Telethon python library: Mini-script for obtaining web_preview text

example

    def collect_article(self, blocks) -> str:
        article = []

        for block in blocks:
            text = self.obtain_text(block)
            if text:
                article.append(text)

        return '\n'.join(article)

    def obtain_text(self, block):
        if hasattr(block, 'text'):
            attr = getattr(block, 'text')
            if isinstance(attr, str):
                return attr
            elif hasattr(attr, 'texts') and isinstance(getattr(attr, 'texts'), list):
                texts = []
                for text in getattr(attr, 'texts'):
                    texts.append(self.obtain_text(text))
                return ''.join(texts)
            else:
                return self.obtain_text(attr)
        else:
            return None