django.core.urlresolvers.reverse_helper doesn't support full regex syntax

[forest@…]

reverse_helper doesn't support the full syntax offered by the Python re module. Actually, it probably can't support everything.

(Opinion: parsing regexes is difficult and dangerous; are you sure you want to do that?)

Here is my example that failed:

^{account(?:/(?P<subpath>.*))?$}

The current implementation does not pretend to support nested parentheses. I am slightly skeptical that this approach can deal well with the trailing ? above.

-Forest

[Malcolm Tredinnick]

Parsing regexps is hardly dangerous. Let's keep some perspective. It is difficult and if you have a better way to do reverse matching, please post a patch.

The functionality requested here is a dupe of #2977.