image.py 文件源码

def unfurl_image_url(url: str) -> Awaitable[str]:
    with DefaultClientSession() as session:
        results = await fetch_all(session, url)
        if 'twitter_cards' in results and 'image' in results['twitter_cards']:
            return results['twitter_cards']['image']
        if 'open_graph' in results and 'image' in results['open_graph']:
            return results['open_graph']['image']
        if 'oembed' in results and 'thumbnail_url' in results['oembed']:
            return results['oembed']['thumbnail_url']
        raise CommandError("Couldn't extract an image from the URL '{}'".format(url))