DevNet Data Formats XML, JSON, and YAML in review, and what to expect on exam day / what you will want to know!


Above is a screen snip of the properly formatted data formats from previous posts

(Let me start by saying I have never taken or heard anything about the Cisco DevNet exam that was not presented on DevNet Day 2020 in June)

In the real world I know there are templates in open GIT Repositories for probably just about everything, but for DevNet exam day, I honestly don’t know this but I strongly assume you will need to put together a piece of working code as demo’d on “DevNet Day” this year during Cisco Lives Virtual days.

I would even steal the exact code I used, or make up your own fields like lists that apply to your life, and put it into Visual Studio Code and play with the formatting so when you need to piece snippets of code together to form a proper line or chunk of data formatting you absolutely know how to do it.

If you were asked to look at a Data Format like the output I have gone through, and were asked “What are the Siblings of the Second Parent in this Data Format shown below?”

I would immediately think Parent and Siblings = XML DOM that provides this Parent / Sibling relationship in my example of AwesomeFood (Parent) and Food Types (Siblings):


XML = < > and like HTML all “Tags” must close </x> in a BB Forum Code fash (bold, italic, etc), and is the one language with legacy support for SOAP (if that comes up).

“sh run | format” will present Cisco IOS output in its native XML Format.

JSON = Java Script Object Notation, uses Curly Brackets (Elements) that contain Key: Value pairs, the Key must always be in double quotes ” “, and the formatting can really be all over the place (it can actually be condensed into on long line filled with brackets or regular brackets / braces [ ] which are arrays.

Most Popular by far Data Format, Light Weight, Native to JavaScript

YAML = Human Readable Data format so much its almost not even hardly a Data Formatting for a Computer, however it does adhere to the Key: Pair logic and much more strictly to indentation to be a valid computer readable format. It includes some more flexibility with “values” like Floats, using the \n to output multiple lines, etc.

All of these are not scripting, these are ASCII Data Format types!

I know I have some clean up to do in calling some of these scripts, but these are actually Data Formats that are legible both to machines and humans (that are trained to read them like us), Python is scripting but these are just Data Format types.

My parting advice is not to just know the what the code looks like, but play with it!

I’d actually advise even just dipping your toes into making a local GIT Repository on your machine, integrating it to Visual Studio Code, so you can get used to the process of Version Control like making commits often with good short details commit comments.

Don’t just know it, play with it, understand how to break it and make it work again.

Easy points on exam day and at the interview, learn it, and love it my fellow geeks!

Also not to mention or downplay even a little bit this very important point:

Automation is so incredibly powerful, it doesn’t seem to be fully realized yet, but once the IT community embraces and appreciates its power you will be thanking yourself for committing yourself to learning it while it was still on the rise! 🙂

Nothing worth getting is easy, its hard work, and it’s what we IT geeks live for!!!

Until next time fellow geeks!

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