YAML ain't markup language. But it is. YAML is a 'data serialisation standard', or basically a way to convert your data into a text format that can be converted back while maintaining integrity. It's technically a superset of JSON, which means you can use JSON syntax within it. Check out the spec.
Why should you learn yet another thing like this? Why shouldn't we just use JSON. Well, like when we went from csv to XML, then XML to JSON, YAML is just a little easier on the eyes. Yaml is more strict on parsing too, so no duplicate keys like in JSON.
Basic as you can get
Three hyphens at the top of the text file indicates that the content is in YAML format.
Ooooh look! You can comment!
--- # My first yaml
Array, list, sequence
All the same to me. This would generate an array.
- Tom - Dick - Harry
--- face: 9 # Out of 2 I'd give her one body: 4 # I'm kinda outta shape activity: 3 # Divvent dee much
Listing out all this stuff would be really boring. Instead take a look at the examples.
Yaml will know if your content is a string or numeric based on the data type. You can wrap it around quotes, single or double, if you want.
Yaml is also like Python in that it is based on spacing, so you can have a nested array based on spacing.
--- - - 1 - 2 - - 3 - - 5
--- - a: test - b: - 1 - 2