Templates that use 'label' or other attributes

[agstephens]

Note that Mark has updated pyessv so that you can specify lookups for the template parser that use alternative properties of the record, such as: label, canonicalName.

Details are here in the "Template parsing" section here:

https://github.com/ES-DOC/pyessv/blob/master/notebooks/pyessv-and-cmip6.ipynb

[piotrflorek]

Thanks for the update! I had to drop the idea of using pyessv template parsing because it was missing these and some other pieces of functionality I needed (e.g. optional terms, like dateranges, and regexp/datetime validation - although I think Mark has implemented recently).

I will wait 1-2 more weeks until the api stabilizes, and then will refactor my code using Mark's parser.