Are special characters (dashes, dots, semilicons, ...) allowed in dictionary keys in Ansible? - ansible

Question

I have an issue with a playbook, and wonder if the issue is that some key names in the dictionary I use have special character, namely, a dash in them. Ansible is not clear wether this is allowed or not.
The tasks:
- debug:
var: block_storage_route
- debug:
var: block_storage_route[0].table-id
vars:
block_storage_route:
- "table-id": 0
Output:
TASK [debug] ******************************************************
ok: [example.com] => {
"block_storage_route": [
{
"table-id": 0
}
]
}
TASK [debug] ******************************************************
ok: [example.com] => {
"block_storage_route[0].table-id": "VARIABLE IS NOT DEFINED!"
}
As you can see I get a "VARIABLE IS NOT DEFINED" error, although the key table-id is present in the debug of the variable block_storage_route.
Why is that?

Answer 1

Q: "Are special characters allowed in dictionary keys in Ansible?"
A: Yes. They are. In fact, there are no restrictions in YAML on the keys. Quoting from Mapping (aka Python dictionary)
"The content of a mapping node is an unordered set of key: value node pairs, with the restriction that each of the keys is unique. YAML places no further restrictions on the nodes. In particular, keys may be arbitrary nodes, ..."
Use bracket notation instead of the dot notation when the name of the key doesn't comply with Ansible Creating valid variable names
- debug:
var: block_storage_route[0]['table-id']