急求大佬指导grpc python进行安全连接的代码（有PHP版本的代码，改写成python）

急求大佬，我现在在用python写grpc的客户端，用来获取数据提供商的股票数据。提供商只给了我一个PHP版本的代码用作指导，但是我需要用python写。其他地方都没有问题了，只有安全连接这个部分卡住了，查了两天也没查到解决办法。。用了好几种api可是都不行。情况就是有url,端口，.pem格式的证书以及账号和密码。大概的思路应该是在建立channel的时候带入额外的账号密码等信息？
求大佬帮忙看看用python怎么写呢。。跪谢大佬了！

下面为php代码：

下面为我写的不好用的python代码：

 from __future__ import print_function

import grpc

import historicalQuote_pb2
import historicalQuote_pb2_grpc
import common_pb2
import common_pb2_grpc
import marketData_pb2
import marketData_pb2_grpc

import os

from google import auth as google_auth
from google.auth.transport import grpc as google_auth_transport_grpc
from google.auth.transport import requests as google_auth_transport_requests

def run():
    symbol = common_pb2.Symbol()
    symbol.code = "BABA"
    symbol.market = common_pb2.US
    symbol.type = common_pb2.Stock

    market_request = marketData_pb2.MarketDataRequest()
    market_request.symbol.code = symbol.code
    market_request.symbol.market = symbol.market
    market_request.symbol.type = symbol.type
    market_request.language = common_pb2.zhHans

    print(market_request)

    try:
        path = os.path.abspath('.')
        pemPath = path + '/open_test_cert.pem'
        transport_creds = grpc.ssl_channel_credentials(open(pemPath).read())
        options = []
        update_metadata = {}
        update_metadata2 = {}

        update_metadata['UserName'] = 'xxxx'
        update_metadata['Password'] = 'yyyy'
        update_metadata2['grpc.ssl_target_name_override'] = 'open.test.yintongzhibo.com'
        options.append(update_metadata)
        # options.append(update_metadata2)
        channel = grpc.secure_channel("open.test.yintongzhibo.com:9002",transport_creds,options)



        # credentials , project= google_auth.default(scopes=(scope1,scope2,scope3))
        # credentials , project= google_auth.default()
        # http_request = google_auth_transport_requests.Request()
        # metadata_plugin = AuthMetadataPlugin(credentials,http_request)
        # google_auth_credentials = grpc.metadata_call_credentials(metadata_plugin)
        # ssl_credentials = grpc.ssl_channel_credentials(open(pemPath).read())
        # composite_credentials = grpc.composite_channel_credentials(ssl_credentials,google_auth_credentials)
        # channel = grpc.secure_channel("open.test.yintongzhibo.com:9002",composite_credentials)
        # channel = google_auth_transport_grpc.secure_authorized_channel(credentials,request,'open.test.yintongzhibo.com:9002')



        stub = historicalQuote_pb2_grpc.HistoricalQuoteServiceStub(channel)
        response = stub.getTodayM1Quotes(symbol)
        # stub = marketData_pb2_grpc.MarketDataServiceStub(channel)
        # response = stub.getMarketData(market_request)
        print(response.message)

    except Exception as e:
        print (e)



if __name__ == '__main__':
  run()

求大佬啊。。。。。。。。。。。。。。。。。

https://github.com/grpc/grpc.github.io/blob/master/docs/guides/auth.md#extending-grpc-to-support-other-authentication-mechanisms

你好，我用你发的这个php版本的代码进行grcp的安全连接却不能连接上。能帮我看下吗

$di->setShared('grpc', function () {
    require ZPT_PATH . '/vendor/autoload.php';
    $config = $this->getConfig();
    $grpc_config =  $config->grpc->host. ':' .$config->grpc->port;
    $credentials = Grpc\ChannelCredentials::createSsl(file_get_contents(dirname(__FILE__) . '/zuopintong_com.crt'));

    $client = new Zpt\BaseClient($grpc_config,[
        'credentials' => $credentials,
        'grpc.ssl_target_name_override' => 'grpc.zuopintong.com',
        ]);
//    var_dump($client);die;
    return $client;
});