Add QT GUI to Python for plotting graphics

from PyQt5 import QtWidgets, uic
import sys
import numpy as np

class MainWindow(QtWidgets.QMainWindow):
    
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
         # Load the UI Page
        self. ui = uic.loadUi('mainwindow.ui', self)
        # Create a sin wave
        x_time = np.arange(0, 100, 0.1);
        y_amplitude = np.sin(x_time)
        
        pltSignal = self.widgetSignal
        pltSignal.clear()
        pltSignal.setLabel('left', 'Signal Sin Wave', units ='(V)')
        pltSignal.setLabel('bottom', 'Time', units ='(sec)')
        pltSignal.plot(x_time, y_amplitude, clear = True)

        self.ui.show()

def main():
    app = QtWidgets.QApplication(sys.argv)
    window = MainWindow()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()