title: Draw on top of image
body: <p>I'm new to PyQt5 and I couldn't find any answers that worked for me about how to draw with QPainter on top of a loaded image (QPixmap("myPic.png")). I tried doing it within a paintEvent method but it didn't work. If I want to draw a line on top of the loaded image in the snippet below, how would I go about doing it? </p>
  
  <pre><code>import sys
  from PyQt5.QtWidgets import *
  from PyQt5.QtGui import *
  
  class Example(QWidget):
      def __init__(self):
          super().__init__()
          self.setGeometry(30, 30, 500, 300)
          self.initUI()
  
      def initUI(self):
          self.pixmap = QPixmap("myPic.png")
          lbl = QLabel(self)
          lbl.setPixmap(self.pixmap)
  
          self.show()
  
  if __name__ == '__main__':
      app = QApplication(sys.argv)
      ex = Example()
      sys.exit(app.exec_())
  </code></pre>