# 📚 PyQt5 Tutorial - Part 5/6: Networking, Multimedia & Internationalization
#PyQt5 #Networking #Multimedia #i18n #Deployment

Welcome to Part 5 of our PyQt5 series! This comprehensive lesson covers professional networking, multimedia handling, internationalization, and deployment strategies for production applications.

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## 🔹 Networking with PyQt5
### 1. HTTP Requests with QNetworkAccessManager

from PyQt5.QtNetwork import QNetworkRequest, QNetworkAccessManager
from PyQt5.QtCore import QUrl

class ApiClient(QObject):
    response_received = pyqtSignal(str)
    error_occurred = pyqtSignal(str)

    def __init__(self):
        super().__init__()
        self.manager = QNetworkAccessManager()
        self.manager.finished.connect(self.handle_response)

    def fetch_data(self, url):
        request = QNetworkRequest(QUrl(url))
        self.manager.get(request)

    def handle_response(self, reply):
        if reply.error():
            self.error_occurred.emit(reply.errorString())
        else:
            data = reply.readAll().data().decode('utf-8')
            self.response_received.emit(data)
        reply.deleteLater()

# Usage
client = ApiClient()
client.response_received.connect(lambda data: print("Received:", data))
client.error_occurred.connect(lambda err: print("Error:", err))
client.fetch_data("https://api.example.com/data")

### 2. WebSocket Communication

from PyQt5.QtWebSockets import QWebSocket

class WebSocketClient(QObject):
    message_received = pyqtSignal(str)
    connected = pyqtSignal()
    disconnected = pyqtSignal()

    def __init__(self):
        super().__init__()
        self.socket = QWebSocket()
        self.socket.textMessageReceived.connect(self.message_received)
        self.socket.connected.connect(self.connected)
        self.socket.disconnected.connect(self.disconnected)

    def connect_to_server(self, url):
        self.socket.open(QUrl(url))

    def send_message(self, message):
        self.socket.sendTextMessage(message)

# Usage
ws_client = WebSocketClient()
ws_client.connect_to_server("ws://echo.websocket.org")
ws_client.iss.onessage_received.connect(print)

### 3. TCP Socket Server

from PyQt5.QtNetwork import QTcpServer, QTcpSocket

class TcpServer(QObject):
    new_connection = pyqtSignal(QTcpSocket)

    def __init__(self):
        super().__init__()
        self.server = QTcpServer()
        self.server.newConnection.connect(self.handle_new_connection)

    def start(self, port=12345):
        if not self.server.listen(QHostAddress.Any, port):
            print("Server error:", self.server.errorString())
            return False
        print(f"Server started on port {port}")
        return True

    def handle_new_connection(self):
        client = self.server.nextPendingConnection()
        client.readyRead.connect(lambda: self.read_data(client))
        client.disconnected.connect(client.deleteLater)
        self.new_connection.emit(client)

    def read_data(self, client):
        data = client.readAll().data().decode('utf-8')
        print("Received:", data)
        client.write(f"Echo: {data}".encode())

---

## 🔹 Practical Example: Weather App

class WeatherApp(QMainWindow):
    def __init__(self):
        super().__init__()
        self.api_key = "YOUR_API_KEY"
        self.setup_ui()
        self.setup_network()
    
    def setup_ui(self):
        self.setWindowTitle(self.tr("Weather App"))
        
        # Location Input
        self.location_input = QLineEdit()
        search_btn = QPushButton(self.tr("Search"))
        search_btn.clicked.connect(self.fetch_weather)
        
        # Weather Display
        self.weather_icon = QLabel()
        self.weather_icon.setAlignment(Qt.AlignCenter)
        
        self.temp_label = QLabel()
        self.temp_label.setAlignment(Qt.AlignCenter)
        font = self.temp_label.font()
        font.setPointSize(48)
        self.temp_label.setFont(font)
        
        self.details_label = QLabel()
        self.details_label.setAlignment(Qt.AlignCenter)
        
        # Layout
        input_layout = QHBoxLayout()
        input_layout.addWidget(self.location_input)
        input_layout.addWidget(search_btn)
        
        main_layout = QVBoxLayout()
        main_layout.addLayout(input_layout)
        main_layout.addWidget(self.weather_icon)
        main_layout.addWidget(self.temp_label)
        main_layout.addWidget(self.details_label)
        
        container = QWidget()
        container.setLayout(main_layout)
        self.setCentralWidget(container)
    
    def setup_network(self):
        self.manager = QNetworkAccessManager()
        self.manager.finished.connect(self.handle_weather_response)
        
        self.icon_manager = QNetworkAccessManager()
        self.icon_manager.finished.connect(self.handle_icon_response)
    
    def fetch_weather(self):
        location = self.location_input.text()
        if not location:
            return
            
        url = f"https://api.openweathermap.org/data/2.5/weather?q={location}&appid={self.api_key}&units=metric"
        self.manager.get(QNetworkRequest(QUrl(url)))
    
    def handle_weather_response(self, reply):
        if reply.error():
            QMessageBox.warning(self, self.tr("Error"), 
                              self.tr("Failed to fetch weather data"))
            return
            
        data = json.loads(reply.readAll().data().decode('utf-8'))
        
        # Update UI
        temp = data['main']['temp']
        self.temp_label.setText(f"{temp}°C")
        
        description = data['weather'][0]['description'].capitalize()
        humidity = data['main']['humidity']
        wind = data['wind']['speed']
        self.details_label.setText(
            self.tr(f"{description}\nHumidity: {humidity}%\nWind: {wind} m/s"))
        
        # Fetch weather icon
        icon_code = data['weather'][0]['icon']
        icon_url = f"https://openweathermap.org/img/wn/{icon_code}@2x.png"
        self.icon_manager.get(QNetworkRequest(QUrl(icon_url)))
    
    def handle_icon_response(self, reply):
        if not reply.error():
            pixmap = QPixmap()
            pixmap.loadFromData(reply.readAll())
            self.weather_icon.setPixmap(pixmap.scaledToWidth(100))

---

## 🔹 Best Practices
1. Handle network errors gracefully - Always check reply.error()
2. Clean up resources - Call deleteLater() on network objects
3. Cache API responses - Reduce unnecessary network calls
4. Use QThread for intensive operations - Keep UI responsive
5. Test translations thoroughly - Verify all UI elements adapt

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### 📌 What's Next?
In Final Part 6, we'll cover:
➡️ Advanced Architecture Patterns
➡️ Plugin Systems
➡️ Performance Optimization
➡️ Cross-Platform Considerations

#PyQt5 #Networking #Multimedia #Deployment 🚀

Practice Exercise:
1. Build a podcast player with download capability
2. Create a multilingual chat application
3. Implement an auto-updating stock ticker