The Python script process the Draw.io library files and "extract" the images from within it. In my case, I want to save the images as SVG and PNG files.

extract-svg-from-drawio-library.py

import base64
import json
import xml.etree.ElementTree as ET
import os

import cairosvg

process_files = [
    'Library-1.drawio',
    'Library-2.drawio'
]

for file in process_files:

    file_name = os.path.basename(file)
    directory_name = file_name.replace(".drawio", "")

    # Parse the XML file and get the mxlibrary node
    tree = ET.parse(file)
    root = tree.getroot()

    if root.tag != "mxlibrary":
        print(f"Error: {file} is not a valid mxlibrary file")
        continue

    # Extract the JSON array from the mxlibrary node
    json_array = json.loads(root.text)

    # Create the directories where the output images will be saved
    os.makedirs(f"{directory_name}/svg", exist_ok=True)
    os.makedirs(f"{directory_name}/png", exist_ok=True)

    # Iterate through every item in the JSON array
    for item in json_array:
        
        if "data" in item and "title" in item:

            # Extract the data and title from the item
            data = item["data"]
            title = item["title"]

            if "data:image/svg+xml;base64," in data:
                # Extract the base64 encoded SVG data
                svg_data = data.replace("data:image/svg+xml;base64,", "")
                # Decode the base64 encoded SVG data
                svg_bytes = base64.b64decode(svg_data)
                # Convert the SVG bytes to a string
                svg_string = svg_bytes.decode("utf-8")
                
                try:
                    # Save the SVG to a file
                    cairosvg.svg2svg(bytestring=svg_string, write_to=f"{directory_name}/svg/{title}.svg")

                    # Convert the SVG to PNG
                    cairosvg.svg2png(bytestring=svg_string, write_to=f"{directory_name}/png/{title}.png")
                except Exception as e:
                    print(f"Error converting {title} to PNG: {e}")