title: PYQT5 drawing line
body: <pre><code>def __init__(self):
      super().__init__()
      self.title = 'Main menu'
      self.left = 80
      self.top = 80
      self.width = 1500
      self.height = 1000
      self.initUI()
  
  
  def initUI(self):
      self.setWindowTitle(self.title)
      self.setGeometry(self.left, self.top, self.width, self.height)
  
      painter = QPainter(self)
      painter.setBrush(Qt.black)
      painter.setPen(QPen(Qt.black, 2, Qt.SolidLine))
      painter.drawLine(200,200,400,400)
  
      self.show()
  </code></pre>
  
  <p>I am trying to draw a straight line but It is not drawing nothing. How can I draw it?    </p>