Jinja2 inline comments

python macros jinja2 comments

121,516

Solution 1

Jinja2 has no support for comments within a {{ ... }} statement. You can only use comments outside of such statements, and then only with {# .. #} or ## comment.

{# .. #} is only meant for disabling part of a template or adding comments outside of other Jinja2 syntax. You can't nest these.
# statement is the equivalent of {% statement %}, if line statements are enabled and so configured.
## comment only works if line statements are enabled, at which point it regarded as a comment.

Generally, outside of Jinja statements, use comments in the target language instead; e.g.  when generating XML, etc.

Solution 2

Now Jinja2 has a comment statement:

{% comment %}

    <html code/>
    {% some other statements %}
    {{ some.values }}

{% endcomment %}

Solution 3

I was trying to add comments to Martijn Pieters.

{% .. %} = {# .. #}

{{ .. }} = {# .. #} (same as above)

121,516

kimstik

Updated on December 21, 2020

Comments

kimstik over 3 years
How can I put comments inside Jinja2 argument list declaration ?

Everything I have tried gives an error: jinja2.exceptions.TemplateSyntaxError: unexpected char u'#'
```
{{ Switch('var',
    [('1', 'foo'),    #  comment 1
     ('2', 'bar'),    ## comment 2
     ('3', 'rum'),    {# comment 3 #}
     ]) }}


{% macro Switch(var, caselist) %}
    {% for case, action in caselist%}
        CMP  {{var}} {{case}} 
        JNE  {{LABEL}}
        {{action}}
        JMP  {{LABELF}}
{{LABEL}}:  NOP
    {%- endfor %}
{{LABELF}}: NOP
{%- endmacro -%}
```
In my case Jinja2 is used as macro preprocessor for assembler.
- Ross Ridge over 4 years
  
  While you're generating assembly, your question doesn't actually seem to be related to that. You could be generating HTML or C++ and it wouldn't change your question.
- Gabriel Staples about 4 years
  
  Useful link: jinja.palletsprojects.com/en/2.11.x/templates
kimstik over 11 years

external comments looks not such pretty in my case :(
timss about 8 years

"{# .. #} is only meant for disabling part of a template" – does not match the current documentation, where it is also used as {# a comment #}.
Martijn Pieters about 8 years

@timss: That sentence should be read in the context of this question, where the OP used {# comment 3 #} within a block. Yes, {# ... #} are used for commenting, including commenting out (disabling) part of a template.
kimstik over 3 years

May I use it within a {{ ... }} statement ?
Dan Netoff over 3 years

@kimstik, sorry I dont uderstand your question. But I am edit my answer, plz see it
kimstik over 3 years

I love your approach. Stay curious and motivated. Explore a little deeper
Oren over 3 years

For some reason, I still don't have {% comment %}, but then I have used: {% if False %} instead, and I guess it is the same idea.
Ahmed almost 3 years

jinja2.exceptions.TemplateSyntaxError: Encountered unknown tag 'comment'.
old-monk about 2 years

With ansible, I get AnsibleError: template error ... unknown tag comment.