How can I print list values from FOR loop on a single line?

I am trying to get a nested list of dictionaries values printed to a single line using Jinja. I'm able to get them across multiple lines but I'm not sure how to get all values on a single line.

This is my example data Structure, trimmed for briefness

"interfaces": [
    {
        "display": "Ge1/0/1",
        "enabled": true,
        "id": 325,
        "ip_addresses": [],
        "label": "",
        "lag": null,
        "last_updated": "2022-05-12T22:42:29.740411Z",
        "link_peer": null,
        "link_peer_type": null,
        "mac_address": null,
        "mark_connected": false,
        "mgmt_only": false,
        "mode": {
            "label": "Tagged",
            "value": "tagged"
        },
        "mtu": null,
        "name": "Ge1/0/1",
        "parent": null,
        "rf_channel": null,
        "rf_channel_frequency": null,
        "rf_channel_width": null,
        "rf_role": null,
        "tagged_vlans": [
            {
                "display": "Data (10)",
                "id": 1,
                "name": "Data",
                "url": "http://10.10.0.144:8000/api/ipam/vlans/1/",
                "vid": 10
            },
            {
                "display": "VoIP (11)",
                "id": 3,
                "name": "VoIP",
                "url": "http://10.10.0.144:8000/api/ipam/vlans/3/",
                "vid": 11
            },
            {
                "display": "MGMT (20)",
                "id": 4,
                "name": "MGMT",
                "url": "http://10.10.0.144:8000/api/ipam/vlans/4/",
                "vid": 20
            }
        ],

This is my current Jinja2 code:

{% for interface in interfaces %}
interface {{ interface.display }}
{% for vlan in interface['tagged_vlans'] %}
untagged {{ vlan.vid }}
{% endfor %}
{% endfor %}

Which gives as my current output

interface Ge1/0/1
untagged 10

untagged 11

untagged 20

This is my expected output

interface Ge1/0/1
untagged 10,11,20

You don't need to loop here. It's much easier to join the values. In a nutshell:

{% for interface in interfaces %}
interface {{ interface.display }}
untagged {{ interface.tagged_vlans | map(attribute='vid') | join(',') }}
{% endfor %}

Meanwhile, if you ever need to loop and remove some white spaces/new lines from the output, see jinja2 whitespace control