deletion_strategies.py

async def delete_n_messages(channel, amount, check=None, is_bot=True):
    """Delete a specific amount of messages.

    Only messages from the past 14 days will be deleted.

    If the bot is not a bot account, messages will be deleted one at a time.

    Parameters
    ----------
    amount: int
        The maximum amount of messages which will be deleted.
    check: callable
        Same as ``check`` in ``discord.TextChannel.purge``.
    is_bot: bool
        Whether or not the bot is a bot account.

    Returns
    -------
    int
        The number of messages which were deleted.
    """

    if check is None:
        check = lambda m: True
    strategy = _slow_deletion
    if is_bot:
        strategy = _mass_purge
    return await strategy(channel, amount, check)


async def _mass_purge(channel, amount, check):
    iterator = channel.history(limit=None)
    remaining = amount
    cur_count = 0
    to_delete = []

    minimum_time = (  # I definitely know how this works Kappa
        int((time.time() - 14 * 24 * 60 * 60) * 1000.0 - 1420070400000) << 22)

    async for msg in iterator:
        if cur_count == 100:
            # we've reached a full 'queue'
            await channel.delete_messages(to_delete)
            cur_count = 0
            await asyncio.sleep(1)
        if msg.id < minimum_time or remaining <= 0:
            # older than 14 days
            break
        if check(msg):
            cur_count += 1
            to_delete.append(msg)
        remaining -= 1
    if cur_count >= 2:
        # more than 2 messages -> bulk delete
        await channel.delete_messages(to_delete)
    elif cur_count == 1:
        # delete a single message
        await to_delete[-1].delete()
    return amount - remaining


async def _slow_deletion(channel, amount, check):
    iterator = channel.history(limit=None)
    remaining = amount

    minimum_time = (
        int((time.time() - 14 * 24 * 60 * 60) * 1000.0 - 1420070400000) << 22)
    async for msg in iterator:
        if msg.id < minimum_time or remaining <= 0:
            # older than 14 days
            break
        if check(msg):
            await msg.delete()
        remaining -= 1
    return amount - remaining