yt live chat downloader

download.py

import pytchat, argparse

parser = argparse.ArgumentParser()
parser.add_argument("vid_id", type=str,
                    help="video ID")
parser.add_argument("output", type=str,
                    help="output file")
args = parser.parse_args()

chat = pytchat.create(video_id=args.vid_id, processor=pytchat.JsonfileArchiver(args.output))
while chat.is_alive():
    print(f"{chat.get()['total_lines']} lines so far")

json2txt.py

import json, fileinput, sys, traceback

def parse_runs(runs):
    content = ""
    for run in runs:
        if "emoji" in run.keys():
            if "shortcuts" in run["emoji"]:
                content += run["emoji"]["shortcuts"][0]
            else:
                content += "{{" + repr(run["emoji"]["emojiId"]) + "}}"
        else:
            content += run["text"]
    return content

try:
    for l in fileinput.input():
        data = json.loads(l)
        chat_data = data["addChatItemAction"]["item"]

        if "liveChatTextMessageRenderer" in chat_data:
            chat_data = chat_data["liveChatTextMessageRenderer"]
            content = parse_runs(chat_data["message"]["runs"])
            author = chat_data["authorName"]["simpleText"]
        elif "liveChatModeChangeMessageRenderer" in chat_data:
            chat_data = chat_data["liveChatModeChangeMessageRenderer"]
            content = parse_runs(chat_data["text"]["runs"]) + " | " + parse_runs(chat_data["subtext"]["runs"])
            author = "* SYSTEM *"
        timestamp = chat_data["timestampText"]["simpleText"]

        print(f"{timestamp} <{author}> {content}")
except Exception as e:
    print(traceback.format_exc(), file=sys.stderr)
    print(chat_data, file=sys.stderr)

alright, I updated the json2txt script, should work now (failed on some emoji, possibly the transgender flag in some cases)