CODEWITHSUNDEEP
pythonpython-2.7jinja2
AHB
AHB

Reputation: 129

How to set optional arguments in jinja2

I have used jinja2 to generate a json template. The json template is generated as expected. However, How do I make some parameters optional. For instance, In the below template sam, uri_2 and uri_3 are optional. When I don't pass the values for them in template.render, I don't want those parameters returned in the template. Currently, empty values are returned for those parameters. 

from jinja2 import Template

template = Template(''' 
        {
          "start": "{{start}}",    
          "end": "{{end}}",
          "sam": "{{sam}}",
          "res": "{{res}}",
          "uris": 
          [
             "{{uri_1}}",
             "{{uri_2}}",
             "{{uri_3}}"
          ]
        }   

        ''')

        payload = template.render(start=1560009000, end=1560009000, res=3, uri="abc.com")

output:

{"end": "1540995788", "res": "3", "sam": "", "start": "1540390988", "uris": ["abc.com", "", ""]}

Upvotes: 3

Views: 7042

Answers (1)

T Burgis
T Burgis

Reputation: 1435

In terms of parameters not passed at all (e.g. sam in your example) then 

{% if sam %}   
    "sam" : "{{ sam }}"
{% else %}      
{%endif %}

You should probably pass your uri values as a list then do something like this in the template:

"uris":
[
    {% for uri in uris %}
    "{{ uri }}"
    {% endfor %}
]

If there are no uri values and you are not passing a list to render.template then you could omit the "uris" tag completely in a similar fashion to sam.

Upvotes: 9

Related Questions