[FIXED] jinja2: get first item in list whether list exists or not

Issue

For the first line below, the jinja2 template renders whether x exists or not. However, in the second line, the template only renders if x is an existing list. If it isn't I get an error (assume if x exists it is always a list with at least one item):

<p>x: {{ x }}</p>

<p>x[0]: {{ x[0] }}</p>
UndefinedError: 'x' is undefined

Is there a better way to check if a variable exists and get its first item than what I have here (I have tons of instances of x which have much longer names in my template and I'd rather not wrap it with the if clause every time):

{% if x %}
  <p>x[0]: {{ x[0] }}</p>
{% endif %

Solution

Jinja supports inline if else statements, and unlike Python also allows omitting the else.

{{ x[0] if x }}

Answered By - davidism