(Pipelines) Get Users in Role / Process XML from HTTP API

I know this post is old, but it relates very well to what I'm trying to do.  I'm trying to get the user names of all people in a particular role.  There's just a couple things I don't understand in the RegEx channel.  First, how do I write the code to filter the logic in step B for a certain role (for example, Role ID = 12)?  Second, I am trying to retrieve the user's name.  It's stated that you should convert the string "group_0" to an object and can then reference the property.  How is this done?  I ultimately want to create a record with the user name or delete a record for that user name from a test table, depending on what is returned from the API_UserRoles call.

This code will filter the API_UserRoles output on a specified role and return the names as a semicolon-separated list:

{% set searchRoleId = '12' -%}
{% set users = b.json.qdbapi.users.user -%}
{% for user in users if user["@type"] == "user" -%}
{# Handle single vs array of roles -#}
{% if user.roles.role is iterable and user.roles.role is not mapping -%}
{# Array of roles -#}
{% set userRoles = user.roles.role | map(attribute='@id') | list -%}
{% else -%}
{# Single role, return as array of roles -#}
{% set userRoles = [user.roles.role['@id']] -%}
{% endif -%}
{% if searchRoleId in userRoles -%}
{{ user['name'] }}{{';' if not loop.last }}
{%- endif -%}
{% endfor -%}

Change line 1 to search for a different role id. The data returned from API_UserRoles is different if a user is a member of a single role vs multiple roles, so this code has the logic to handle both cases.

The output will look like "John Doe;Jane Smith;Bob Jones". The output of the regex step should assign a "group_0" to each of the names that you can iterate with a loop.

Hope that helps!

Here is some other code from Doug Henning about 2 years ago that seemed like it was working for my issue, but I get an error when I paste it into the Text* field for the Find All Matches to a RegEx which says that it contains invalid Jinja syntax. 

{% set users = a.json.qdbapi.users.user -%}

{% set searchRoleId = '18' -%}

{% for user in users if (user.roles.role | selectattr("@id", "eq", searchRoleId)|list|count) > 0 or user.roles.role['@id'] == searchRoleId -%} {{ user.name }} ({{user["@id"]}}){{ "," if not loop.last }}

 {% endfor -%}

I was able to run the pipeline once though, and it gave me the result I was looking for, but after that it won't allow me to run the pipeline.  And like I mentioned in my earlier post, the lengthier bit of code referenced in this post allows me to get past the syntax errors, but give me an error when I run the pipeline.

Sorry to bother you again, but I really don't understand where the problem is.  Any help is truly appreciated.  Here is a screenshot of the pipeline and error:

Wow!  Thank you so much!  I should have noticed that.  I feel kind of dumb for not noticing that.  Where can I go to learn more about how to write this type of code?  It's Jinja2, right?