upload.py

import os
import sys

import boto3
from PySide2.QtCore import QRunnable, QObject, QThreadPool, Signal, Slot
from PySide2.QtWidgets import QMainWindow, QVBoxLayout, QProgressBar, QPushButton, QWidget, QApplication


class TestWindow(QMainWindow):

    def __init__(self):
        super(TestWindow, self).__init__()
        self.tasks = Tasks(parent=self)
        layout = QVBoxLayout()
        self.bar = QProgressBar()
        self.button = QPushButton('upload')
        self.button.pressed.connect(self.execute)
        w = QWidget()
        layout.addWidget(self.bar)
        layout.addWidget(self.button)
        w.setLayout(layout)
        self.setCentralWidget(w)

    def execute(self):
        self.tasks.start()

    @Slot(int)
    def track_progress(self, value):
        self.bar.setValue(value)
        if value != 100:
            self.button.setDisabled(True)
            self.button.setText("upload in progress...")


class Worker(QRunnable):
    def __init__(self, parent=None):
        super(Worker, self).__init__()
        self.signals = Communicate()
        self.parent = parent
        self.signals.progress.connect(self.parent.track_progress)
        self.s3 = boto3.client(
            's3',
            aws_access_key_id='sssss',
            aws_secret_access_key='s++s/s',
            region_name='eu-lol-1')
        self.uploaded = 0
        self.progress = 0
        self.total = 0

    def upload_callback(self, size):
        if self.total == 0:
            return
        self.uploaded += size
        self.progress = int(self.uploaded / self.total * 100)
        self.signals.progress.emit(self.progress)

    def run(self):
        self.total = os.stat('file.pdf').st_size
        with open('file.pdf', 'rb') as data:
            self.s3.upload_fileobj(data, 'files', 'magic1', Callback=self.upload_callback)


class Tasks(QObject):
    def __init__(self, parent):
        super(Tasks, self).__init__()
        self.parent = parent
        self.pool = QThreadPool()
        self.pool.setMaxThreadCount(4)

    def start(self):
        worker = Worker(parent=self.parent)
        self.pool.start(worker)


class Communicate(QObject):
    progress = Signal(int)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = TestWindow()
    window.show()
    app.exec_()