Styling with classes in Pyside + Python
Question: How can I better style this app using classes rather than redefining the same
styles for every label that should look the same. It makes it a pain to change
a style because I then have to go through every label that is suppose to look
the same and paste the code to match.

    
    
    #!/usr/bin/python
    # -*- coding: utf-8 -*-
    
    import sys
    from PySide import QtGui, QtCore
    
    class Example(QtGui.QWidget):
    
        def __init__(self):
            super(Example, self).__init__()
    
            self.initUI()
    
        def initUI(self):
    
            #Add all GUI Elements to Class
            self.amountLabel = QtGui.QLabel('Amount')
            self.counterLabel = QtGui.QLabel('Counter')
            self.totalLabel = QtGui.QLabel('Total')
            self.amountSpin = QtGui.QSpinBox()
            self.counterSpin = QtGui.QSpinBox()
    
            self.totalOutput = QtGui.QLabel('0')
    
            grid = QtGui.QGridLayout()
            grid.setSpacing(0)
    
            grid.addWidget(self.amountLabel, 3, 0)
            grid.addWidget(self.counterLabel, 3, 1)
            grid.addWidget(self.totalLabel, 3, 2)
    
            grid.addWidget(self.amountSpin, 4, 0)
            grid.addWidget(self.counterSpin, 4, 1)
            grid.addWidget(self.totalOutput, 4, 2)
    
            self.setLayout(grid)
    
            # STYLING
            self.amountLabel.setStyleSheet("QLabel { color: rgb(50, 50, 50); font-size: 11px; background-color: rgba(188, 188, 188, 50); border: 1px solid rgba(188, 188, 188, 250); }")
            self.amountSpin.setStyleSheet("QSpinBox { color: rgb(50, 50, 50); font-size: 11px; background-color: rgba(255, 188, 20, 50); }")
    
            self.counterLabel.setStyleSheet("QLabel { color: rgb(50, 50, 50); font-size: 11px; background-color: rgba(188, 188, 188, 50); border: 1px solid rgba(188, 188, 188, 250); }")
            self.counterSpin.setStyleSheet("QSpinBox { color: rgb(50, 50, 50); font-size: 11px; background-color: rgba(255, 188, 20, 50); }")
    
            self.totalLabel.setStyleSheet("QLabel { color: rgb(50, 50, 50); font-weight:bold; font-size: 11px; background-color: rgba(26, 188, 182, 150); border: 1px solid rgba(26, 188, 182, 255); }")
            self.totalOutput.setStyleSheet("QLabel { color: rgb(50, 50, 50); font-weight:bold; font-size: 11px; background-color: rgba(26, 188, 182, 50); border: 1px solid rgba(26, 188, 182, 255); }")
    
            self.setGeometry(800, 400, 250, 80)
            self.setWindowTitle('Simple Calculator')
            self.show()
    
    def main():
    
        app = QtGui.QApplication(sys.argv)
        ex = Example()
        sys.exit(app.exec_())
    
    
    if __name__ == '__main__':
        main()
    


Answer: If I am not mistaken, stylesheets of a parent are applied to all children
unless overwritten.

You can try this:

    
    
        # STYLING
        self.setStyleSheet("QLabel { color: rgb(50, 50, 50); font-size: 11px; background-color: rgba(188, 188, 188, 50); border: 1px solid rgba(188, 188, 188, 250); } QSpinBox { color: rgb(50, 50, 50); font-size: 11px; background-color: rgba(255, 188, 20, 50); }")
    
        #setting CS of self (the widget) and not the children
    
        self.setGeometry(800, 400, 250, 80)
        self.setWindowTitle('Simple Calculator')
        self.show()
    

Concerning your different buttons:

    
    
    label1.setProperty('labelClass', 'red')
    label2.setProperty('labelClass', 'blue')
    

and in the CS of the widget:

    
    
    QLabel[labelClass="red"] {...}
    QLabel[labelClass="blue"] {...}
    

