"TemplateSyntaxError: Could not parse the remainder" when sending email with triple curly braces #478
Description
Steps to recreate
from django.core.mail import mail_admins
mail_admins("TEST ", "{{{TEST}}}")
>>> TemplateSyntaxError: Could not parse the remainder: '{TEST' from '{TEST'
In my app I'm sending some string and it's required that it will be inside triple curly braces like this
some_str = "{{{TEST}}}"
When error is raised for whatever reason, mail_admins is triggered and since stacktrace contains some_str it throws
TemplateSyntaxError: Could not parse the remainder: '{TEST' from '{TEST'
This error is raised, because post_office puts my message into Template and tries to render it, but this is not my intention.
I want to send it as is.
I cannot escape it or other service will not accept it
Error trace:
In [1]: from django.core.mail import mail_admins
In [2]: mail_admins("TEST ", "{{{TEST}}}")
---------------------------------------------------------------------------
TemplateSyntaxError Traceback (most recent call last)
Cell In[2], line 1
----> 1 mail_admins("TEST ", "{{{TEST}}}")
File /usr/local/lib/python3.12/site-packages/django/core/mail/__init__.py:134, in mail_admins(subject, message, fail_silently, connection, html_message)
132 if html_message:
133 mail.attach_alternative(html_message, "text/html")
--> 134 mail.send(fail_silently=fail_silently)
File /usr/local/lib/python3.12/site-packages/django/core/mail/message.py:299, in EmailMessage.send(self, fail_silently)
295 if not self.recipients():
296 # Don't bother creating the network connection if there's nobody to
297 # send to.
298 return 0
--> 299 return self.get_connection(fail_silently).send_messages([self])
File /usr/local/lib/python3.12/site-packages/post_office/backends.py:56, in EmailBackend.send_messages(self, email_messages)
53 else:
54 attachment_files[attachment[0]] = ContentFile(attachment[1])
---> 56 email = create(
57 sender=from_email,
58 recipients=email_message.to,
59 cc=email_message.cc,
60 bcc=email_message.bcc,
61 subject=subject,
62 message=message,
63 html_message=html_body,
64 headers=headers,
65 )
67 if attachment_files:
68 attachments = create_attachments(attachment_files)
File /usr/local/lib/python3.12/site-packages/post_office/mail.py:101, in create(sender, recipients, cc, bcc, subject, message, html_message, context, scheduled_time, expires_at, headers, template, priority, render_on_delivery, commit, backend)
99 _context = Context(context or {})
100 subject = Template(subject).render(_context)
--> 101 message = Template(message).render(_context)
102 html_message = Template(html_message).render(_context)
104 email = Email(
105 from_email=sender,
106 to=recipients,
(...)
119 template=template,
120 )
File /usr/local/lib/python3.12/site-packages/django/template/base.py:154, in Template.__init__(self, template_string, origin, name, engine)
152 self.engine = engine
153 self.source = str(template_string) # May be lazy.
--> 154 self.nodelist = self.compile_nodelist()
File /usr/local/lib/python3.12/site-packages/django/template/base.py:200, in Template.compile_nodelist(self)
192 parser = Parser(
193 tokens,
194 self.engine.template_libraries,
195 self.engine.template_builtins,
196 self.origin,
197 )
199 try:
--> 200 return parser.parse()
201 except Exception as e:
202 if self.engine.debug:
File /usr/local/lib/python3.12/site-packages/django/template/base.py:484, in Parser.parse(self, parse_until)
482 filter_expression = self.compile_filter(token.contents)
483 except TemplateSyntaxError as e:
--> 484 raise self.error(token, e)
485 var_node = VariableNode(filter_expression)
486 self.extend_nodelist(nodelist, var_node, token)
File /usr/local/lib/python3.12/site-packages/django/template/base.py:482, in Parser.parse(self, parse_until)
478 raise self.error(
479 token, "Empty variable tag on line %d" % token.lineno
480 )
481 try:
--> 482 filter_expression = self.compile_filter(token.contents)
483 except TemplateSyntaxError as e:
484 raise self.error(token, e)
File /usr/local/lib/python3.12/site-packages/django/template/base.py:600, in Parser.compile_filter(self, token)
596 def compile_filter(self, token):
597 """
598 Convenient wrapper for FilterExpression
599 """
--> 600 return FilterExpression(token, self)
File /usr/local/lib/python3.12/site-packages/django/template/base.py:703, in FilterExpression.__init__(self, token, parser)
701 upto = match.end()
702 if upto != len(token):
--> 703 raise TemplateSyntaxError(
704 "Could not parse the remainder: '%s' "
705 "from '%s'" % (token[upto:], token)
706 )
708 self.filters = filters
709 self.var = var_obj
TemplateSyntaxError: Could not parse the remainder: '{TEST' from '{TEST'