Repeated lines from Jinja For Loop - ansible

Question

I am new to coding and learning for Infrastructure as Code.
Trying to pull info from a variable YAML file within a Jinja file using a for loop. It is working but it is displaying the code two additional times and I am not sure why.
{% for item in underlay[inventory_hostname]['MLAG'] -%}
{% if item == 'Odd' -%}
neighbor 192.168.255.1 peer group LEAF_Peer
{%- else %}
neighbor 192.168.255.2 peer group LEAF_Peer
{% endif %}
{%- endfor %}
Sample of entry in Underlay.yml
leaf1-DC2:
interfaces:
loopback0:
ipv4: 10.2.0.11
mask: 32
loopback1:
ipv4: 10.2.1.11
mask: 32
Ethernet3:
ipv4: 10.2.2.0
mask: 31
Ethernet4:
ipv4: 10.2.2.2
mask: 31
Ethernet5:
ipv4: 10.2.2.4
mask: 31
BGP:
ASN: 65201
spine-peers:
- 10.2.2.1
- 10.2.2.3
- 10.2.2.5
spine-ASN: 65200
MLAG: Odd
The results are:
neighbor 192.168.255.2 peer group LEAF_Peer
neighbor 192.168.255.2 peer group LEAF_Peer
neighbor 192.168.255.2 peer group LEAF_Peer
But should be:
neighbor 192.168.255.2 peer group LEAF_Peer
I took the variable file down to a single device that only has the entry for MLAG once but that still produces two additional lines and do not understand why.
The goal is to create a for loop that looks at MLAG and if it is Odd then produce the one statement or Even produce the other.

Answer 1

This happens because a string is an iterable object in both Jinja and Python.
You can test this doing:
{% for item in 'Odd' %}
Displaying one line (because of `{{ item }}`)
{% endfor %}
That would give you
Displaying one line (because of `O`)
Displaying one line (because of `d`)
Displaying one line (because of `d`)
Your fix is as simple as dropping the for loop, totally:
{% if underlay[inventory_hostname].MLAG == 'Odd' -%}
neighbor 192.168.255.1 peer group LEAF_Peer
{% else -%}
neighbor 192.168.255.2 peer group LEAF_Peer
{% endif %}