def bounding_box_circle(svg, node, font_size):
    """Bounding box for circle node."""
    cx, cy = svg.point(node.get('cx'), node.get('cy'), font_size)
    r = svg.length(node.get('r'), font_size)
    return cx - r, cy - r, 2 * r, 2 * r
Bounding box for circle node.
weasyprint/svg/bounding_box.py