@client.event
async def on_ready():
    guilds = client.guilds
    data = {}
    for guild in guilds:
        data[guild.id] = []
        for channel in guild.channels:
            data[guild.id].append(channel.id)
    with open("./data/guilds.json", "w") as file:
        json.dump(data, file, indent=4)