Vibe-coded script to normalize an SVG file

normalize_svg.py

import argparse
import math
import xml.etree.ElementTree as ET
from svgelements import SVG


def calculate_bbox(svg):
    """
    Calculate the bounding box of drawable SVG content.

    Returns:
        (xmin, ymin, xmax, ymax)
    """
    bbox = None

    for element in svg.elements():
        # Ignore elements that are explicitly hidden.
        try:
            if (
                element.values.get("visibility") == "hidden"
                or element.values.get("display") == "none"
            ):
                continue
        except AttributeError:
            pass

        element_bbox = element.bbox()
        # try:
        #     element_bbox = element.bbox()
        # except (AttributeError, TypeError, ValueError):
        #     continue

        if element_bbox is None:
            continue

        if not all(math.isfinite(value) for value in element_bbox):
            print(f"Not all the bounds are finite: {element_bbox}")
            continue

        xmin, ymin, xmax, ymax = element_bbox

        if bbox is None:
            bbox = [xmin, ymin, xmax, ymax]
        else:
            bbox[0] = min(bbox[0], xmin)
            bbox[1] = min(bbox[1], ymin)
            bbox[2] = max(bbox[2], xmax)
            bbox[3] = max(bbox[3], ymax)

    if bbox is None:
        raise ValueError("SVG contains no drawable geometry")

    return tuple(bbox)


def normalize_viewbox(input_filename, output_filename, padding=0):
    """
    Replace the SVG's viewBox with the bounding box of its artwork.

    The SVG is parsed with svgelements only for geometry calculation.
    The actual SVG document is parsed and written using ElementTree.
    """

    svg = SVG.parse(input_filename)
    xmin, ymin, xmax, ymax = calculate_bbox(svg)

    xmin -= padding
    ymin -= padding
    xmax += padding
    ymax += padding

    width = xmax - xmin
    height = ymax - ymin

    if width <= 0 or height <= 0:
        raise ValueError(f"Invalid bounding box: " f"{xmin}, {ymin}, {xmax}, {ymax}")

    ET.register_namespace("", "http://www.w3.org/2000/svg")

    # Parse the ORIGINAL SVG document.
    tree = ET.parse(input_filename)
    root = tree.getroot()

    # Change only the semantic SVG attribute.
    root.set(
        "viewBox",
        f"{xmin:g} {ymin:g} {width:g} {height:g}",
    )
    root.set("width", f"{width:g}")
    root.set("height", f"{height:g}")

    # Write the original XML structure back out.
    tree.write(
        output_filename,
        encoding="utf-8",
        xml_declaration=True,
    )

    print(f"Input:      {input_filename}")
    print(f"BBox:       {xmin:g} {ymin:g} {xmax:g} {ymax:g}")
    print(f"New size:   {width:g} × {height:g}")
    print(f"New viewBox:{xmin:g} {ymin:g} {width:g} {height:g}")
    print(f"Output:     {output_filename}")


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("input")
    parser.add_argument("output")
    args = parser.parse_args()

    normalize_viewbox(args.input, args.output)


if __name__ == "__main__":
    main()