import sysfrom PyQt5.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout, QFrame, QScrollArea, QHBoxLayout) app = QApplication(sys.argv)layout = QVBoxLayout()b_widget=QWidget()b_widget.setStyleSheet("background-color: blue") r_widget=QWidget()r_widget.setStyleSheet("background-color: red") g_widget=QWidget()g_widget.setStyleSheet("background-color: green") scroll=QScrollArea()scroll.setWidget(g_widget) layout.addWidget(scroll)layout.addWidget(r_widget)layout.addWidget(g_widget) widget = QWidget()widget.setLayout(layout) main=QMainWindow()main.setCentralWidget(widget) main.show() app.exec()