Return None instead of Zero

[Bre77]

Zero is a valid price but not correct. Instead fall back to None.

#1

[cabberley]

Thanks for your contribution! appreciate you not only identifying there was an issue in the way HA treated, but also providing the fix!

[Bre77]

Looks like it works how I expected now.

I am still not fully sure why the Average sensor ever needs to be unknown though, it seems the first period data is avaliable at that time, so I suspect there is a race condition or order of operations issue still with the library. I'll give it another look sometime.

[cabberley]

It will be a timing issue.
AEMO data for the 5 minute period normally isn't retrievable until somewhere between +30 to +75ish seconds after the period started. If you look at the coordinator config for my HA integration you will see I have logic that controls the period to poll the AEMO data source.
So the unknown value for period 1 is due to the call to AEMO occurring before the value has been posted by AEMO.
So the bottom line is I decided to start requesting just before we typically get the value and then stop polling at about 1.5 minutes and pause until the next 5 min period starts.

An alternative approach is to loop the AEMO data request until the publish the number.

But if you watched AEMO website a month or so ago when there was spikes going on, they basically suffered an overload and no one could get any data from the website.

Admittedly it is a basic failure of AEMO not use a Content Distribution Network like cloudflare to handle the unexpected burst. The data could easily be accessible no matter the scale of they architected it right.