Jinja2 inline comments

Question

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.

Answer 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. <!-- comment --> when generating XML, etc.