Source Code: Creating an Image Compression App with Python | Full Tutorial

import sys
import json
import os
from PyQt5.QtWidgets import QApplication, QWidget, QListWidget, QListWidgetItem, QLabel, QLineEdit, QPushButton, QSizePolicy, \
                            QAbstractItemView, QHBoxLayout, QVBoxLayout, QLayout
from PyQt5.QtCore import Qt, QRectF, QThread, pyqtSignal
from PyQt5.QtGui import QIcon
import tinify # pip install tinify

def compress_image(image_source, output_file_path):
    try:
        image_file_name = os.path.basename(image_source)
        source = tinify.from_file(image_source)
    except tinify.errors.AccountError:
        return (False, 'Invalid API Key')
    except tinify.errors.ConnectionError as e:
        return (False, str(e))
    except tinify.errors.ClientError:
        return (False, 'File type is not supported')
    else:
        source.to_file(output_file_path)
        return (True, 'Ok')


class MyApp(QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('TinyPNG Image Compressor')
        self.setWindowIcon(QIcon('1343439.ico'))
        self.window_width, self.window_height = 1800, 800
        self.setMinimumSize(self.window_width, self.window_height)

        self.layout = QVBoxLayout()
        self.setLayout(self.layout)

        self.layoutRow1 = QHBoxLayout()
        self.layoutRow1.setSizeConstraint(QLayout.SetFixedSize)
        self.layout.addLayout(self.layoutRow1)

        # label
        labelPath = QLabel('&Export To: ')
        labelPath.setStyleSheet('font-size: 30px')
        self.layoutRow1.addWidget(labelPath)

        # folder path to export image files
        self.export_path = QLineEdit()
        self.export_path.setAlignment(Qt.AlignLeft)
        self.export_path.setMinimumHeight(50)
        self.export_path.setText(os.getcwd())
        self.layoutRow1.addWidget(self.export_path)

        # assign shortcut
        labelPath.setBuddy(self.export_path)


        # sublayout #2
        self.layoutRow2 = QHBoxLayout()
        self.layout.addLayout(self.layoutRow2)

        self.initColumnA()
        self.initColumnB()

    def resetFields(self):
        self.listFiles.clear()
        self.status.clear()
        self.export_path.setText(os.getcwd())

    def initColumnA(self):
        layoutColumnA = QVBoxLayout()
        self.layoutRow2.addLayout(layoutColumnA, 8)

        # list widget
        self.listFiles = ImageListWidget()
        layoutColumnA.addWidget(self.listFiles)

        # status label
        self.status = QLabel()
        layoutColumnA.addWidget(self.status)

    def initColumnB(self):
        layoutColumnB = QVBoxLayout()
        self.layoutRow2.addLayout(layoutColumnB)

        # push buttons
        self.btnConvert = QPushButton('&Convert', clicked=self.compressImages)
        self.btnConvert.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)

        self.btnReset = QPushButton('&Reset', clicked=self.resetFields)
        self.btnReset.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)

        self.btnClose = QPushButton('C&lose', clicked=app.quit)
        self.btnClose.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)       

        layoutColumnB.addWidget(self.btnConvert)
        layoutColumnB.addWidget(self.btnReset)
        layoutColumnB.addWidget(self.btnClose)
        layoutColumnB.addStretch()

    def compressImages(self):
        self.output_path = self.export_path.text()

        if not os.path.isdir(self.output_path):
            self.status.setText('Invalid Directory')
            return
        elif self.listFiles.count() == 0:
            self.status.setText('0 File')
            return

        self.worker = CompressImage(self)

        try:
            self.worker.finished.connect(self.threadFinished)
            self.worker.progress.connect(lambda v: self.status.setText('Prcessing {0}'.format(v)))
            self.worker.started.connect(self.threadStarted)
            self.worker.start()

        except Exception as e:
            self.status.setText(str(e))

    def threadStarted(self):
        self.btnConvert.setEnabled(False)
        self.btnReset.setEnabled(False)
        self.btnClose.setEnabled(False)

    def threadFinished(self):
        self.btnConvert.setEnabled(True)
        self.btnReset.setEnabled(True)
        self.btnClose.setEnabled(True)


class CompressImage(QThread):
    progress = pyqtSignal(str)

    def __init__(self, parent=None):
        super().__init__()
        self.parent = parent

    def run(self):
        for i in range(self.parent.listFiles.count()-1, -1, -1):
            source_file = self.parent.listFiles.item(i).text()
            file_basename = os.path.basename(source_file)
            self.progress.emit(file_basename)

            response = compress_image(source_file, os.path.join(self.parent.output_path, file_basename))
            if response[1] != 'Ok':
                self.parent.status.setText(response[1])
                self.terminate()
            else:
                self.parent.listFiles.model().removeRow(i)


class ImageListWidget(QListWidget):
    def __init__(self, parent=None):
        super().__init__(parent=None)
        self.setStyleSheet('font-size: 30px;')
        self.setAcceptDrops(True)
        self.setDragDropMode(QAbstractItemView.InternalMove)
        self.setSelectionMode(QAbstractItemView.ExtendedSelection)

    def dragEnterEvent(self, event):
        if event.mimeData().hasUrls():
            event.accept()
        else:
            return super().dragEnter(event)

    def dragMoveEvent(self, event):
        if event.mimeData().hasUrls():
            event.setDropAction(Qt.CopyAction)
            event.accept()
        else:
            return super().dragMoveEvent(event)

    def dropEvent(self, event):
        if event.mimeData().hasUrls():
            event.setDropAction(Qt.CopyAction)
            event.accept()

            images = []

            for url in event.mimeData().urls():
                if url.isLocalFile():
                    if url.toString().endswith(('.jpeg', '.jpg', '.png')):
                        images.append(str(url.toLocalFile()))
            self.addItems(images)
        else:
            super().dropEvent(event)


if __name__ == '__main__':
    # don't auto scale when drag app to a different monitor.
    # QApplication.setAttribute(Qt.HighDpiScaleFactorRoundingPolicy.PassThrough)
    
    api_key = json.load(open('api_key.json'))
    tinify.key = api_key['key']

    app = QApplication(sys.argv)
    app.setStyle('fusion')
    app.setStyleSheet('''
        QWidget {
            font-size: 30px;
            background-color: #3F3F5E
        }
        QPushButton {
            width: 240px;
            height: 60px;
            background-color: #565880;
            color: #FFFFFF;
            border-radius: 10px;
        }
        QListWidget {
            background-color: #FFFFFF;
        }
        QLabel {
            color: #FFFFFF;
        }
        QLineEdit {
            background-color: #FFFFFF;
        }
    ''')
    
    myApp = MyApp()
    myApp.show()

    try:
        sys.exit(app.exec_())
    except SystemExit:
        print('Closing Window...')