Trying to access the loop variable loop inside a nest block (even with the scoped argument) causes Jinja to report an undefined-error during rendering.
Template Code
Spam
{% for item in ["a", "list", "of", "items"] -%}
{% block spamblock scoped -%}
Foo {{ item }} {% if loop.last %}Bar{% endif %}
{%- endblock spamblock %}
{% endfor -%}
EggsExpected Behavior
Ability to access the loop variable in the nested block. The example above should produce:
Spam
Foo a
Foo list
Foo of
Foo items Bar
Eggs
Actual Behavior
Jinja reports an undefined-error
Full Traceback
Traceback (most recent call last):
File "render.py", line 6, in <module>
rendered = template.render()
File "~/.local/lib/python3.7/site-packages/jinja2/asyncsupport.py", line 76, in render
return original_render(self, *args, **kwargs)
File "~/.local/lib/python3.7/site-packages/jinja2/environment.py", line 1008, in render
return self.environment.handle_exception(exc_info, True)
File "~/.local/lib/python3.7/site-packages/jinja2/environment.py", line 780, in handle_exception
reraise(exc_type, exc_value, tb)
File "~/.local/lib/python3.7/site-packages/jinja2/_compat.py", line 37, in reraise
raise value.with_traceback(tb)
File "./template.txt", line 3, in top-level template code
{% block spamblock scoped -%}
File "./template.txt", line 4, in block "spamblock"
Foo {{ item }} {% if loop.last %}Bar{% endif %}
File "~/.local/lib/python3.7/site-packages/jinja2/environment.py", line 430, in getattr
return getattr(obj, attribute)
jinja2.exceptions.UndefinedError: 'loop' is undefinedYour Environment
- Python version: 3.7.3 [GCC 8.3.0] on linux
- Jinja version: 2.10.1
Workaround
Simply setting the loop variable to another, and using the other variable inside the nested block (and overrided blocks in inheriting child templates):
Spam
{% for item in ["a", "list", "of", "items"] -%}
{% set loop_ = loop -%}
{% block spamblock scoped -%}
Foo {{ item }} {% if loop_.last %}Bar{% endif %}
{%- endblock spamblock %}
{% endfor -%}
Eggs
Trying to access the loop variable
loopinside a nest block (even with thescopedargument) causes Jinja to report an undefined-error during rendering.Template Code
Expected Behavior
Ability to access the loop variable in the nested block. The example above should produce:
Actual Behavior
Jinja reports an undefined-error
Full Traceback
Your Environment
Workaround
Simply setting the loop variable to another, and using the other variable inside the nested block (and overrided blocks in inheriting child templates):