How to update label in Qt?

Question

Python

When the stream starts, the window is blocked and the label is not updated.

def start(self):
        print('Stream Strat')
        self.widget_stream.clear()
        response = requests.post('http://192.168.122.1:8080/sony/camera', json={"method": "startLiveview","params": [],"id": 1,"version": "1.0" })
        print(response.content)
        response = requests.get('http://192.168.122.1:8080/liveview/liveviewstream', stream=True)
        for line in response.iter_content(chunk_size=1024*1024):
            if line.find(b'\xff\xd8') != -1 and line.find(b'\xff\xd9') != -1:
                b_jpeg_s = line.find(b'\xff\xd8')
                b_jpeg_e = line.find(b'\xff\xd9')
                image_bmp = Image.open(io.BytesIO(line[b_jpeg_s:b_jpeg_e + 2]))
                image_bmp.save('image.bmp')
                pixmap = QPixmap('image.bmp')
                self.label_image.setPixmap(pixmap)

How to make the label update regularly. (A byte stream comes from the server, which is converted into an image, and then must be inserted into the label)

Answer 1

I can't upload the image in your way

import io
import sys
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
import requests


def log_uncaught_exceptions(ex_cls, ex, tb):
    text = '{}: {}:\n\n'.format(ex_cls.__name__, ex)
    import traceback
    text += ''.join(traceback.format_tb(tb))

    QMessageBox.critical(None, 'Ошибка!', text)
    quit()

sys.excepthook = log_uncaught_exceptions


class SenderMessage(QObject):
    image_bytes = pyqtSignal(bytes)

    def __init__(self):
        super().__init__()

    @pyqtSlot()
    def run(self):
        image_bytes = requests.get('https://dadaviz.ru/wp-content/uploads/2018/02/1-12.jpg', stream=True).content
        self.image_bytes.emit(image_bytes)

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):

        self.setWindowTitle("Показать изображение")
        self.setGeometry(400, 200, 626, 626)

        self.label_image = QLabel(self)
        self.label_image.setGeometry(0, 0, 626, 626)

        self.pixmap = QPixmap()

        self.thread = QThread()

        self.sender_message = SenderMessage()

        self.sender_message.moveToThread(self.thread)
        self.sender_message.image_bytes.connect(self.signalHandlerImageBytes)


        self.thread.started.connect(self.sender_message.run)
        self.thread.start()

    def signalHandlerImageBytes(self, image_bytes):
        self.pixmap.loadFromData(image_bytes)
        self.label_image.setPixmap(self.pixmap)

def main():
    app = QApplication(sys.argv)
    main_window = MainWindow()
    main_window.show()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

Answer 2

You don't have time to process the event queue and redraw widgets. Second thread on QThread or QRunnable, send signals from it with new data.