pyqt5 中如何发 Post 请求， Python 版的

class MyNetworkTest(QMainWindow):
    def __init__(self, parent = None):
        super().__init__(parent)
        self.mywidget = testnetwork.Ui_MainWindow()
        self.mywidget.setupUi(self)
        self.mywidget.pushButton.clicked.connect(self.requestNetwork)

    def replyFinished(self, reply):
        pass
    
    def requestNetwork(self):
        httpReq = HttpReq()
        url = 'http://localhost:8021/api/v1/getDesignTool'
        data_dict = {'seqno': '10001'}
        httpReq.request(url, data_dict, self.request_success, self.request_error)


import sys
import json
import testnetwork

from PyQt5.QtWidgets import *
from PyQt5.QtNetwork import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *


class HttpReq(QObject):

    def __init__(self):
        super().__init__()
        self.onSuccess = None
        self.onFailed = None
        self.m_netAccessManager = QNetworkAccessManager()
        self.m_netReply = None

    def request(self, httpUrl, sendData, on_success, on_fail):
        if self.m_netReply is not None:
            self.m_netReply.disconnect()
        self.onSuccess = on_success
        self.onFailed = on_fail

        req = QNetworkRequest(QUrl( httpUrl))
        req.setHeader(QNetworkRequest.ContentTypeHeader, "application/x-www-form-urlencoded")
        senda = QByteArray()
        senda.append(self.convertDict(sendData))

        self.m_netAccessManager.finished.connect(self.readData)
        self.m_netReply = self.m_netAccessManager.post(req, senda)

        # eventloop = QEventLoop()
        # eventloop.exec()
        # QNetworkReply * postReply = m_pNetManager->post(request, qbt); // post 方式到本地服务器
        # connect(postReply, SIGNAL(finished()), this, SLOT(postFileReplyFinished())); // 成功后会有返回响应
        # loop->exec();

        # self.m_netReply.finished.connect(self.readData)
        # self.m_netReply.error.connect(self.requesterr)

    def readData(self):
        recvData = self.m_netReply.readAll()
        print(recvData)
        data = bytes.decode(recvData.data(), encoding='utf8')
        try:
            result = json.loads(data)
            self.onSuccess(result)
        except Exception as err:
            self.onFailed(err)

    def requesterr(self, err):
        self.onFailed(err)

    def convertDict(self, param_dict):
        param_str = ""
        index = 1
        for key, value in param_dict.items():
            if index == len(param_dict):
                param_str += '%s%s%s' % (key, '=', value)
            else:
                param_str = '%s%s%s%s' % (key, '=', value, '&')
            index += 1
        return param_str

发现不在主线程上 self.m_netAccessManager.finished.connect(self.readData) 的回调不会执行这个 QEventLoop 也不知道如何用，有用过 Pyqt5 开发的朋友提供下文章或者相关代码么，post 请求发文件和数据的相关的，谢谢