Update streamer.py

[Quenos]

Fixing issue #100

Description

Related issue(s)

Fixes ...

Pre-merge checklist

• Passing tests
• New tests added (if applicable)

[Quenos]

Why is this failing?
Because channel is an event type.

[Graeme22]

It looks like here

channel = next((k for k, v in self._channels.items() if v == message['channel']), None)

self._subscription_state[channel]...

It's complaining that if the iterator is exhausted, the _subscription_state dict will be accessed with None as a key which will fail. You can omit the second argument, None, from the next function; that way, it'll raise an exception if the iterator reaches the end instead of passing None to the dict.

Alternatively, you could make channel a dict mapping int to the event type instead of the other way around.

[Quenos]

Apparently it broke something else now

[Graeme22]

Nope it's working well!