Very good article. Some time ago I had similar issue, where xmltodict parser parsed the data to the json and there was a case where specific structure (like interfaces in your case) contained only one element.
The result in json was similar to yours - specific element, instead of the list that contained that element was returned. This is annoying when you can't get consistent data. I don't like approach with working on pure XML using ET as it's not as convenient as working with JSON (just my opinion), but your article makes me think that in the next project i should consider it. Awesome write up!
This also makes me think about selecting proper approach. It really depends what is the overhead in the whole project on dealing with things like this and how many "if" statements you need to handle in the codebase because sometimes parsed json structure doesn't provide the elements in consistent way.
On the other hand - we would need to deal with learning curve of XML and how to parse the data using XML ET - it requires understanding the basics of XML (JSON team here!), the team needs to understand the ET framework and so on. This approach also pose a risk of huge codebase because of the XML ET nature and how it works.
As always - dealing with tradeoffs, no ideal solution in this case. I always love this kind of considerations, because i see other possible options that solves the issue in a different way rather that being sticked to the one approach, that I really understand.
Thanks!
