id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
19213	Unicode problem loading 500 template using Python 3.3	adj7388@…	nobody	"'''Environment:'''
Python 3.3
Django-1.5a1
Windows XP

To reproduce this error, work through the tutorial until you get to ""Write your first view"" section at: https://docs.djangoproject.com/en/1.5/intro/tutorial03/#write-your-first-view

Introduce an intentional error, for example in 'views.py' change:
from django.http import HttpResponse
to
from django.http import HttpResponseFoo

This produces an error as expected, but while processing the error, another exception is generated:

{{{
""During handling of the above exception, another exception occurred:""
... <snip> ...
  File ""C:\home\alan\venvs\Django-1.5a1\lib\site-packages\django\views\debug.py"", line 390, in get_traceback_frames
    pre_context_lineno, pre_context, context_line, post_context = self._get_lines_from_file(filename, lineno, 7, loader, module_name)
  File ""C:\home\alan\venvs\Django-1.5a1\lib\site-packages\django\views\debug.py"", line 361, in _get_lines_from_file
    match = re.search(br'coding[:=]\s*([-\w.]+)', line)
  File ""C:\home\alan\venvs\Django-1.5a1\lib\re.py"", line 161, in search
    return _compile(pattern, flags).search(string)
TypeError: can't use a bytes pattern on a string-like object
}}}

Line 361 in debug.py is where things start to go wrong:

{{{
    match = re.search(br'coding[:=]\s*([-\w.]+)', line)
}}}

The 'line' argument is a unicode string (type: str), but the regex is a byte pattern. You can get past this error by encoding line as 'ascii':

{{{
    match = re.search(br'coding[:=]\s*([-\w.]+)', line.encode('ascii'))
}}}

but then you run into a similar problem a few lines later (debug.py line 365):

{{{
    source = [six.text_type(sline, encoding, 'replace') for sline in source]
}}}

which produces the error '''""TypeError: decoding str is not supported""''' because 'six.text_type' is actually the Python 'str()' function, and the code is telling 'str()' to decode 'sline' using the 'ascii' codec.

Basically the 'source' list is read in from a file that produces unicode, but subsequent code thinks lines from the 'source' list are bytes and tries to apply a byte pattern regex (debug.py lines 361) or tries to decode the unicode (debug.py lines 365).

I would submit a patch if I knew how to fix the underlying problem, but I'm not sure if the fix needs to happen in 'debug.py' or in the loader that gets the 'source' list."	Bug	closed	Python 3	1.5-alpha-1	Normal	worksforme			Unreviewed	0	0	0	0	0	0