How do I export/archive a whole chat channel I have access to?

I'm a noob at this. I try 'python3 scrape.py -c general -o talk.txt' and it errors back with

Scraping messages... Don't send any messages while scraping!

0 messages [00:00, ? messages/s]

Ignoring exception in on_ready

Traceback (most recent call last):

File "/usr/local/lib/python3.5/dist-packages/discord/client.py", line 307, in _run_event

yield from getattr(self, event)(*args, **kwargs)

File "scrape.py", line 27, in on_ready

async for msg in client.logs_from(channel, 10000000000):

File "/usr/local/lib/python3.5/dist-packages/discord/iterators.py", line 173, in anext

msg = yield from self.iterate()

File "/usr/local/lib/python3.5/dist-packages/discord/iterators.py", line 115, in iterate

yield from self.fill_messages()

File "/usr/local/lib/python3.5/dist-packages/discord/iterators.py", line 123, in fill_messages

data = yield from self._retrieve_messages(retrieve)

File "/usr/local/lib/python3.5/dist-packages/discord/iterators.py", line 141, in _retrieve_messages_before_strategy

data = yield from self.client._logs_from(self.channel, retrieve, before=self.before)

File "/usr/local/lib/python3.5/dist-packages/discord/http.py", line 198, in request

raise HTTPException(r, data)

discord.errors.HTTPException: BAD REQUEST (status code: 400)

/r/discordapp Thread Parent