def load(self, filename, create_if_missing=True):
        filename = Path(filename)
        if not filename.exists() and create_if_missing:
            self.load_pip_requirements()
            with filename.open("w") as f:
                f.write(yaml.dump(self.serialized, default_flow_style=False,
                                  encoding=None))
            self.filename = filename
            return self.save(filename)
        with filename.open() as f:
            for group, requirements in yaml.load(f.read()).items():
                for requirement in requirements:
                    self[group].add(Requirement.coerce(requirement))
        self.filename = filename
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"))