Embed images into an HTML document with data URIs

embedder.py

#!/usr/bin/env python3
"""
Embed images into an HTML document
"""

import base64, mimetypes, re, sys

## from https://gist.github.com/jsocol/1089733
def img_to_data(path):
    """Convert a file (specified by a path) into a data URI."""
    with open(path, 'rb') as o:
        img_data = o.read()
    return 'data:{};base64,{}'.format(
        mimetypes.guess_type(path)[0],
        base64.b64encode(img_data).decode('ASCII'))

if __name__ == '__main__':
    html = sys.stdin.read()

    for path in [x[0] or x[1] for x in re.findall(
            r'''<\s*img[^>]*?\ssrc\s*=\s*(?:"([^"]+)"|'([^']+)')''',
            html, flags = re.IGNORECASE)]:
        html = html.replace(path, img_to_data(path))

    print(html, end = '')