小程序授权登录，前后端代码

前端代码：

1. 引入wx.login()获取code

wx.login({
  success: res => {
    const code = res.code;
    // 发送到后端进行授权登录
    wx.request({
      url: 'https://example.com/api/login',
      method: 'POST',
      data: { code },
      success: res => {
        // 授权成功后的操作
      }
    })
  }
})

2. 调用授权按钮

<view>
  <button open-type="getUserInfo" bindgetuserinfo="getUserInfo">授权登录</button>
</view>

3. 获取用户信息

getUserInfo: function (e) {
  const userInfo = e.detail.userInfo;
  // 发送到后端进行授权登录
  wx.request({
    url: 'https://example.com/api/login',
    method: 'POST',
    data: { userInfo },
    success: res => {
      // 授权成功后的操作
    }
  })
}

后端代码：

1. 获取code或用户信息，向微信服务器发送请求获取session_key和openid

from urllib import request
import json

def get_session_key(code):
    appid = 'your_appid'
    secret = 'your_secret'
    url = f'https://api.weixin.qq.com/sns/jscode2session?appid={appid}&secret={secret}&js_code={code}&grant_type=authorization_code'
    with request.urlopen(url) as f:
        data = f.read().decode('utf-8')
        return json.loads(data)

2. 将session_key和openid存储到数据库中，并返回用户的token

import jwt

def login(request):
    if request.method == 'POST':
        data = json.loads(request.body)
        code = data.get('code')
        userInfo = data.get('userInfo')
        if code:
            session_key = get_session_key(code).get('session_key')
            openid = get_session_key(code).get('openid')
            # 将session_key和openid存储到数据库中
            token = jwt.encode({'openid': openid}, 'your_secret_key').decode()
            return JsonResponse({'token': token})
        elif userInfo:
            # 获取用户信息，生成token并返回
            openid = 'get_from_database'
            token = jwt.encode({'openid': openid}, 'your_secret_key').decode()
            return JsonResponse({'token': token})
    return HttpResponse('Unauthorized', status=401)

3. 验证token是否有效

import jwt

def auth_required(func):
    def wrapper(request, *args, **kwargs):
        try:
            token = request.headers.get('Authorization').split(' ')[1]
            payload = jwt.decode(token, 'your_secret_key')
            openid = payload.get('openid')
            # 根据openid进行操作
            return func(request, *args, **kwargs)
        except:
            return HttpResponse('Unauthorized', status=401)
    return wrapper