Jinja2

External

• https://medium.com/knoldus/jinja2-template-the-modern-design-friendly-templating-engine-a9218fec96e5
• https://jinja.palletsprojects.com/en/2.11.x/
• https://pypi.org/project/Jinja2/

Internal

• Templating in Python
• Templating
• Jinja Filters

Programming Model

Find out what the latest version is from https://pypi.org/project/Jinja2/

Then add this to your requirements.txt

jinja2 == 3.0.3

Once the virtual environment is updated, use it as such:

from pathlib import Path
from jinja2 import Environment, FileSystemLoader

template_dir = Path('...')
yaml = Environment(loader=FileSystemLoader(template_dir))\
  .get_template('my-template.yaml.j2') \
  .render(variable_1='some value', variable2='some other value')

Templating Language

Variable

raw content followed by {{ variable1 }}

Conditional

{%if some_var == "something" -%}
something
something else {{ var_1 }}
{% else %}
something completely different {{ var_2 }}
{%- endif %}

This works with empty strings too:

{%if some_var != "" -%}
my var is {{ some_var }}

To check whether a variable is defined or not defined:

{%if some_var is defined  -%}
something
{%- endif %}

{%if some_var is not defined  -%}
something else
{%- endif %}

Whitespace Management

A leading dash removes all whitespace (including new lines) between the last non space template character and it. A trailing dash removes all whitespace (including new lines) between it and the next non-whitespace character from the template.

 {{-

 -}}

 {%-

 -%}