Quick and dirty function to extract image URLs from markdown.

find_image_urls_in_markdown.py

from collections.abc import Iterable
import urllib


def find_image_urls_in_markdown(s: str) -> Iterable[str]:
    context = ""
    alt_text_chars = []
    url_chars = []
    for char in s:
        if context == "":
            if char == "!":
                context = "after_exclamation"
        elif context == "after_exclamation":
            if char == "[":
                context = "alt_text"
        elif context == "alt_text":
            if char == "]":
                context = "alt_text_end"
            else:
                alt_text_chars.append(char)
        elif context == "alt_text_end":
            if char == "(":
                context = "url"
            else:
                alt_text_chars.clear()
                context = ""
        elif context == "url":
            if char == ")":
                yield from find_image_urls_in_markdown("".join(alt_text_chars))
                yield "".join(url_chars).strip()
                # Use next line instead to escape special chars
                #yield urllib.parse.quote("".join(url_chars).strip().encode('utf-8'), safe="/:")
                alt_text_chars.clear()
                url_chars.clear()
                context = ""
            else:
                url_chars.append(char)