Add get_or_none method

[mojixcoder]

Hey, I'm planing to add get_or_none method to the Queryset class.
Since most of the python ORMs have implemented this method, I think it's nice for us to have it too.
What is your opinion?

[aminalaee]

Hey,

Thanks for the feedback.
We actually have that I think,

Model.query.first() will return first or None.
But Model.query().get() will get first or throw exceptions.

Does that make sense?

If you think it's not clear in the docs, we can improve that.

[mojixcoder]

I didn't know 'first' does that, so we don't need to do that.
Thank you

[aminalaee]

No worries.

Although I think we could have other shodtcuts like get_or_create or update_or_create.
They can be useful. If you feel like they're usable feel free to do them.