PyQt5 Label – Adding Opacity effect

In this article we will see how we can add opacity effect to the label by default there is no opacity effect to the label although we can create opacity effect for the label. Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc. Below is the representation of how label with opacity effect looks like

In order to do this we have to do the following –

1. Create a label
2. Set geometry to the label
3. Create a QGraphicsOpacityEffect object
4. Add this object to the label with the help of setGraphicsEffect method

Syntax :

# creating a opacity effect
opacity_effect = QGraphicsOpacityEffect()

# adding opacity effect to the label
label.setGraphicsEffect(opacity_effect)

Below is the implementation

# importing libraries
from PyQt5.QtWidgets import *
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys


class Window(QMainWindow):

    def __init__(self):
        super().__init__()

        # setting title
        self.setWindowTitle("Python ")

        # setting geometry
        self.setGeometry(100, 100, 600, 400)

        # calling method
        self.UiComponents()

        # showing all the widgets
        self.show()

    # method for widgets
    def UiComponents(self):

        # creating label
        label = QLabel("Label", self)

        # setting geometry to the label
        label.setGeometry(200, 100, 150, 60)

        # setting alignment to the label
        label.setAlignment(Qt.AlignCenter)

        # setting font
        label.setFont(QFont('Arial', 15))

        # setting style sheet of the label
        label.setStyleSheet("QLabel"
                            "{"
                            "border : 2px solid green;"
                            "background : lightgreen;"
                            "}")

        # creating a opacity effect
        self.opacity_effect = QGraphicsOpacityEffect()

        # setting opacity level
        self.opacity_effect.setOpacity(0.3)

        # adding opacity effect to the label
        label.setGraphicsEffect(self.opacity_effect)


# create pyqt5 app
App = QApplication(sys.argv)

# create the instance of our Window
window = Window()

# start the app
sys.exit(App.exec())

Output :