A quick script to render live chat json's downloaded from YT-DLP

printchat.py

import json

def render_chat(chats):
    chat_rendered = []
    for chat in chats:
        item = chat['replayChatItemAction']['actions'][0]
        if 'addChatItemAction' not in item:
            continue
        item = item['addChatItemAction']['item']
        if 'liveChatTextMessageRenderer' in item:
            # handle chat message
            chat_renderer = item['liveChatTextMessageRenderer']
            author = chat_renderer['authorName']['simpleText']
            message_runs = chat_renderer['message']['runs']
            timestamp_text = chat_renderer['timestampText']['simpleText']

            parsed_runs = []
            for run in message_runs:
                if 'text' in run:
                    parsed_runs.append(run['text'])
                elif 'emoji' in run:
                    parsed_runs.append(run['emoji']['shortcuts'][0])
            message = ' '.join(parsed_runs)
            chat_rendered.append(f"{timestamp_text} {author}: {message}")
            
        elif 'liveChatViewerEngagementMessageRenderer' in item:
            # handle banner or whatever
            # we probably don't care either
            pass
        else:
            # other types, we don't care
            pass
    return chat_rendered


if __name__ == "__main__":
    filename = "somelivechat.live_chat.json"

    chats = []
    with open(filename, encoding="utf-8") as infile:
        for line in infile.readlines():
            chats.append(json.loads(line))

    chat_rendered = render_chat(chats)
    
    with open("outfile.txt", 'w', encoding='utf-8') as outfile:
        for chat in chat_rendered:
            print(chat, file=outfile)