choice == 2 and computer_choice == 3:
        print("您赢了！")
    elif player_choice == 3 and computer_choice == 1:
        print("您赢了！")
    else:
        print("电脑赢了！")

注意：上述代码是基于Python 3的，如果是Python 2的话需要做一些修改，比如input()函数应改为raw_input()函数。