PyQt 5 pyqtProperty QSS example

widget.py

#!/usr/bin/env python3
from PyQt5.QtCore import QRect, pyqtProperty
from PyQt5.QtGui import QPaintEvent, QPainter, QColor, QPen
from PyQt5.QtWidgets import QWidget
from PyQt5.QtCore import Qt


class Widget(QWidget):
    """
    https://www.riverbankcomputing.com/static/Docs/PyQt5/qt_properties.html
    """
    def __init__(self):
        super().__init__()

        self.color = QColor("red")
        
	self.setStyleSheet("""
        Square {
            qproperty-textcolor: blue;
        }
        """)

    @pyqtProperty('QColor')
    def textcolor(self):
        return self.color

    @acolor.setter
    def textcolor(self, value):
        self.color = value

    def paintEvent(self, event: QPaintEvent) -> None:
        painter = QPainter(self)
        pen = QPen()
        pen.setColor(self.textcolor)
        painter.setPen(pen)
        rect = QRect(0, 0, painter.device().width(), painter.device().height())
        painter.drawRect(rect)