Python 3 套接字和 QTcpsocket (c++) 之间的通信失败

当前使用 Qt 的 QTcpsocket 库和 python 3 的套接字类。我已经得到了 Qt 的 C++ Fortune 客户端/服务器示例来正确构建和运行。但是，它适用于都是 C++ 的客户端和服务器。要求是服务器正在运行 Python。

# Server.py


import socket

# ...
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(("localhost", 45000)
sock.listen(1) # queuing up 1 request for now.

(clientsocket, address) = sock.accept() # waits until client connects.

chunk = clientsocket.recv(1024).decode() # client is now connect
print(chunk) #prints out message from client

msg = "Hello from the server"
msg = str.encode(msg)

# send the message back to the client
clientsocket.sendall(msg)

和

// Client.h

#ifndef CLIENT_H
#define CLIENT_H
#include <QObject>
#include <QtNetwork/QtNetwork>

class Client : public QObject {
     Q_OBJECT
public:
     Client();
     QTcpSocket *m_socket;
     QHostAddress m_serverAddr = QHostAddress("127.0.0.1");
     quint16 m_serverPort = 45000;
private:
     QDataStream m_dataStream;
     void testConnect();
};
#endif

和

// client.cpp

Client::Client() {
    m_socket = new QTcpSocket(this);
    m_dataStream.setDevice(m_socket);
    m_dataStream.setVersion(QDataStream::Qt_4_0);
    testConnect();

}

void Client::testConnect() {
        m_socket->abort(); // if m_socket is not already connected, this does nothing
        m_socket->connectToHost(m_serverAddr, m_serverPort);
        if (m_socket->waitForConnected(30000)) {
            qDebug() << "Connected to server...";
            m_socket->write("Hello server from client"); // is received!
            m_socket->waitForBytesWritten();
            m_socket->waitForReadyRead();
            qDebug() << "Reading: " << m_socket->bytesAvailable();
            m_dataStream.startTransaction();
            QString nextFortune;
            m_dataStream >> nextFortune;
            if (!m_dataStream.commitTransaction()) {
                qDebug() << "Read errors have occurred."; // prints when connected to python server. not desired behavior
                m_socket->close();  
                return;              

            }
            // This prints when running the Qt fortune c++ server, but not the python server (above).
            qDebug() << "No read errors occurred during read transactions.";
            qDebug() << nextFortune;
        }

}

最终发生的是服务器毫无问题地从客户端接收消息，但是当服务器尝试使用 发送回复时clientsocket.sendall(msg)，m_dataStream.commitTransaction()返回false。我最初的直觉是 python 端的编码是错误的。QDataStream 是否需要特殊编码？

QDataStream::commitTransaction() 的文档：

bool QDataStream::commitTransaction()

完成一个读事务。true如果在事务期间没有发生读取错误，则返回；否则返回false。

此外，运行后，这里是 C++ 客户端的输出：

Connected to server...
Reading: 25
Read errors have occurred.