CODEWITHSUNDEEP
pythondjangojinja2
Amal Antony
Amal Antony

Reputation: 6807

Check if key exists in a Python dict in Jinja2 templates

I have a python dictionary:

settings = {
   "foo" : "baz",
   "hello" : "world"
}

This variable settings is then available in the Jinja2 template.

I want to check if a key myProperty exists in the settings dict within my template, and if so take some action: 

{% if settings.hasKey(myProperty) %}
   takeSomeAction();
{% endif %}

What is the equivalent of hasKey that I can use?

Upvotes: 102

Views: 131346

Answers (4)

NFSpeedy
NFSpeedy

Reputation: 171

Actually, in the style of Python, if you do a simple if statement, it will work:

{% if settings.foo %}
Setting Foo: {{ settings.foo }}
{% endif %}
{% if settings.bar %}
Setting Bar: {{ settings.bar }}
{% endif %}
{% if settings.hello %}
Setting Hello: {{ settings.hello }}
{% endif %}

Output:

Setting Foo: baz
Setting Hello: world

Cheers!

Upvotes: 1

Mihai Zamfir
Mihai Zamfir

Reputation: 2166

This works fine doesn't work in cases involving dictionaries. In those cases, please see the answer by tshalif. Otherwise, with SaltStack (for example), you will get this error:

Unable to manage file: Jinja variable 'dict object' has no attribute '[attributeName]'

if you use this approach:

{% if settings.myProperty %}

note:
Will also skip, if settings.myProperty exists, but is evaluated as False (e.g. settings.myProperty = 0).

Upvotes: 15

ma3oun
ma3oun

Reputation: 3790

You can test for key definition this way:

{% if settings.property is defined %}

#...
{% endif %}

Upvotes: 41

tshalif
tshalif

Reputation: 2612

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

Upvotes: 195

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