[FIXED] how to add color, background-color value through variable in PyQt5?

Issue

Its my code. How to assign the values for CSS through variable and the use same in PyQt5 stylesheet ?

    self.label = QLabel("sample")
    self.label.setObjectName("label_1")
    self.label.setStyleSheet(my_stylesheet())

def my_stylesheet():
    return """
    QLabel#label_1{color:red;background-color:blue;}
    """

Instead of direct values (like red, blue), assign it in a variable and how to use it. For ex :

color_1 =red
color_2 = blue
QLabel#label_1{"color:color_1; background-color:color_2;}

Solution

A possible solution is to use property where the Qt stylesheet change is applied in the setter:

import sys

from PyQt5.QtCore import Qt
from PyQt5.QtGui import QColor, QFont
from PyQt5.QtWidgets import QApplication, QLabel, QMainWindow


class Label(QLabel):
    def __init__(
        self, background=QColor("white"), foreground=QColor("black"), parent=None
    ):
        super().__init__(parent)
        self._background = background
        self._foreground = foreground

        self._change_stylesheet()

    @property
    def background(self):
        return self._background

    @background.setter
    def background(self, color):
        if self._background == color:
            return
        self._background = color
        self._change_stylesheet()

    @property
    def foreground(self):
        return self._foreground

    @foreground.setter
    def foreground(self, color):
        if self._foreground == color:
            return
        self._foreground = color
        self._change_stylesheet()

    def _change_stylesheet(self):
        qss = "QLabel{color:%s;background-color:%s}" % (
            self.background.name(),
            self.foreground.name(),
        )
        self.setStyleSheet(qss)


if __name__ == "__main__":
    app = QApplication(sys.argv)

    label = Label()
    label.setText("Qt is awesome!!!")
    label.setAlignment(Qt.AlignCenter)
    label.setFont(QFont("Arial", 40))

    label.background = QColor("red")
    label.foreground = QColor("blue")

    w = QMainWindow()
    w.setCentralWidget(label)
    w.resize(640, 480)
    w.show()

    sys.exit(app.exec_())

Answered By - eyllanesc