title: Django: error at / bad character in group name
body: <p>I was following Apress - Practical Django Project by James Bennet and I got this nasty error out of the blue. Could you help me?</p>
  
  <p>Here it goes:</p>
  
  <pre><code>Environment:
  
  Request Method: GET
  Request URL: http://127.0.0.1:8000/
  Django Version: 1.2.5
  Python Version: 2.5.4
  
  Installed Applications:
  ['django.contrib.auth',
   'django.contrib.contenttypes',
   'django.contrib.sessions',
   'django.contrib.sites',
   'django.contrib.messages',
   'django.contrib.admin',
   'django.contrib.flatpages',
   'cms.search',
   'coltrane',
   'tagging']
  
  Installed Middleware:
  ('django.middleware.common.CommonMiddleware',
   'django.contrib.sessions.middleware.SessionMiddleware',
   'django.middleware.csrf.CsrfViewMiddleware',
   'django.contrib.auth.middleware.AuthenticationMiddleware',
   'django.contrib.messages.middleware.MessageMiddleware')
  
  
  Traceback:
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/core/handlers/base.py" in get_response
    91.                         request.path_info)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/core/urlresolvers.py" in resolve
    215.             for pattern in self.url_patterns:
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/core/urlresolvers.py" in _get_url_patterns
    244.         patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/core/urlresolvers.py" in _get_urlconf_module
    239.             self._urlconf_module = import_module(self.urlconf_name)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/utils/importlib.py" in import_module
    35.     __import__(name)
  File "/Users/danielcorreia/Sites/test_Django/cms/../cms/urls.py" in &lt;module&gt;
    21.   (r'', include('django.contrib.flatpages.urls')),
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/conf/urls/defaults.py" in patterns
    24.             t = url(prefix=prefix, *t)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/conf/urls/defaults.py" in url
    41.         return RegexURLPattern(regex, view, kwargs, name)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/django/core/urlresolvers.py" in __init__
    89.         self.regex = re.compile(regex, re.UNICODE)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/re.py" in compile
    188.     return _compile(pattern, flags)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/re.py" in _compile
    241.         raise error, v # invalid expression
  
  Exception Type: error at /
  Exception Value: bad character in group name
  </code></pre>
  
  <p>Oh! I'm a newbie to Django. Please be gentle :)</p>
  
  <p>Here's the urls.py:</p>
  
  <pre><code>from django.conf.urls.defaults import *
  
  # Uncomment the next two lines to enable the admin:
  from django.contrib import admin
  admin.autodiscover()
  
  urlpatterns = patterns('',
      # Example:
      # (r'^cms/', include('cms.foo.urls')),
  
      # Uncomment the admin/doc line below to enable admin documentation:
      # (r'^admin/doc/', include('django.contrib.admindocs.urls')),
  
      # Uncomment the next line to enable the admin:
      (r'^admin/', include(admin.site.urls)),
      (r'tiny_mce/(?P&lt;path&gt;.*)$', 'django.views.static.serve', { 'document_root': '/Users/danielcorreia/Sites/tinymce/jscripts/tiny_mce' }),
      (r'^search/$', 'cms.search.views.search'),
      (r'^weblog/$', 'coltrane.views.entries_index'),
      (r'^weblog/(?P&lt;year\d{4})/(?P&lt;month&gt;\w{3})/(?P&lt;day&gt;\d{2})/(P?&lt;slug&gt;[-\w]+)/$', 'coltrane.views.entry_detail'),
      (r'', include('django.contrib.flatpages.urls')),
  )
  </code></pre>