def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def edit_forum(forum_id):
    forum = Forum.query.filter_by(id=forum_id).first_or_404()

    form = EditForumForm(forum)
    if form.validate_on_submit():
        form.save()
        flash(_("Forum updated."), "success")
        return redirect(url_for("management.edit_forum", forum_id=forum.id))
    else:
        if forum.moderators:
            form.moderators.data = ",".join([
                user.username for user in forum.moderators
            ])
        else:
            form.moderators.data = None

    return render_template("management/forum_form.html", form=form,
                           title=_("Edit Forum"))