3.猜拳游戏：石头、剪刀、布的游戏

##不用render_template函数，把html代码放在py文件里，不用单独写html文件
from flask import Flask, request
import random

app = Flask(__name__)

@app.route('/')
def index():#下面form标签虽然放在注释里，但是是可以读取的html内容
    return '''
    <form method="POST" action="/play">
        <label>出拳输入：1石头，2剪刀，3布：</label>
        <input type="text" name="user_input">
        <input type="submit" value="提交">
    </form>
    '''

@app.route('/play', methods=['POST'])
def play():
    computer = random.randint(1, 3)
    user_input = request.form['user_input']#直接从form标签下 input里拿值
    try:
        n = int(user_input)
        if n == computer:
            return f'平局,对方{computer}'
        elif (n == 1 and computer == 2) or (n == 2 and computer == 3) or (n == 3 and computer == 1):
            return f'你赢了！！,对方{computer}'
        elif n >= 4:
            return f'请出123石头剪刀布！！,对方{computer}'
        elif user_input == '':
            return '请出拳！'
        elif n == 0:
            return '游戏结束！！'
        else:
            return f'你输了！！,对方{computer}'
    except ValueError:
        return '请重新输入123或输入0退出：'

if __name__ == '__main__':
    app.run()