PyQt5 – How to change border style of MainWindow ?

When we create a window in PyQt5, by default, there is no special type of border to it. But we change the style, thickness as well as color of the main window by using setStyleSheet() method.

Below is how normal border vs styled border looks like

Syntax : self.setStyleSheet(“border : 3px dashed blue;”)

Argument: It takes string as argument.
"border : size_of_border type_of_border color_of_border;"

Action performed : It sets the border style.

Code :

# importing the required libraries

from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
import sys


class Window(QMainWindow):
    def __init__(self):
        super().__init__()


        # set the title
        self.setWindowTitle("Python")

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

        # setting up the style of border
        self.setStyleSheet("border : 3px dashed blue;")

        # creating a label widget
        self.label_1 = QLabel("new border ", self)

        # moving position
        self.label_1.move(100, 100)

        # setting up the border
        self.label_1.setStyleSheet("border :3px solid black;")

        # show all the widgets
        self.show()


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

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

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

Output :