#35417: RequestContext.new creates a context that cannot be flattened -------------------------------+-------------------------------------- Reporter: Lily Foote | Owner: nobody Type: Uncategorized | Status: new Component: Uncategorized | Version: 5.0 Severity: Normal | Resolution: Keywords: | Triage Stage: Unreviewed Has patch: 0 | Needs documentation: 0 Needs tests: 0 | Patch needs improvement: 0 Easy pickings: 0 | UI/UX: 0 -------------------------------+-------------------------------------- Description changed by Lily Foote:
Old description: > In > [https://github.com/django/django/blob/c187f5f9242b681abaa199173e02066997439425/django/template/library.py#L273 > InclusionNode.render] Django creates a {{{new_context}}} from two > existing contexts ({{{context}}} and {{{_dict}}}) by calling > {{{new_context = context.new(_dict)}}}. These can both be instances of > {{{RequestContext}}} leading to {{{new_context}}} also being a > {{{RequestContext}}} (I have not tried with any other context types). > However, calling {{{new_context.flatten()}}} raises a {{{ValueError}}}: > > {{{ > ValueError: dictionary update sequence element #0 has length 1; 2 is > required > }}} > > I can reproduce this in a small test: > > {{{ > from django.template.context import RequestContext > from django.test import RequestFactory, TestCase > > class RequestContextTestCase(TestCase): > def test_flatten_request_context_new(self): > factory = RequestFactory() > > request = factory.get("/foo/") > context = RequestContext(request) > context_2 = RequestContext(request) > context_3 = context.new(context_2) > > self.assertEqual( > context_3.flatten(), {"False": False, "None": None, "True": > True} > ) > }}} > > I discovered this when running Kolo on a Django admin view > (http://127.0.0.1:8000/admin/auth/user/). Kolo calls > {{{context.flatten()}}} internally when introspecting a template during > rendering, which leads to this exception: > > {{{ > Traceback (most recent call last): > File > "/home/lily/work/kloppindustries/kolo/python/src/kolo/profiler.py", line > 170, in __call__ > frame_data = processor.process( > ^^^^^^^^^^^^^^^^^^ > File "/home/lily/work/kloppindustries/kolo/python/src/kolo/plugins.py", > line 107, in process > data.update(self.process_extra(frame, event, arg, self.context)) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File > "/home/lily/work/kloppindustries/kolo/python/src/kolo/filters/django.py", > line 89, in process_django_template > template_context = template_context.flatten() > ^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/lily/.local/share/lilyenv/virtualenvs/kolo- > sandbox/3.12/lib/python3.12/site-packages/django/template/context.py", > line 120, in flatten > flat.update(d) > ValueError: dictionary update sequence element #0 has length 3; 2 is > required > }}} New description: In [https://github.com/django/django/blob/c187f5f9242b681abaa199173e02066997439425/django/template/library.py#L273 InclusionNode.render] Django creates a {{{new_context}}} from two existing contexts ({{{context}}} and {{{_dict}}}) by calling {{{new_context = context.new(_dict)}}}. These can both be instances of {{{RequestContext}}} leading to {{{new_context}}} also being a {{{RequestContext}}} (I have not tried with any other context types). However, calling {{{new_context.flatten()}}} raises a {{{ValueError}}}: {{{ ValueError: dictionary update sequence element #0 has length 1; 2 is required }}} I can reproduce this in a small test: {{{ from django.template.context import RequestContext from django.test import RequestFactory, TestCase class RequestContextTestCase(TestCase): def test_flatten_request_context_new(self): factory = RequestFactory() request = factory.get("/foo/") context = RequestContext(request) context_2 = RequestContext(request) context_3 = context.new(context_2) self.assertEqual( context_3.flatten(), {"False": False, "None": None, "True": True} ) }}} I discovered this when running Kolo on a Django admin view (http://127.0.0.1:8000/admin/auth/user/). Kolo calls {{{context.flatten()}}} internally when introspecting a template during rendering, which leads to this exception: {{{ Traceback (most recent call last): File "/home/lily/work/kloppindustries/kolo/python/src/kolo/profiler.py", line 170, in __call__ frame_data = processor.process( ^^^^^^^^^^^^^^^^^^ File "/home/lily/work/kloppindustries/kolo/python/src/kolo/plugins.py", line 107, in process data.update(self.process_extra(frame, event, arg, self.context)) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/home/lily/work/kloppindustries/kolo/python/src/kolo/filters/django.py", line 89, in process_django_template template_context = template_context.flatten() ^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/home/lily/.local/share/lilyenv/virtualenvs/kolo- sandbox/3.12/lib/python3.12/site-packages/django/template/context.py", line 120, in flatten flat.update(d) ValueError: dictionary update sequence element #0 has length 3; 2 is required }}} This is similar to #24765 and #26041. -- -- Ticket URL: <https://code.djangoproject.com/ticket/35417#comment:1> Django <https://code.djangoproject.com/> The Web framework for perfectionists with deadlines. -- You received this message because you are subscribed to the Google Groups "Django updates" group. 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