Nested lists in yaml

Question

How can I create nested lists in YAML? I want to get:

 {"Hello": ["as", ["http://", ["cat"]]]} 

Here's my YAML that doesn't work (with pyYaml):

  Hello:     - "as"       - "http://"         - cat 

What am I doing wrong?

Specifically, I'm trying to generate the following JSON from YAML:

"URL" : {   "Description" : "URL of the website",   "Value" :  { "Fn::Join" : [ "", [ "http://", { "Fn::GetAtt" : [ "ElasticLoadBalancer", "DNSName" ]}]]} } 

Here's the closest YAML I've got working, but it doesn't give quite what I need.

YAML is:

  Outputs:     URL:       Description: URL of the website       Value:         "Fn::Join":         - ""         - "http://"         - "Fn::GetAtt":           - ElasticLoadBalancer           - DNSName 

This results in:

    "URL": {         "Description": "URL of the website",          "Value": {             "Fn::Join": [                 "",                  "http://",                  {                     "Fn::GetAtt": [                         "ElasticLoadBalancer",                          "DNSName"                     ]                 }             ]         }     } 

This is almost correct, but after "" there should be a nested list, not just another list item. How can I fix this?

This is going to be fed into an API, so the output must match completely.

Answer 1

And the answer is:

URL:   Description: URL of the website   Value:     "Fn::Join":       - ""       - - "http://"         - "Fn::GetAtt":             - ElasticLoadBalancer             - DNSName 

(see http://pyyaml.org/wiki/PyYAMLDocumentation#YAMLsyntax - "block sequences can be nested")

Answer 2

Start a nested list from a new line. Using this approach it is easy to figure out.

Read this and this article. They have a lot of examples.

Try like this:

YAML

Value:     "Fn::Join":       - ""       -          - "http://"          - "Fn::GetAtt":               - ElasticLoadBalancer               - DNSName 

Equivalent JSON:

{   "URL": {     "Description": "URL of the website",     "Value": {       "Fn::Join": [         "",         [           "http://",           {             "Fn::GetAtt": [               "ElasticLoadBalancer",               "DNSName"             ]           }         ]       ]     }   } }