FWIW I was very surprised when I realized this problem. I couldn't understand
why a model object with an email field (without `blank=True`) could be saved
with an empty string as email address.
The way I dealt with this was creating a mixin (ValidateModelMixin) and adding
it as left-most
> Use double quotes for strings meant for human consumption, use single
> quotes for everything else.
>
> Text, trans strings, model verbose_names: double quotes
> Dict keys, HTML tags, flags, and similar: single quotes
>
> Use triple quotes for long blocks of text, ideally only necessary
