Check if key exists in a Python dict in Jinja2 templates

You can test for key definition this way:

{% if settings.property is defined %}

#...
{% endif %}

Like Mihai and karelv have noted, this works:

{% if 'blabla' in item %}
  ...
{% endif %}

I get a 'dict object' has no attribute 'blabla' if I use {% if item.blabla %} and item does not contain a blabla key