Jinja Map: How to Extract Specific Values From a List of Dictionaries

Rick Donato

Oct 25, 2024 1 min read

Jinja Tip:
Use Jinja's map to extract specific values from a list of dictionaries. Perfect for pulling out IPs, interfaces, or other attributes within your Jinja templates or Ansible playbooks.

Example below:

# Input data
interfaces: 
  - { device: 'spine1', interface: 'GigabitEthernet0/0', ip: '10.1.1.1' }
  - { device: 'spine1', interface: 'GigabitEthernet0/1', ip: '10.1.2.1' }
  - { device: 'spine2', interface: 'GigabitEthernet0/0', ip: '10.2.1.1' }
  - { device: 'spine2', interface: 'GigabitEthernet0/1', ip: '10.2.2.1' }
  - { device: 'leaf1',  interface: 'GigabitEthernet0/0', ip: '10.1.1.2' }
  - { device: 'leaf1',  interface: 'GigabitEthernet0/1', ip: '10.2.1.2' }
  - { device: 'leaf2',  interface: 'GigabitEthernet0/0', ip: '10.1.2.2' }
  - { device: 'leaf2',  interface: 'GigabitEthernet0/1', ip: '10.2.2.2' }

# Jinja syntax
{{ interfaces | map(attribute='ip') | list | pprint }}

# Result 
[
  '10.1.1.1',
  '10.1.2.1',
  '10.2.1.1',
  '10.2.2.1',
  '10.1.1.2',
  '10.2.1.2',
  '10.1.2.2',
  '10.2.2.2'
]

Try it yourself