PyQt - clear widget for redraw

[Peter]

I want to draw some lines on a widget.
This works ok, but when I want to redraw, the old lines are still there.

How do I clear or refresh the widget, so I can draw a new set of lines?

Code snip below.

TIA

Peter


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 def paintLines(self, e):
      p = QPainter(e)
      mar = e.width()/100  # margin
      vsp = 2              # vertical spacing
      hrz = (e.width() - 2*mar)/100  # horizontal scalar
      for i in range(100):
          p.drawLine(mar,mar+vsp*i,hrz*(l1[i]+1),mar+vsp*i)
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